22 Years of Crown `Mic Memos`
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Mic
Memo
Welcome! This CD holds 22 years of Mic Memo issues — a tremendous database of
applications and information on Crown microphones — within a searchable Adobe®
Acrobat® pdf file format. Whatever your question, needs, or application, you should be
able to find useful tips on this CD.
PZM® pioneer Ken Wahrenbrock was the first editor of the PZM Memo, which later
became the Crown Mic Memo as Crown developed a full line of microphones. Ken has
since passed on. We deeply appreciate his enthusiasm for PZM mics, his willingness to
share his knowledge, and his warm spirit.
The Mic Memo issues on this CD are arranged in chronological order. To search for a
particular topic in this document, use Acrobat Reader’s FIND function. Select the binoculars
icon and enter the word or words you are searching for. Turn OFF “Match Case”.
Want to know more about stereo applications? Do a search for “stereo”. Click the binoculars
"Find again" icon until you find all the places that the word “stereo” was mentioned. Are you
interested in applications for the GLM-100? Search for “GLM” or “GLM-100”. All the app notes
for this microphone will appear, one at a time.
Most of the illustrations in this document were scanned from the published newsletters.
They will appear sharper in printouts than they do on screen.
I hope you find this compilation an invaluable tool.
Bruce Bartlett
Mic Memo Editor
Layout: Marie Turnock
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trademarks of Crown International. Other trademarks are the property of their respective
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First issue, circa summer 1978
Syn-Aud-Con Newsletter
DEVELOPMENT OF THE PZM
Fig. 1. Prototype built in May 1978 showing a close-up of the capsule mounting
Ken Wahrenbrock, a Syn-Aud-Con graduate and a very alert audio investigator, conceived of and built
a prototype of the Pressure Zone Microphone, PZM. He used as his model the drawing shown in Tech
Topic Vol 5, # 7, and a sub-miniature electret in a configuration that combined complete acoustic
integrity with a rugged, practical mounting that allowed extremely versatile placement of the units.
During the past year PZM systems have achieved a remarkable acceptance among leading professional audio engineers and members of the entertainment industry. When a microphone receives a
rave review by a serious music critic you can be sure it is different.
Fig. 2. Pressure Response technique (PRP) Microphone. Drawing from the Syn-Aud-Con Tech Topic
The model built by Syn-Aud-Con used an expensive dial vernier adjustment. Wahrenbrock’s prototype
used an inexpensive screw. At that time we didn’t know what spacing of the diaphragm from the
surface would be ideal.
WHY NOT USE FLUSH MOUNTING OF THE MICPOPHONE?
A pressure calibrated microphone when flush mounted has its on-axis response essentially in a free
field. A sound is said to be in a free field if it is uniform, away from boundaries, and is undisturbed by
other sources of sound.
A pressure calibrated microphone in a free field has a pronounced rise in its amplitude response at
high frequencies because of the undamped resonance of its diaphragm.
Fig. 3. Top: Free-field mic response. Bottom: Pressure-response mic response.
When placed in a cavity, for example, (a cavity is a pressure sound field) the response becomes
uniform with frequency. If a pressure calibrated microphone is flush mounted, then its on-axis response will not exhibit the high frequency peak noted here.
In the PZM system no signal can ever arrive on-axis but can only enter at the sides of the opening
between the microphone’s diaphragm and the metal plate. This means that not only does the PZM
maintain a “flat” response but that it does so for all angles of incidence in the hemisphere surrounding
it.
HOW CAN A MICROPHONE SO INEXPENSIVE SOUND SO MUCH
CLEANER THAN MICROPHONES LITERALLY 10 TIMES ITS COST?
Because all conventional microphones, no matter how skillfully made, no matter how esoteric the
materials they are made from, contain a severe acoustic handicap. They receive both direct and
reflected sound [actually, they receive direct and reflected sounds at different times.]
The PZM always sees the pressure field at the surface of the boundary which is totally free of the
anomolies caused by the phase cancellation of direct with reflected sound.
Fig. 4. Top: PZM response on a surface. Bottom: Conventional mic response near a surface.
PZM: A FUNDAMENTAL ADVANCE IN THE SCIENCE AND ART OF
MICROPHONY
The 1980s will witness the widespread use of the first really fundamental advance in microphony in
fifty years. The tremendous innovations of Wente, Thuras, Olsen, Bauer and others in the late Twenties and early Thirties are the basis of every conventional microphone on the market today.
Veneklausen’s concept of the “flush-mounted” microphone for stage use, circa the late Sixties, led to a
proliferation of useful mounting devices by Shure, EV, and others.
Fig. 5. Early PZM model by Ken Wahrenbrock.
THE PRP BREAKTHROUGH
Ed Long and Ron Wickersham, in studying the behavior of flush-mounted microphones, uncovered a
basic error in our thinking. Within a few millimeters of a large surface, sound levels from a pair of
equal level signals add coherently because, in close proximity to the surface, the particles are still in
phase as they accelerate after being brought to a stop by the boundary. This creates what is called a
pressure field right at the surface of the boundary.
“A pressure field is one in which the instantaneous pressure is everywhere uniform. There is no
direction of propagation.” GenRad Microphones and Accessories Instruction Manual, 1977.
Long and Wickersham utilized this insight by mounting a ½” B&K pressure-calibrated measuring
microphone perpendicularly above a formica surface with only a few hundredths of an inch spacing
between the microphone’s diaphragm and the formica surface. They named this procedure and its
method of utilization, Pressure Recording Process, PRP.
Don Davis of Syn-Aud-Con suggested that a proprietary electret capsule available to Syn-Aud-Con
graduates would be a suitable choice for such systems inasmuch as it was pressure calibrated and
much less than 1/8" in size. (Syn-Aud-Con Newsletter Vol 5, # 3 and Tech Topic Vol 5, # 7. April
1978)
Pressure Zone Microphony, PZM, is an application of the Pressure Recording Process, licensed from
E.M. Long Assoc. PZM is a trademark of Synergetic Audio Concepts [now a trademark of Crown
International]. PRP is a trademark of E.M. Long Associates.
Pressure Zone Microphones are manufacturered by WahrenbrockSound Associates, Ltd. [now mfg.
by Crown International].
WHY DON’T ALL MICROPHONE MANUFACTURERS ADOPT THIS
IDEA?
Like all fundamental departures from the ordinary, a complex of influences motivate those who first
encounter the PZM products and techniques. First, it is a patented product and a majority of the
legitimate manufacturers of conventional microphones do not violate the sanctity of a patented idea.
Secondly, evaluation of a competitive product by many engineers quickly run into the NIH factor (NIH
stands for “not invented here”).
A third, and perhaps dominate problem is “How do you measure a PZM?”.
HOW TO MEASURE A PZM
The PZM obviously can’t be measured in an anechoic chamber [not true - BB]. Only the most advanced engineering thinking has been sufficiently alert to become involved with TEF measurements
(Trademarked by Syn-Aud-Con). Time-Energy-Frequency measurements based on Richard C.
Heyser’s TDS (time delay spectrometry) patent, and its more advanced manifestations such as ETC
(energy time curves) and TFC (time frequency curves), are the only measuring tools capable of
evalating properly the actual “in situ” performance of the Pressure Zone Microphones [sorry, not true BB].
The first 600+ users of PZM have employed that most sophisticated analyzer available today, the
human ears and brain. Their ears informed them of the sonic superiority of the PZM. The early users
have made substantial contributions to their artistic employment. We then measure the objective
reasons that always stand behind an inspired artistic intuitive insight.
DOES MICROPHONE PLACEMENT TECHNIQUE HAVE TO BE RELEARNED?
To be blunt but honest, YES! What you have learned in the past was how to make the best of a
fundamentally bad situation. Some engineers have demonstrated remarkable insights into the problems and taken measures to minimize them. Observe any large complex microphone boom, for
example.
There now exists 50 years of experience with how to minimize the “barrel” sound of conventional
microphones. When you are suddenly freed of this gross distortion everything sounds good from
almost any placement. Now you have the opportunity to choose not just a good sound, but a superlative sound that really lets you record the subtle interface between the artist and the acoustic environment in a degree not experienced before. That’s where the real excitement lies.
ADDITIONAL PZM ADVANTAGES
One of the exciting facets about any new breakthrough is the, as yet, unexplored serendipities awaiting the experimenter.
One area worthy of such experimentation is the ease with which the directional discrimination characteristics of the PZM can be modified. A conventional microphone can often exhibit radical changes in
frequency response [acoustic comb filtering) near any object (including the artist). The PZM does not
[if the object is within a few thousands of an inch of the PZM mic capsule - BB]. Therefore, it is possible to use simple shields to alter the strength of the acoustic signal actually appearing at the surface
where the microphone is located without detrimental effeots on its response. [Actually, these shields or
boundaries do alter the frequency response of the PZM mic due to diffraction - BB].
For example, a piece of carpet can be laid over the top and rear of a PZM (leaving the front area
open). It is easy to obtain a 20 dB front-to-back ratio [at high frequencies - BB]. An extremely effective windscreen for the PZM can be built using a little creativity. One method, though not ideal, is to
use a darning hoop that has the foot of a ladies stocking pulled tighly over it and clamped by the outer
ring of the hoop. This gives you an exceptional two-stage windscreen that will quiet a literal gale while
not affecting the response in any way. These windscreens are more effective than the commercially
available foam types.
The pickup of live stage shows, choirs, etc., all can benefit from the directional control of the PZM.
The Pressure Zone Nicrophone works well when mounted in the center of a 4’x4' plexiglass panel
over a large orchestra or choir. The large panel serves as a very effective block to the sound from
behind the panel.
By its very nature a PZM normally has a Q of 2.
We encourage you to explore various baffling arrangements both for directional control and tonal
coloration. keeping in mind that, on occasion, the performer may be able to use extreme coloration as
an asset.
We suggest you order a pair of Pressure Zone Microphones. After experience with these units your
ears will be equipped to evaluate our written description with greater acuity, making your choice of
alternatives and alterations in the systems easier.
###
PZM MEMO
March 1979
Ken Wahrenbrock, Editor
PZM Memo is a nonlinear media of information and questions about PRP and PZM microphones,
uses, data, suggestions, pricing, modifications, etc.
Fig. 1. Early Wahrenbrock PZM prototype.
PZM MICROPHONE SPACING
The spacing between the capsule front and the boundary plate may vary up to .014 without change in
response, as testing with TDS has shown.
MICROPHONICS
The small size of the diaphragm of the cartridge reduces the inertia so that there is much less problem
with microphonics (mechanical vibration pickup) than with standard size dynamic microphones.
MICROPHONE STAND MOUNTING
Best use of the PZM is to place it on a large boundary of the room, floor, wall, ceiling, gobo or 3' x 3'
(or larger) piece of 1/8" plastic or masonite. However, if you wish to mount the mike on a stand, a
cutoff Switchcraft 2501F and a 5/8" 6-32 machine screw will mount on the back of the plate and a
short Atlas flexible section will allow positioning as you wish. One studio took excess mike holders
with the mike socket broken and bolted two of them together for an adjustable mounting.
COMPARISON TO CARDIOIDS
Testing with TDS indicates that the PZM fwill not develop the comb filters as the sound sources move,
as a cardioid does. Shifting sources are reproduced faithfully. Multiple sources can be cleanly reproduced without cancellations and comb filters.
REPORTED USES OF PZMs
PZMs have been taped to the underside of the piano lid and used for sound reinforcement with the lid
down and covered with a quilt to reduce leakage from other instruments. Some testing is necessary to
find optimum placement.
Tests have brought excited response from mixers with much experience in recording orchestra in
studios.
Las Vegas Recording used one PZM for the brass section mounted on the back of the gobo, two for
reeds, and each section had a better mix and could hear others in the section better.
When confronted with a Model C [discontinued] on a stand, the soloist said, “That can’t be a mike! I
can’t sing into that!” They placed a U-87 next to the PZM, recorded 2 channels and let her choose.
She liked the PZM sound better.
Recent tests have been made with the LA Philharmonic with PZMs and two other stereo systems.
At another session, the LA Philharmonic was recorded in a studio with 2 PZMs spaced 20' apart on
the ceiling, 24' above the director and about 8' behind him.
Lavalier and model D versions [discontinued] have been used in film and TV production.
A recording with a PZM and 1" of foam screen for a close solo microphone provided a recording that,
heard on Time-Aligned speakers, located the soloist right in one’s ears.
Several studios have recorded PZMs on 4’x4' panels, gobos or isolation panels. Excellent piano
pickup is obtained with the microphone on a panel 6' away and parallel to lid on high stick.
One studio has used 2 PZMs for drum pickup in a drum booth with outstanding results.
In a band with a large percussion section, the percussionist strapped a PZM to his chest and carried
his mike from kettle drums to chimes to cymbals, etc.
PZM microphones were used for the piano pickup on the 1979 American Music Awards and Grammy
Awards shows. They were also used for the Academy Awards.
###
PZM MEMO
August 1979
Ken Wahrenbrock, Editor
MICROPHONE PATTERNS
The PZM pickup pattern should properly be termed hemispherical (when the mic is on a boundary).
A cardioid pickup pattern can be created by using carpet. A 20 dB attenuation toward the rear at high
frequencies is measured using TDS. Use a double layer of carpet folded over.
WORDS WE LIKE TO HEAR
Reynold Weidenaar, Free-lance musician, New York City: “Thanks for the PZMemo and thanks for
the best mics in my collection!”
From the L.A. Times, July 9, 1979 Music Review, on the all-Mozart evening Robert Shaw conducted in
the Hollywood Bowl on Friday night, July 6th:
“The star of the evening, then, turned out to be the discreet and newly generalized microphoning on
the Bowl stage. With apparent naturalness and unobtrusively, it delivered the music to the outdoor
auditors without distortion. That is, of course, saying a lot.”
Ron Streicher, Pacific Audio-Visual Enterprises, Monrovia, CA, on use of PZM for the Metropolitan
Opera at the Robin-hood Dell in Philadelphia: “Critics, audience, staff, and — of course — sound
crew were all very pleased with the results of these mics. And their performance has prompted interest in other stage applications, as well.”
Martin Towne, Spellbound Sound, Ft. Myers, Florida: “I might expect that the next few years may
show us that the PZM may be one of the most important developments in the audio field in this decade.”
A. Bruce Jacobs, Fargo, N.D.: “First of all, I like the microphone! What a piano sound! I think you
should offer an option for altar-top usage that would provide the aluminum back plate with big arrows
and letters saying, ‘THIS IS A MICROPHONE.’ (I love it.)”
Richard Jamieson, Jamieson & Associates, Minneapolis: “We are extremely happy with the Model A
PZM microphones.”
PZMs FOR OPERA
We’re pleased to have had several good, constructive critiques of the PZM mikes from various users
across the country. Here are some gleanings from these reports and our responses.
From Ron Streicher on its use at the Metropolitan Opera performances at the Robinhood Dell, Philadelphia:
Faced with the problem of micing the Metropolitan Opera without the mics being seen by the audience, I decided to try the (new) technique of pressure-zone micing, using the PZM microphones of
Ken Wahrenbrock’s design. Having previously tried various types of mics and not really being satisfied
with any of the results, I had reservations about this unusual’ technique. The results were more than
gratifying.
The three mics I ordered from Ken arrived only a few days prior to the first performance. When they
were tested with the sound system at the Dell, all seemed ok so to see what they would sound like, I
used one on the stage in front of the regular soloist’s stand (bearing an AKO D-224) for a graduation
ceremony which Temple University’s Law School was holding at the Dell. As often happens, the
soprano came out and stood some fifteen feet away from her stage mark. The AKG, of course, being
useless, up came the PZM. Up came the soprano! I was amazed.
There was not time for rehearsal before the Metropolitan Opera’s performance, which is a nightmare
for the sound department. No chance to set levels or balances, with 10,000-plus people in the audience (including not always friendly critics) all waiting to hear Luciano Pavorotti. Having set an approximate balance, I was in the bleacher area in the back and my assistant was at the console when
the curtain went up and the music started. Only a few minor adjustments were needed and all was
well. Again, I was amazed.
I heard clarity and articulation I had not heard previously with ‘conventional’ techniques. No barrelmidrange; the singers could move around the stage with no loss of clarity or definition; no ‘phasing’
could be heard as they moved and no obtrusive footsteps, either. Clarity, presence, balance — these
were what I heard.
Setup for coverage was simple: two PZM mics, one on either side of center stage, ten feet off-center
(twenty feet apart). The prompter’s box center stage precluded my original intention of placing three
mics across the stage but I did set two D-224’s in ‘mice’ at the extremes of the stage — for a little
‘insurance’ — but they were not needed, even though the working area of the show was over fifty feet
wide.
I had another surprise, too. Being told that the pair of D-224’s behind the conductor were in the way, I
taped my third PZM to the wall of the orchestra pit, directly behind the conductor’s head, out of sight
and out of the way. The pickup from this mic was excellent and blended smoothly and cleanly into the
overall house mix (which is mono). No problems.
As the Dell is an outdoor facility, there is a problem with wind noise. I solved this by taping a single
sheet of ElectroVoice Acoustifoam, cut to size, over the PZM. It worked perfectly.
Also, by placing a piece of heavy, black shag carpeting, doubled over, behind (down-stage) the mics,
cancellation of the orchestra into the stage mics was increased. (This technigue was demonstrated in
the April SYN-AUD-CON San Diego class with the TDS system; it showed some 10 dB of cancellation, with no appreciable effect on the high frequency response due to phasing aberrations.)
PLATE VIBRATION
Steve Durr, Nashville, TN, reports that at high dB-SPL when mounted on a stand, the 6 x 9" plate may
vibrate. If so, tape down more, or tape another piece of metal to plate with gaffer’s tape. No problem,
if the mike is on a large boundary.
PZMs ON PIANO
A. Bruce Jacobs, Fargo, ND, says:
It is the first time I have encountered a ‘non-resonancy’ close-miked piano sound. The first time we
used it was probably also the first time Peter Scheklie had been miked with one. At least, he looked
at it strangely. We were able to reassure him and also impressed his skeptical stage manager.
It would be nice to have a model with an electrostatic to-the-piano-cover hold system like the HP
plotters. (Never mind the catastrophe if the thing got unplugged during the performance.)
Thank you for making a new development available to us for such a reasonable amount of money.
Usually, some big company grabs stuff like this, gets a patent, and sells it for $500, since it is revolutionary.
From Martin Towne, Spellbound Sound, Ft. Myers, Florida: We have had terrific success using the
PZM for pickup of the piano. According to the placement technique used, we are able to get a multitude of natural piano sounds which are agreeable to (and preferred by) any listener without the need
for any equalization whatsoever. The degree of success in obtaining the desired sound (spectrum) is
directly proportional to the number of different placements tried.
PZMs AS MEASUREMENT MICS
We have been using the PZM as a measurement microphone and have become aware of its use in
solving acoustical problems. As an example, a particular church sanctuary had a measured RT60 of
approximately 4.0 sec. Placement of the PZM against the rear wall (using the PZM as the measuring
microphone) yielded an RT60 of 2.2 sec. It was deduced that the rear wall was adding 1.8 sec. of
RT60 to the room.
Calculations showed that if the rear wall had been 100% absorptive, the RT60 would have been,
indeed, 2.2 sec. I believe that the PZM was not ‘seeing’ the reflection of the sound from this wall in
this test. I believe this point may be far reaching and will aid us in identifying and quantifying problem
surfaces, more precise alignment of loudspeakers, etc.
PZMs ON INSTRUMENTS
We are studying the effects of mounting the PZM directly to surfaces of various types of musical
instruments (guitars, drums, wind and brass instruments) and will let you know the results as we
experiment.
PZMs ON ORGAN, STAGE PLAYS
Robert E. Brown, J.F.A. Electronics, Troy, NY reports that he has used the microphones successfully
to record a large Austin pipe organ in a local cathedral and also to mic a stage play for a local high
school.
Reports on the New York Metropolitan at Wolf-trap with PZM’s brought much the same response from
the sound crew as that at the Robinhood Dell.
Washington, D.C. music critics made no mention of the sound system in their reviews of the performances this past June (usually panned it before). One critic, when approached by a sound crewman,
stated, “....best sound I’ve ever heard at Wolf-trap...”
At Wolftrap, the mike was used on a piano ith lid removed. Mike was placed vertically for concealment (see sketch below).
Fig. 1. PZMs miking a piano.
Also, one PZM was placed on the proscenium for audience pickup and ambience. It replaces shotgun
mikes with 300% quality improvement.
PZM ON STRING BASS
Radio Station KLON’s “Big Band Broadcast” using PZM mikes tested a PZM-150 lavalier [discontinued] clipped inside the F hole on a string bass with low tones like the engineer had never heard before.
Our first PZM-150 lavalier will go to Tim McSwinney in Australia, who is a string bass player for recording sessions all over the world.
PZM USAGE BECOMING WORLD-WIDE
PZM’s have been shipped to Japan, Sweden, Netherlands, Australia, Hong Kong and Canada.
Figs. 2 and 3. Early models of Wahrenbrock PZMs.
PZM MEMO
December, 1979
Ken Wahrenbrock, Editor
CROWN TO MANUFACTURE PZMs
As of January 1,1980, a new manufacturer [Crown International] will produce PZM microphones for
WSA (Wahrenbrock Sound Associates). The same models will still be available. Shipment will come
from WSA.
Some cosmetic revisions are being tooled. Around April 1st, the new manufacturer will ship through
its dealers. WSA will become a dealer for PZM, and continue with the development of some new PZM
ideas. Ken will continue to edit the PZMemo to provide interchange of information about PZM to all
users.
Keep your ears open at the Winter CES show.
MORE USES FOR PZMs
ABC-TV used PZMS on piano for “All American Women.”
From BRADFORD WILLIAMS, Cerritos College:
“Several problems presented themselves from the beginning in the sound design of ‘Let’s Call the
Whole Thing Gershwin,’ a musical review now at the Westwood Playhouse. First of all, the playhouse
is not exactly acoustically perfect. It has a low reflective ceiling, brick walls, and a concave curved
back wall in front of the balcony. Secondly, the director wanted no handheld or wireless mics on stage
and particularly wanted to avoid the filtered sound so many floor miked shows have due to comb filter
effects.
Having used PZMs in college shows with success, I knew they would be the answer for this show.
The immediate problem was to make the downstage mics directional without offending the set
designer’s sensibilities with hunks of carpet. Sonex foam cut into strips and set over the PZMs with
the element just extending out the front seemed to work just fine with the side benefit of hiding the mic
from the audience as well. (See picture below)
Fig. 1. Sonex foam behind PZM on stage makes the mic directional at mid-to-high frequencies.
Upstage mic placement took a little more thought. The cast dances just about everywhere on the set,
the upstage platforms move, so it was finally decided to contact-cement two PZMs to the inside rail of
the center stairway, which turns out to be great for sound pickup and yet stays out of everyone’s way.
During the show usually just one PZM at a time is used, depending on the location of the performer.
This keeps the sound clean and minimizes floor rumble from the dancers (however, I’ve found PZMs
to be quite immune to shock and floor rumble). The mics are used only when necessary and then just
enough to keep the singers above the band. Most people are unaware that the show is being reinforced. The sound is just bigger.
As for the room’s acoustic problems, 1/3 octave EQs with pink noise were used to shape the room’s
response and then a 4 band parametric was used to control feedback.”
SUGGESTION FOR MOUNTING PZMs
Polycarbonate sheet will not crack or shatter. It is twice as expensive, $110.00 for 4’x4’xl/8". 1/4" is
not quite double that. It can be drilled, filed or sawn with standard tools.
2’x2’xl/8" works well and can be mounted on a light boom on an MS-25 stand.
4’x4’xl/8" can be suspended but single mounting of 4’x4' would require 1/4" and a heavy stand.
How about somebody testing these on a TV boom in place of shotgun mikes and then give us a report?
See illustration below.
Fig. 2. Mounting plastic sheet to a boom.
WE NEED DATA
From many of you, we hear, “PZM’s are really great. We use them all the time.”
We would like to know on what records or shows they are being used. Future PZMemos will list
them, if you give us the information.
CORNER PZM
Reproduced below is an article in the Fall 1979 Syn-Aud-Con Newsletter:
In the Anaheim class in September, FARREL BECKER, working with KEN WAHRENBROCK, proposed a new version of the PZM. Farrel’s proposal was for a corner PZM.
The PZM3 [discontinued] can be used in theatre, church or auditorium. The mikes may be made
using the natural boundaries of the lecterns or pulpits. Invisible boundaries could be developed by
using polycarbonate panels in several configurations. The side and back panels also provide attenuation to give a cardioid pattern to the microphone.
Farrel’s reasoning was that “the PZM is not affected by the reflections from the surface it is mounted
on. Therefore, if it is essentially mounted against three surfaces, as in a trihedral corner, it will not be
affected by three of the six surfaces in normally shaped rooms.”
The first illustration compares the level increase at the input of the mixer from a trihedral PZM as
compared to a regular single surface PZM. The TDS measurement is from 200 Hz to 10,000. The
upper trace is the PZM3 and the lower trace of the regular PZM. Note approximately 10 dB of gain.
Fig. 3. TDS response curves.
The second illustration is of the front-to-back ratio of the PZM3, at least 20 dB. The curves were
made by turning the back of the PZM3 toward the speaker.
Even more impressive than these measurements is the listening quality. Gain jumps up and room
influences lower dramatically. Placement of the microphone element is critical and without TDS-EFC
measurements extremely difficult to do properly.
As a system for recording conferences in small to medium sized rooms, PZM3 is without peer. Use of
the PZM3 away from large supporting surfaces merely acts as a highpass filter below the one-quarter
frequency associated with the wavelength of the plates used to form the corner mounting.
Fig. 4. PZM3.
The PZM-150 lavalier [discontinued] clipped in the string bass of the Glen Miller Orchestra picked up
so well, the vibration could be felt in the 4x4’s porch roofs around the outside pavillion at which they
were performing. (Illustration below)
Fig. 5. PZM clipped to F-hole.
PZMs ON ORCHESTRA
“Rarely does the solution to a first priority problem deal successfully with a second priority headache.
Here the PZM microphones of Wahrenbrock have not only given the best orchestral pick-up that we
have ever experienced but at the same time have provided an uncluttered visual perspective supporting the illusion of natural sound.”
PZMs ON ORCHESTRA, PIANO, HORNS, THEATER
Los Angeles Times reviews:
“...In both instances, the orchestra tended to play roughly, responding to the visiting maestro’s sometimes vague instructions with faulty entrances, ruffled textures and curious imbalances. The renovated amplification system projected all this with a primitive clarity that actually may have accentuated
the negative.”
“The 1979 sound system also brought revelations to this event. The new system - to be reported on
in detail later this month - would seem to be the removal of area microphones from crucial spots on
the stage and their replacement with general miking over the orchestra. The idea is so simple, few
have considered it.
“Tuesday, the results were pleasant - at least from the box seats below the promenade - and, you
should excuse the expression, natural. One heard the solo piano in Grieg’s A-minor Concerto without
echo or tubbiness, in aural perspective with the orchestra, and apparently without offensive electronic
boosting.”
From MICHAEL LEADER, Vancouver, B. C.:
“Tried PZM on the grand piano and sound was fantastic. Just as great on French horn and trombone.
The mic was on the control room window, 15' away from horns and sounded almost 3-D. The air from
the trombone sounded like it was coming from behind the bell.”
TOM HAYES, Krannert Center for the Performing Arts, Urbana, IL, used PZMs and a $1800 stereo
mike for 4-track “AB” of microphone pickup. A demo cassette shows transparent pickup with PZMs
and the other mike sounds like somebody partly closed the door to the performers.
PETER FRAMPTON RECORDS WITH PZMs
Modern Recording magazine interview with Tim Boyle re Peter Frampton recording of “Where Should
I Be”:
“Peter Frampton began work on (his most recent release) ‘Where Should I Be’ early in 1979 at Cherokee Studios located in Hollywood. After several months of recording with interruptions and ‘various
engineers... sort of falling through’ Frampton re-teamed with (his) long-time chief engineer Chris
Kimesy and the two moved the project to Filmways/Heider (also in Hollywood) for completion.
Tim Boyle, who seconded for Kimsey, comments on the “Where Should I Be” setup and the Frampton/
Kimsey production philosophy.
MR: How are the pianos miked?
TB: We did some interesting things. Chris took one of my suggestions, which was a nice thing. He
used two C414s for the piano - high and low end - miked close up to where the dampers are, up
towards the front of the piano, and he used a PZM (Pressure Zone Mic) plate mic, a Wahrenbrock
(Wahrenbrock Assoc., 9609 Cheddar St., Downey, CA 90242), which is a square plate pick-up mic.
It’s the first pickup mic I’ve ever heard that actually works. We used it on a couple of tunes, closing
the top of the piano, during the basic tracks especially, and covering it. So what you have is the two
mics and the plate mic taped to the lid of the piano, which is then closed.
They’re even buying a couple of those PZM mics for the road. They’re good and they’re cheap too. I
think in a couple of years people will find out about them.
So, we’ve got three tracks of piano, the plate mic and then stereo. Also, on some piano overdubs that
we did, we used the same approach. The C414s and the lid open and a distance mic, which was a
U47.
PZM CHOIR MIKING
From SOUND INVESTMENTS, Indianapolis, IN:
“Our first concern in using a PZM for a choir mike was to find a transparent material to mount the
element on so we would not have the problem of a large, ugly plate hanging from the ceiling in the
chancel area.
We found that plexiglass less than 3/4" in thickness flexed too much, and tempered safety glass
shatters when it is drilled. Then we found that untempered safety glass can be drilled and has the
rigidity we were looking for. The PZM-130 Model D element [discontinued] was removed from its plate
and mounted on a 12x14" plate of 1/4" safety glass. The plates were then hung with small gauge
brass chain from the ceiling approximately 15' from the floor, 5' on each side of center, and two feet in
front of the choir rail. (We could not use the Haas distance due to a large CFM delivery from the air
system in the choir area.) The transformers were installed in the junction box underneath the baptistry
and lines then run through the multi-cable to an equipment rack.
We found that the feedback suppressor was not needed. The signal is sent to one channel of the
main mixer for overall balance control by the operator. Only these two microphones were used to
reinforce a 90 voice choir.
In summary, we were amazed by the PZM performance as a choir reinforcement mike for:
1. Tremendous gain before feedback
2. An amazing lack of an ‘amplified sound’ of the reinforced choir typical of all other systems we’ve
heard or used
3. Pickup patterns which allow larger coverage areas with fewer feedback problems
4. The clean architectural lines we were able to obtain in the chancel area by not using the typical
‘overhead choir mike’ setup (the most important to our client).
In the same installation we used two PZM-130 Model D [now PZM-6D] microphones on the underside
of the piano lid for piano reinforcement.
All in all, both our client and ourselves are tremendously pleased with the performance of the PZM
microphones and we look forward to further use of your product.”
PZMs AT WOLF TRAP
FARREL BECKER, Wolf Trap Farm, VA reports that PZM microphones were first used at Wolf Trap at
a pre-season show called “Fairfax Family Night,” May 30, 1979. Here is a condensation of his report.
This is an annual show featuring local talent. The Fairfax Symphony (a local semi-professional orchestra) was featured for the first act. With Wolf Trap’s orchestra shell, no sound reinforcement is
required for the house but it is always necessary for the lawn seating area. Our usual procedure
consists of a single bi-directional microphone on stage directly in front of the conductor. This mic is
mixed along with two shotgun mics located on the balcony rail (with appropriate delay for each mic
location). In addition to our normal setup, we placed two PZMs on the stage floor about 10' downstage of the first chairs of the orchestra and about 20' apart.
There was no rehearsal for this show, so we started with the PZMs and proceeded carefully. The
results were hard to believe. Our artistic director, not knowing anything was being done differently,
very excitedly told the sound operator on the lawn, “It sounds like it is coming directly from the stage.”
He was referring to the quality of the sound vs the direction it seemed to be coming from.
With digital delay, we have been creating the illusion that the sound on the lawn was coming from the
stage (from a directional point of view) for many years. The PZMs brought the clarity and naturalness
to the lawn that had been missing. The shotgun pickup always sounded “muddy” and was overly
reverberant. More experimentation with the PZMS was needed, but this was an incredible improvement.
Next, we used the PZMs for a week’s run of the Metropolitan Opera. There we used the PZMs as
foot mics with excellent results. Since the Met sets up a prompters’ box center and the prompters
speak somewhat loudly, instead of 5 mics with one centered, we spaced 4 PZMs evenly along the
apron. A piece of carpet, backing side up and painted black, was placed over each mic and the entire
setup disappeared into the Met’s ground cloth.
These mics were set up about 1 1/4 hours before each performance and we were careful to mark
them appropriately so the singers could see them (also told them to beware).
The PZMs proved to be perfect for reinforcing the sound from the stage without anybody being aware
of it. No rehearsals are held with the Met either, so as the first performance began, a small amount of
high frequency rolloff was added to reduce sibilance and that was that.
With conventional mics, it was a constant battle to keep the equalization on the board adjusted for a
close to natural sound. With the PZMs, the equalization was set at the top of the first performance
and never touched again for the entire week. The sound was extremely natural and clear, with a
minimum of effort. The PZMs freed the operator to give his full concentration to the action on stage
and he had only to worry about levels. Valuable time was no longer wasted on determining how to set
the equalization for a natural sound.
The shows all went very smoothly and everyone was pleased. Even the people with the Met, who
normally listen each night, stopped listening after the first night. For the first time in six years of the
Met performing at Wolf Trap, there was no mention of sound, good or bad, in any of the reviews. This
is just what we strive for: No one should be aware that sound reinforcement is being used.
NEW MODEL
F Model [now the PZM-20R]. Flush mounting with integral phantom power interface. These are being
specified for courtroom use in several places. At the New York AES, a recording studio expressed
interest in mounting two of them in each studio for stereo pickup, talk-back or ambience. The knobs
are to reduce the chances of using the mikes for a paper clip.
HANDHELD PZM BEING TESTED
Ten prototypes of a handheld version are being fabricated and will be distributed to several users who
have indicated their willingness to test prototypes as they are conceived.
Pearl Bailey used the first prototype at a recent benefit concert and the reinforcement clarity was
exceptional. The contrast was apparent when she dislodged the mike connector in the stage floor and
a hurried replacement with a typical cardioid was made. The usual muddiness was noticeable as in
typical dynamic mikes.
PZMS USED ON THE LONG BEACH SYMPHONY
The Long Beach Symphony has an outdoor summer concert series. In July they had a PZM first, an
all-PZM-reinforced concert. They used three PZM-130s on stage front, left and right, spaced 15' apart
with one PZM” sweetener at center for reeds and harps, one PZM-150 for string bass sweetener and
one PZM left for the emcee and conductor. [Those mics are now the PZM-6D and PZM-30D].
Source: STEVE BARKE, sound engineer for the Long Beach Symphony Association.
PZMs FOR CONFERENCE MIKING
Some interesting new uses of PZMs are surfacing. A telephone company is establishing conference
rooms with speakers, mikes and hybrids to remove feedback. These are used for all kinds of service
to reduce travel costs for planning, policy discussions, etc. Previous installations required several
dynamic mikes in the ceiling to eliminate microphones on the conference tables. One PZM-D or a
PZM3 corner mike [both discontinued] will replace three dynamics with 300% improvement in articulation and great reduction in pickup of room reverberation and noise.
There will be continued experimentation for best placement of speakers and microphones for different
sizes of rooms and conference table configurations. More to be reported in the next PZMemo.
###
PZM MEMO
April, 1980
Ken Wahrenbrock, Editor
“The great end of education is to discipline rather than furnish the mind; to train it to use its powers,
rather than fill it with the accumulation of others.”
Tyron Edwards
The basic purpose of the PZMemo is to:
Train PZM users to discover the optimum uses of the PRP.
Develop exploratory mind set for what PZM might do.
Provide information on what others are finding which is helpful for a problem.
Provide examples or data on new products or products PZMs have helped produce. Serve as a forum
for ideas, questions or chuckles about PZMs and their uses.
PZMemo is a nonlinear media of the above for PRP and PZM microphones.
PRP is trademarked by E.M. Long Associates. PZM is a practical adaptation of that process and is
trademarked by Synergetic Audio Concepts.
PRESS CONFERENCE CONSUMER ELECTRONICS SHOW
Las Vegas, Nevada, January 5-7, 1980
A special press conference was held at CES on Saturday, January 5, 1980 where Max Scholfield,
President of CROWN International of Elkhart, Indiana informed the press that CROWN International
had become the newly licensed manufacturer of PZM microphones.
CROWN will assume manufacture of PZMs for Wahrenbrock Sound Associates who will continue to
distribute the microphones until CROWN has established its dealer franchises and manufactured
sufficient microphones to provide dealers with stock.
Ken Wahrenbrock is being retained by CROWN to continue research and development of PZMs. He
also will serve as editor of the PZMemo.
CROWN is initiating its manufacture of PZM with four models in black and in gold. Model B 5x6",
Model D 3x3", Model F (flush mounted) and the lavalier or tie clip version [current models are the
PZM-6D and PZM-30D].
Two power supplies or interfaces will be available:
1. A combination battery and phantom power with a transformer, and
2. An active device which converts the impedance and works on phantom power.
The target date for CROWN to have its dealers supplied is this spring (May-June).
Until that date, microphones will be available from Wahrenbrock Sound Associates.
PZM — BLUMLEIN
Three models of back-to-back PZM’s on plates, 2x2',18x24' and 1’x1' have been tested with very
interesting results. First attempts were made by using just the mikes, then reversing polarity on one
mike. The results were confused sound with lack of definition in the center. Steve Barker connected
the mikes using a sum and difference encoder at the mike and then a high level decoder for left and
right channels at the mixer with exceptional results.
Fig. 1. 2x2' matrix plate with footing for floor mounting with M-S send box.
The set is being used on KLON, Long Beach City College’s Big Band Broadcast every week with
some remarkable clarity, separation and no hole in the middle section. Investigation and testing is
continuing in a number of situations. At a recent Syn-Aud-Con seminar, the mike would pick up inaudible whispering from 10 feet on one side while conversations were being heard right at the mike. A
recording has been made using the 2x2' set on the floor in front of a brass quintet. There was excellent imaging and separation with a perfect center image as well.
Further details of the setup and interconnections will be available in the future.
Fig. 2. PZM on 12" square matrix for stand use.
PZMs ON PANELS
PZMs have been made with aluminum 6x9x4" high, 6x9x1" high, 6x6x3" high of smoked acrylic and
6x6x4" high clear acrylic.
These really provide a lot of reach on a lectern or stage position.
It would be interesting to hear what they would do on an interview situation on radio and TV.
Fig. 3. PZM3 of smoked Plexiglas.
A Model D PZM [now theSound Grabber II] on a short cable with a mercury battery holder on the
cable like that provided by Coherent Communications becomes an excellent microphone for a cassette recorder. Our lawyer is using one as he makes depositions and his secretary continually
blesses him for the clarity of the cassettes as compared to ones recorded with the mikes he previously
used. A Model 0 plate can just be placed on the coffee table and the total conversation is recorded
clearly.
A Model 0 with the bar painted white on a clear plexiglas plate for use on altars, etc. is a possibility. If
such a model would be helpful for your system designs, give us some feedback.
A number of possibilities for use with natural low end roll-off can be tested with PZMs on the clear
plastic plate for stand mounting.
Guitar pickup plus vocals ought to be clearly picked up with such a mike. Quartet pickup should be a
natural. Since there will be some difference between this and the usual quartet pickup with an omni or
cardioid, the technique of using the PZMs will have to be tested and learned.
Models have been prepared for test with 12" and 6" plastic circles.
Fig. 4. PZM with 6" plastic circle.
For more information on the PRP recording method and the use of PZM, read the article by Ed Long
in db magazine for January, 1980, p 31.
PZMs IN A CATHEDRAL
Robert E. Brown, JFA Electronics, Inc., Troy, NY, writes:
Last year, after a Don Davis pep talk, we ordered a set of PZMs with BT power supply [discontinued]
for installation in a local cathedral.
The microphones are placed in the nave, about 30 feet from the organ and choir stalls, separated by
about 30 feet from each other. As a matter of convenience, the BT supply is installed at the organ
console, necessitating microphone cables of approximately 200 ft (per microphone). Despite this
high-Z run, the only problems experienced to date involve RFI from a local radio station on isolated
occasions.
Mikes are installed with excellent results in St. Paul’s Episcopal Church, Troy, NY and Cathedral of All
Saints, Albany, NY.
PZM ON ACOUSTIC GUITAR
PZM user, Dale Kauffman, writes:
I experimented using the Model 130 Low Profile PZM [discontinued] as a pick-up on an acoustic
guitar. After trying several different locations on the guitar, I found the best location to be directly
under the strings, between the bridge and the sound hole. The Low Profile PZM was thin enough to
insert between the strings and the guitar body, yet left enough clearance so as not to interfere with the
strings or the performer.
Fig. 5. PZM on acoustic guitar.
The Low Profile PZM was mounted using thin double-sided foam tape. This gave isolation from the
guitar body yet made for easy removal. The tonal quality was exceptional and extremely clean with
very good overall response and balance.
PZM ON HORN AND PERCUSSION
Robert W. Spangler, Jr., Susquehanna Sound, Northumberland, Pennsylvania:
We’ve used the mike on several horn and percussion sessions and we love it!
PZMs IN STUDIO DESIGN
We were very pleased to receive the following (with cartoons) from Ake Eldsator, Stage & Studio,
Kungalv, Sweden:
We have done some testing with a remote-controlled hi-Z preamp (not VCA) on the studio floor and
found that undistorted peak-level could be higher compared with transformer operated units.
My own comment about the mikes is that they sound very natural and “open” but a bit overbright.
They are very sensitive to resonance and ugly reflections in the studio. The small diaphragm is very
fast, so transients sound fantastic and light-meters are always in the red area. As a studio-designer I
have used the PZM with great success to trace acoustic faults in existing studios and I look forward to
refining my own designs so that PZMs can be used without phasing on every track. In “hi-direct to
reflected energy” studios there are often sharp slaps from hard surfaces (not too well diffused) and
they are easily heard by PZMs.
SOUND-ABSORBING JACKET
If you’re very close to the mike you can hear reflections from your own body. Perhaps one can wear a
special glass-fiber jacket and cap?
Fig. 6. Sound reflections between wall and body.
Fig. 7. Sound-absorbing jacket.
Fig. 8. Flush-mounting the singer.
VARIOUS PZM APPLICATIONS
From Russ Berger, Highgrove House, Inc., Dallas:
I was very disappointed - disappointed with myself. For several years I have known of the PZMs and
read ecstatic owners’ reports of wonder and satisfaction, but never before found it in myself to move
off dead center and try them. The PZMs were put up against the finest mics Germany, America, and
Japan have to offer including Neumann’s latest and greatest, the U89.
The PZMs are clearly better.
Never before has the sound in the studio been reproduced so accurately in the control room. Now I’m
spoiled - spoiled like the other PZM owners.
One of my clients, Six Flags Over Texas, is trying a pair for their live “Gunfight Show.” They had been
using ElectroVoice 664’s with terrible results. After auditioning the PZMs over a pair of UREI 813’s,
they were amazed.
Tim Guhl, Cultural Resources Council, Syracuse, NY, says:
You were right, the PT power supply is quieter than the PXT and we’re very pleased with the PT’s. All
in all, we’re pleased with the PZM systems. We’ve been using the systems to record the Syracuse
Symphony Orchestra and the Opera Theatre of Syracuse for the past five months and we’ve never
gotten such excellent recordings. Testimony to the superiority of the new systems is born in comparison to the other miking technique that we used. Formerly, we used a Neumann SM 69 FET in a ‘midside” setup. With this we employed a woodwind sweetener mike, this to cover the swimmy image right
at the center of the mid-side configuration. We were quite pleased with the mike setup and had spent
some three years developing the technique. We even recorded a disc for New World Records and
another for Peters International with this system. Then we ordered the PZMs. The rest is history.
We first set up the PZMs to directly ‘A-B” with the mid-side system. I have never heard such a radical
change for the better! The entire acoustic of the sound changed, the mid-side setup sounded as
though we were listening to the orchestra in a small room with baffles behind our ears, the PZM systems sounded as though we were sitting in the concert hall. The image tightened and spatial localization was more accurate. The entire sound became highly detailed where it was fuzzy before and with
our very first placement there was this much improvement!
Mind you this is not just my reaction. My producer (Don Dolloff of WCNY-FM, local NPR) brought in
Christopher Keene, the Artistic Director of SSO, several of the Symphony’s musicians and the general
manager of the Symphony. I called my immediate superior, Dan Wooley, and he called the Executive
Director of our organization, Dr. Joseph Golden. We purposefully did not solicit comments from these
people to get their candid responses. The responses were all similar to my initial response. There
you have it, unqualified exaltation for the PZMs.
The PZM systems were particularly easy to use on our hall because of its acoustical equipment. The
CrouseHinds Concert Theater was acoustically designed by Russell Johnson of Consultants Collaborative and the hall features an acoustical reflector (the eyebrow) measuring 18 feet by 60 feet, suspended approximately 32 feet above the stage floor. The eyebrow extends partially over the audience
and so it was natural to stick the PZMs to the eyebrow.
We have experimented with various placements of the PZM systems and they are currently located
near the audience-most edge, spaced 18 feet apart. There seems to be an optimum pick-up angle.
As we tilted the plates toward the string sections, they became more clear and defined. As for the
glockenspiel and tambourine, I have never heard more faithfully reproduced percussion. It became
apparent through the PZMs how comb filter effect, even in close miking, can ruin the sound of microphones with good transient response. Our orchestra here moves its position on stage a great deal
and where the stereo mike needed constant readjustment, the PZMs require none. This speaks well
of observations regarding Haas effect and binural pickup, allowing the listener to integrate the sound
with his own ears. Moving to the PZMs was a giant step for us on the road toward faithfully reproduced sound.
Thank you ever so much ... for putting PZM together; as you know Thomas Edison merely put the
right materials together to create the light bulb.
PZM PRINCIPLES
Bruce Jacobs (A. Bruce Jacobs, Audio Systems Consultant, Fargo, North Dakota) raises some excellent points and questions on PZM principles.
1. The PRP articles by Ed Long carefully discuss the concept that placing the PZM on a boundary
eliminates the frequency spectrum aberrations due to interaction between the direct sound and the
major first order reflections. Why, then, put the microphone anywhere but on a major boundary? In
mid-air you will still get the first order reflections.
Let’s have some reactions.
2. Why a handheld PZM? What possible benefit in place of a conventional high quality mike?
Let’s have some reactions.
3. Eric Rudd (with Bruce), “Why shouldn’t we have the same concerns as to the placement of our
capsule in relation to plate edges as the loudspeaker designer does in placing the tweeter on a rectangular surface? The loudspeaker designer seldom puts a dome tweeter equidistant from the edges
of the cabinet much less mount it on a square surface. If he does, the comb-filter effects due to the
air impedance transition at the edge of the surface would fall on the same set of frequencies for all
four directions from the tweeter and thus would be all the more noticeable.”
Let’s have some reactions.
Further from Bruce: “In the Fall Syn-Aud-Con Newsletter, Farrel Becker says, ‘Use of the PZM3 away
from large supporting surfaces merely acts as a high-pass filter... below the one-quarter frequency
associated with the wavelengths of the plates used to form the corner mounting.’ I disagree. As Eric
Rudd helped to point out, at a low frequency where the size of the plate is small compared to a wavelength, the plate no longer serves to increase the pressure for the capsule. Instead, it lets the capsule
record the pressure as if the plate were not there. With the standard PZM, this pressure difference is
double or 6 dB.
So let’s give the PZM more credit. As the frequency drops, we reach a transition whose frequency
depends on the plate dimensions - at which point the response drops to a level that is 6 dB below the
high frequency level. Theory and measurement have not agreed for me yet as to the exact frequency
and shape of transition in relation to plate geometry.”
Let’s have some reactions.
REDUCING GLARE FROM PZM PANELS
What do you do when the PZM mounted on a 2x2' plate catches the lights when you are overhead on
a choir?
Brad Williams tilted and tilted, cleaned the plate, and moved the plate left and right. Still, light spill.
He finally painted the edge black and the spill disappeared. Is that lateral thinking?
PZMs ON COMMERCIAL RECORDINGS
Lenng Dreau
Direct-Disk Labs Nashville, Tennessee
All acoustical guitar miking is PZM.
Reflections of Dad RME1OO4
Russ Morgan Enterprises Las Vegas, Nevada
2 PZMs on drums
1 PZM on brass
1 PZM on reeds
1 PZM on piano
1 PZM on bass
The just released Beach Boys album, “Keepin’ the Summer Alive” has PZM’s on vocals and some of
the instruments.
George Burns, “Wish I was 18 Again,” PZM on strings.
New album, not yet released, Willie Nelson, PZM on piano.
Debbie Boone’s newest album, PZM on strings.
Bill Gaither Trio “Live” album at Grand Old Opry - PZM on drums.
PZMs FOR MUSICALS AND CHOIRS
CERRITOS COMMUNITY COLLEGE (Norwalk, CA) recently presented the complete Leonard
Bernstein’s Mass for six sold-out nights. The sound designer was Brad Williams, who has used PZMs
before for “Fiddler on the Roof” and “Let’s Call the Whole Thing Gershwin” (PZMemo Vol. I, No. 4, p
2).
The set for Mass is staged to represent two different environments, the temporal and the spiritual. The
spiritual is upstage, consisting of pews for a choir backed by a rose window and a cross on a platform.
The temporal part of the set was basically bare stage encompassing the downstage portion all the
way to the stairs and house aisles. To the sides and above the pews were musicians in addition to
those in the pit.
To reinforce the choral ensemble in the pews, Brad “flew” 4 PZM’s on 2’x2’x 1/4" plexiglas with the
edges painted black to reduce glare. (He found 1/8" plexiglas sagged too much in the center.) Under
normal circumstances, the choir could have been covered with 2 mikes, but the proximity of the elevated musicians on each side caused too much leakage. Four PZM’s with the two outside ones
tilted to place the backside of the plate toward the orchestra provided enough pickup for solo instruments and allowed the choir miking to be at low enough level to reduce leakage to an acceptable
level. The four mikes provided excellent balance for the choir.
The street area was miked basically with 2 PZM’s at the edge of the stage with double thicknesses of
4" Sonex to provide isolation from the orchestra in the pit. Many of the street chorus were blocked in,
to be in front of these mikes for their solos. Others moving in many areas were able to use PZMs on
wireless mikes. There were a large number of voices who had to pass a handheld wireless with
cardioid capsule.
The difference in quality was very evident. Several of the cast who were using the wireless PZMs
were amazed that they could not determine when the mike was on, since the reproduction was so
clear.
The sound system for the auditorium has a central cluster over the proscenium.
Two PZMs were also used on 4x4' masonite plates at the rear of the house for stereo reference
recordings. The director of the show was so taken with the quality of the recordings that there are
plans to edit the tapes into a cast reference album.
PZMs ON INSTRUMENTS
ANDREWS AUDIO CONSULTANTS, New York City, has used a number of PZMs for sound reinforcement and recording for vocals as well as instrumental pickup as follows:
With FLORA PURIM AIRTO, 150 handhelds on the vocals, 150 handhelds on bass drum, snare and
high hat, overhead drum set; 150-B on other percussion, 130-C on guitar amp and 130-C on trumpet
synthesizer amp comb [all since discontinued.]
With ROBERT KRAFT and IVORY COAST: 150 handheld on vocals, 130’s on piano; drums same as
above and 150 lavalier on violin.
Jesse with Dave Andrews has tested a 150 with 5x6 plate in free air on a stand for congos with as
much bass as an AKG 414, better high end, total sound was tighter and cleaner than traditional
mikes.
Dave Andrews reports that two PZMs sent to Lake Placid for the Olympics this winter stopped working; cable or capsule froze. Has anyone else had this or similar experience?
Elsewhere in this issue of PZMemo, we have published a portion of a letter and a couple of cartoons
from Ake Eldsator, Stage & Studio, Kungalv, Sweden. Ake has generously sent us his talented
sketches of a variety of PZM models and we’d like to share them with you. Here’s one of our favorites:
Fig. 9. The PZM Cap.
PZMs IN CHURCH
GARDEN GROVE UNITED METHODIST CHURCH, Garden Grove, California, has found that PZMs
really provide the pickup they desire for most of the worship services, weddings and other programs.
They are now using two lavaliers for the minister at the pulpit and altar, a PZM3 at the lectern, a PZM
handheld for other uses in the Chancel area [both mics discontinued] and a PZM on a 2x2' plate for
choir and organ pickup for their cassette ministry.
PAPERS ON PRP AND PZM AT MAY AES CONVENTION
ED LONG of E.M. Long Associates, Oakland, CA and DAVID ANDREWS of Andrews Audio Consultants, New York City will deliver papers on the development and applications of PRP and PZM in
recording and sound reinforcement.
New developments in PZM’s will be reviewed and results will be reported. Their papers will be given
at the Transducers Applications session on the afternoon of Thursday, May 8.
These are but two of the many important and interesting papers that will be presented at a jampacked
convention.
PZMs ON FLUTE, GUITAR, DRUMS, STAGE SHOWS
From Russ Berger, Highgrove House, Inc., Dallas, Texas:
The PZMs are wonderful and have solved several problems I have encountered in recording.
The PZM is the first mic that has totally captured the flute. I have tried an enormous variety of mics
and placement techniques only to find a compromise in the “essence” of the reproduced flute. The
PZM mounted approximately 1½ feet overhead on a low part of the ceiling captured the airy, icy edge
and the fluid sonority of the instrument.
The PZM works wonderfully on close miked acoustic guitar. Because of the distance-of-mic to sizeof-the-instrument relationship, standard cardioid or omni mics receive the multitude of complex wave
forms resonating off the body, sides, neck and strings of the guitar mostly off axis, producing a coloration of the sound. There is also a sizeable amount of reflected energy returned from the floor, walls,
ceiling, and off the body of the musician. This coloration determines the “personality” of the mic and is
expressed as “warm,” “smooth,” “consonant,” “rich,” “zingy,” etc.. “all them good adjectives.”
But all these descriptions are out the window with the PZM. It simply sounds like the guitar in the
room at the mic location.
So far, my favorite PZM position is mounted on the back of the hard reflective side of a 3x4' gobo at
“guitar level The gobo is approximately 2x3' away from the guitar. The sound quality is a clear, even
and accurate reproduction of the event in the studio. This same gobo works well placed some 10' to
20' (Haas distance) away from a guitar amp to achieve an open non hollow-ambient signal to be
mixed with the close mic or panned to create a delay panned effect.
The PZMs are excellent as “under heads” on a drum kit. A common problem in “over heads” is the
large proportion of cymbals compared with the toms, especially with drummers who like to “nail” the
cymbals or have them positioned exceptionally high over the rest of the kit. The PZMs placed on the
floor pick up plenty of the cymbals along with some beautiful leakage off the toms, snare and kick.
The separation and location of individual drums in the stereo spread is breathtaking. I also close-mic
the snare, toms, and kick to accentuate drop on the toms, pop in the kick and wood in the snare. This
is done after achieving a balance with the PZMs.
The PZM is being used at Six Flags Over Texas, an amusement park located in the Dallas/Ft. Worth
area.
They had a problem picking up dialogue between some 5 to 6 people staging a gun fight show. The
set is outside, located on the porch of a store front and frequently the actors move away from the
porch, out into the street. The problems are obvious, they have sought many expensive solutions to
no avail.
Two PZMs were placed on the posts of the porch and now the dialogue is plainly heard from all over
the porch and within a radius of some10' away to the front and sides. They cured the feedback and
articulation problem. These worked so well, the park has specified PZMs for several other critical
problem areas.
Ken, hopefully, someone will find this information useful as a starting place. The PZMs really do have
to be thoughtfully used. The old standard standby mic technique does not apply. I love it. It rekindles
my sense of adventure.
Cartoon courtesy of Ake Eldsator
PZMs AT ACADEMY AWARDS
Look for PZMs on the lecterns at the Academy Awards telecast April 14th. (we hope you can’t see
them!)
PZM DEMOS
CROWN will exhibit and demonstrate PZMs at:
The Midwest Acoustic Conference Chicago, Illinois - May 3, 1980
Audio Engineering Society Convention Los Angeles, California - May 6-9, 1980
Consumer Electronics Show (CES) Chicago, Illinois - June 14-18, 1980.
PZM MEMOS FOR DEALERS
If you desire additional copies of the PZM Bulletin and/or PZMemo, please request them.
We will send single copies of each with all orders we fill. If you want more copies with your multiple
orders, please so indicate.
PZMs ON STAGE
Dick Knoppow, on listening to a recording of a high school band made with PZMs, suggested that the
microphones should have been made with a velocity capsule at the plate rather than a pressure
capsule. [The music was so bad, it would be better if it were not even picked up. A velocity capsule
does not respond to pressure.]
One of the local network TV stations tested the 12" square plate on a boom in place of a 916. The
inertia, concern for light reflections, the different pickup pattern and greater sensitivity which picked up
more sound than the boom operator desired (like off-set noise) made the PZM seem too complicated
for boom use.
Some smaller models and more experimentation without great time and cost to the rehearsal operation might help discover what contribution PZM could make to TV sound.
Beverly Hills High School presented “The Music Man” and the front of the stage was covered with 2
PZM-2s while the two side areas for Marian’s Porch and Hotel Front were covered with Model C’s
[both discontinued.]
The sound system was stereo and coverage was excellent when the action was upstage or downstage. The solos were amplified with a sense of presence as though the characters were close on
mike. The most pleasant aspect was the apparent lack of microphones present.
In New York, the Metropolitan Opera is using some PZM’s on some tests to determine their feasibility
in comparison to the usual mikes and miking.
Six PZM handhelds are being tested for live concert sound reinforcement for voice and instruments at
the present time.
MORE PZM USES
From Nick Armstrong, Spectangle Productions in Hobart, Tasmania, Australia, comes the following:
I purchased two PZM model A 6"x 9" (PZM130) microphones [discontinued]. Needless to say they
were the first ones in Australia and, of course, I cannot speak too highly of them. We now do not use
any other microphones for acoustic piano. We also find them “very interesting” for acoustic guitar,
particularly in the area of upper harmonics. Two PZMs leave a crossed pair of Neumann KM84i’s “for
dead” for choir work. The presence and clarity at twenty feet from a choir is amazing to say the least.
We are considering purchasing one (or two) Model L (Lavalier) PZMs [discontinued] for use inside
acoustic guitars for studiorecording purposes. We have been using a Sony omni-directional (ECM50P5) Electret Condenser mic hung inside the acoustic guitars with some success. The main advantage over conventional close front ‘miking’ is a high rejection from spill from other close high level
acoustic instruments, such as a drum kit....
###
PZM MEMO
SPECIAL EDITION
1980
The following quotations are the result of a recent survey from PZM users.
“A mic capable of recording an entire choir or symphony orchestra. All my students - I’m a drumset
instructor - asked me what the object Neil Peart had taped to his chest was in a recent Rush video. It
turned out to be the PZM used on the Vital Signs out of their recent album Moving Pictures. Spectacular drum sound.”
Russet Scarborough
Norfolk, Virginia
“They are really far-out. I really dig the way they pick up all these mat sounds. (just kidding) I think
they are outstanding microphones. I have seen a lot of these microphones being used in all type of
applications. Keep up the good work.”
William Dike Goldenrod
Florida
“Recently I recorded my drums in my amateur studio. I tried using a PZM mike for an overall drum
track. I was using a 4-track recorder and, with limited time, was trying to get a full sound with one take
on one track. I found the PZM to give a complete sound with a rich ambient sound which was exactly
what I was looking for.”
Mark W Meana, Jenison, Michigan
“They work where conventional mics don’t - the pickup range is greater without use of special tricks.”
Bob Andrews, Tempe, Arizona
“It’s appearance FLAT - brings to mind a description: F for fine - like a musical instrument. L = Live - in
its performance, and 1:1 reproduction of sound. A = affordable, when you consider the high price of
pro mics; this one can do the job of many multi-mic systems. T = Timely: a perfect mic for digital
recording, and its demands for a microphone which can withstand high SPL. It can only stand to
reason it will testify to its versatility for time to come.”
Timothy J. Wurgo, Fort Worth, Texas
“The performance of the PZM never ceases to amaze me. In my 41 years of experience in the sound
and communication industry I have not seen a microphone that has impressed me as much as the
PZM.”
Wayne C. Stephan, Opr. Mgr Ohio Valley Communications, Inc., Evansville, Indiana
“I engineer in a small studio where we have to take advantage of all the ambience we can. PZMs
always work. They are everything from beautiful on a piano to awesome on a drum kit. Whether I’m
using a PZM as a close mic or a room mic I know I can count on it for sounds that my clients are
looking for.”
Karen Hing, Arvada, Colorado
“PZM microphones maintain greater fidelity in their pick-up than do conventional microphones. This is
due to phasing at the point-of-pickup of the microphone. Because of close tolerances between a
reflective plane and the pick-up point, secondary signals arrive in time very close to the prime signal,
which allows the phase amongst the signals to be much closer. This results in a much ‘cleaner’ sound
to the listener.”
Marc H. Danforth, Orlando, Florida
“Wonderful in stereo pairs, in close and at distance on: Acoustic Piano, Rhodes Piano, Drums full kit
and with one in kick, Acoustic guitar, Electric guitar for space. Recently used exclusively on regional
promo for an ad agency, again a stereo pair for flute, flugelhorn, drum overhead, no EQ, client was
EXTREMELY pleased, as were musicians, for the effortless, airy, natural sound. Still continuing to
experiment - oh, almost forgot, again excellent for stereo percussion. Essentially we set them up as a
sound field, and have the musician play in the space between them. Very convincing! Expect another
entry from us for the PZM contest this year.”
Alfred B. Brunwell, Calf Audio Inc., Ithaca, New York
“Excellent for many speech applications because of the accuracy and high articulation. I’ve compared
the PZM with $2000 Neumanns, Sony ECM 50’s, and other professional microphones. Compared to
the PZM, they appear to have the talker with his hand in front of his mouth while he’s speaking.”
Mario V Maltese, Williston Park, New York
“PZMs are the answer to many formerly ‘gray’ areas for miking applications, instead of having to
compromise your application with some mic really intended for some other use. I have used PZMs for
everything from picking up a choir in a church, to hidden applications for consumer comments on
filmed marketing research application. Thank you Crown.”
Dan F. Mccurdy, Garland, Texas
“We have mounted a PZM-6LP [now the PZM-6D] on a piece of plexi and it works just great when the
students use it for their dramatic assignments. The hemispheric pickup pattern of these mics are just
great allowing for no audible gain change as the talent moves from stage right to left. We have done
several dramatic plots that have used PZMs and the audiences have been shocked. Extremely even
pick up even at 25 ft.! Unlike my SM-57 which exhibit very uni-directional properties.”
“I have used the PZMs since they were introduced, and I always find it fun to tell students that ‘this
small mic is positively a milestone in theater reinforcement and recording.’ They don’t believe me till
they play with them and you should see the expressions!! I use our PZM-3OGP [now the PZM-30D]
for an orchestra pit when we do musicals - use a little type II DBX resurrection and bingo! Perfect
repro.
Robert Steven Yablans, Denver, Colorado
“A PZM has a hemispherical pickup pattern and unbelievable sensitivity. The PZM has opened up a
world of new miking techniques. In order to believe in the PZM you have to use it.”
Tim Tison, Evansville, Indiana
“We own several PZM-30G’s [now the PZM-30D] in our rental department. Recently, our mobile 24track truck was contracted by CBS Television to provide the mics for the 1982 Grammy Awards Presentations. Our position of the show was the ‘Willle Nelson’ insertion, originated live from his concert
that evening in Huntsville, Texas. We used a single 3OGPB, mounted to the front lighting tower for
audience reaction. The PZM’s work very well for crowd noise, due to their pattern, and because of
their very ‘open’ and ‘airy’ sound. Also, I have noticed that the PZM series is very forgiving around
‘dirty’ power and ‘buzzing’ lighting equipment. Of all the microphones we used for the event, only the
PZM was completely free of noise and hum.”
Mike Simpson, MIDCOM, Inc., Arlington, Texas
“Excellent mic. The PZM is the most natural clear microphone out today. Applying it to use on plays
produces an amazing clarity and depth. I think one needs to use less gain for this mic. The sound may
be deceiving. Even though there may be less SPLs coming from the speaker, intelligibility comes
through loud and clear.”
David L. Ediger, Tigard, Oregon
“PZM eliminates commonly found phase cancellations inherent to conventional microphone designs
by creating a pressure zone in the small gap between the microphone element and its mounting plate.
This pressure zone minimizes the direct to reverberant waves differential and results in smoother
more natural reproduction. This is accomplished by a pickup pattern of 180 degrees hemispherical
and results in very even off-axis frequency response. I recommend these mics highly for many but not
all applications.”
Michael H. Webb, Huntington, W. Virginia
“PZM microphones are simply amazing! I have used a pair of PZMs mounted on 2' x 2' acrylic sheets
for area miking. I used this miking arrangement on tall stands to mike a swing choir outdoors. Even
though it was an exceptionally windy day, the PZMs performed very well and did not pick up any
noticeable wind noise. They are just incredible.”
Brian Haynie, Portland, Oregon
“I find the PZM to be a very useful tool. On a grand piano, it causes the quality of tone and clarity to
come alive. I have had excellent results in this application. Placing a PZM on a music stand in front of
trombones or trumpets creates a very solid and excellent sound.”
John D. Alexander, Anchorage, Alaska
“Fox Music, Charleston, S.C. loaned us one to mike the orchestra of a local opera production. It was
sensational. We used one mic on a plexiglas sheet mounted on a music stand and it (the PZM) did the
job of at least 3 other low impedance mics we would have used. I also used it for a video freelance
news story later broadcast.”
William B. Reed II, Charleston, South Carolina
“They do not introduce axial variations in sound level. These mics also are terrific for large sound level
areas since the sensing element can handle large SPL levels (150 dB). These mikes are extremely
sensitive even up to 30 - 50 feet from them. PZM mics react in much the same manner as our ears
do; making placement in the sound area less complicated. It’s great for ‘true to life’ live recording.”
Robert L. Gilbert, Wichita, Kansas
“I have used your Crown Pressure Zone Microphone (PZM) on various miking techniques. The PZM
sounds exceptionally bright on pianos and brass instruments. The sensitivity and directivity still astound me even though I use it a lot.”
Lisa Orti, Denver, Colorado
“I bought the PZM-2LV for our church. It is used for sound reinforcement and recording. Its main use
is a lavalier mic. But I have also used it to mike our choir by placing the PZM on a solid wood railing in
front of the choir. It has also been used to mike our grand pianQ. This PZM does a very good job for
all three uses. I chose this mic for its size, the natural sound it reproduced and because it can be used
with phantom power. (No batteries to replace.)”
Donald C. Nieherh, Denver, Colorado
“Being a newcomer to the PZM mics, I am not too accurate on how to explain the PZMs. But having
used a PZM mic set-up to record a friend’s band with my own home equipment which consists of a
Crown PL2, a Crown SL2, Revox B77 MK II, and borrowing some mixing boards, I was overwhelmed
after the mix-down at the fantastic sound of the PZM, considering I am no expert at mic placement.
Keep up the great work.”
Charles W. Patterson, Dundalk, Maryland
“Record Production: Used for environmental sounds on pop record - unusual imaging realism. Used to
record woodwind instruments without the usual ‘hot spot’ effect found on saxes and clarinets when
close miking. Live Sound Mixing: (Harry Belafonte) excellent inside miking of acoustic piano with lid
closed without experiencing sound-board ringing.”
Bob Burnham, Boulder, Colorado
“I find the PZM very useful mounted on a large boundary, facing the group for general ensemble
recording.”
Tony Kralik, Omaha, Nebraska
“I’ve used the PZM microphones in churches (on pianos) and the full sound I get is amazing and so
inconspicuous. I’ve interfaced the LV Series with some Con-Tek wireless gear and the results keep
amazing me. The PZM microphone fits in so many situations instead of a conventional type mic with
increased fidelity. Don’t stop making them.”
Ken M. Blecher, Total Design Communication, Boca Raton, Florida
“Possibly the best innovation in microphone design yet. The PZM works when many other quality mics
just won’t do the job. Many people are skeptical when they see the mic but after hearing what it can
do they are always impressed.”
Peter Franks, Omaha, Nebrasha
“I tried miking my piano by using a single PZM on the floor directly underneath and used carpet
around the sides of the piano for isolation and got the best sounding recording of my piano that I ever
heard!”
Benjamin J. Castle, Atlanta, Georgia
“I am in a local band and once when we were in the studio and couldn’t get a good sound out of our
Marshalls, we used a PZM. This worked out great. Keep up the good work.”
Doug Grant, Billy’s Band Aid, Lubbock, Texas
“Fantastic for use with pianos.
Paul 0. Abbott, Charles Christopher, Spokane, Washington Winter Park, Florida
“Recordings done with PZM far better than those done with other mics.”
Linda Westbrook, Lewisville, Texas
“Very nice for most about anything in the studio. Drums, vocal, piano, you name it! I’ve also had good
luck using them for sound reinforcement for dramatic productions. They seem to have a realistic,
natural sound on almost any instrument.”
Paul Thompson, Kettering, Ohio
“I play in a R & R band in Wichita and we record every gig. I use the Crown PZM-3OGPB by itself to
record with. With proper mic placement, this is the only way to go. Great recordings every time. Keep
up the good work.”
Cortis R. Payne, Wichita, Kansas
“Super mics that will do the job when others won’t. Sensitivity is excellent.”
Jack Thucler, Grand Rapids, Michigan
“The PZM microphone is mounted on a flat surface acting as a pressure zone, or sounding board, for
the mic, making it very sensitive to low frequencies as well as high frequency sounds. Therefore, it
sets off the good acoustic designs of some music halls, and exposes the poor acoustic designs of
others. The mic works well as either an ambience or direct mic, and has a sensitive hemispherical
pick-up. The PZM is an unobtrusive mic and can be easily hidden. It is a durable microphone, resisting many casing shocks during performances. Also, it will transmit sounds up to 150 dB with no distortion. which is remarkable. On top of all this, it has an excellent reach of thirty feet. All in all, the PZM is
a technologically advanced microphone that will surely attain great popularity.”
Michael S. Reese, Dallas, Texas
“Recording vocal groups (church, etc.) is achieved easier with PZM than conventional mics.”
Jim Bell, Springdale, Arizona
“Excellent stereo imaging when used in wind ensemble/symphony application. Impressive results on
all percussion instruments. Amazing headroom - absolutely noiseless.”
David K. Castell, Westbrook Audio, Inc., Dallas, Texas
“They make good choir microphones.”
Jim Pearce, Wichitaw, Kansas
“I have had great success using the PZM for difficult-to-record instruments such as the usual un-DBX
or Dolbyable problem children. Most recently the PZM functioned very satisfactorily on an ornamental
candle stand that was part of an old pump organ. This, coupled with a ceiling ambience AKG224,
gave very good reproduction and great rejection of the pump-pedal noise. The use of the PZM as a
center ambient mic behind (+ 3 feet above floor level) vibraphone solved a 3 year problem.”
T. Hartley Severns, Cambridge, Massachusetts
“The PZM has a calibrated electret capsule which is mounted to a parallel acoustic boundary plate.
This allows the incident and reflected waves to be in phase when reaching the transducer. Within the
pressure zone, there is no comb filter effect, which can be caused from out-of-phase sine waves. I’ve
used the PZM as an overhead on the drum kit and also on bass amps and guitar amps and have had
very good response!”
“We have been using PZM microphones for almost 2 years now, and each time, I am still amazed and
in fact excited by the quality of the sound. We use ours for sound reinforcement and it has made our
jobs a lot easier and in fact has made us sound better than ever before possible. Thanks for a real
problem solver. The PZM is a true piece of professional equipment.”
William H. Stewart, Richfield Properties, Richfield, Ohio
“Gives me all the headroom I need on piano miking without feedback.”
Blanca Soler, Portland, Oregon
“I have strapped a PZM-3OGP [now the PZM-30D] with rubberbands to the air holes of a standup
bass so that the plate is just slightly off axis of the string (just above the bridge). It was a very noncolored sound but the bowing action was seemingly accented. As long as the rubberbands didn’t pop
off during a live performance it worked just fine. Mounting them on plexiglas for a large surface for
choirs and drama usually works well. If you need a lot of gain, an equalizer is helpful especially for the
extended bass response that the larger plate creates. But it does remain quite natural sounding as
compared to other condensers. (A-B test with SM81 and C451) It sounds acoustically louder, rather
than electronically louder; as if the room was getting more live, not the system getting louder. Quite
nice.
J.B. Merrell, Thisa, Oklahoma
“Our company has installed PZMs in churches, conference rooms and small studios. When using the
right PZM and proper installation, we’ve received nothing but praise. We have experienced no service
problems and no failures. For the money, there’s nothing better.”
Gary L. Russell, Service Mgr. Pamgon Music Center, Tampa, Florida
“The PZM has proved to be most effective stage miking for theatre. The PZM is a proven winner for
choir miking and ambience recording.”
David Schultz, Tulsa, Oklahoma
“PZM microphones are based on the pressure zone principle of microphone pick-up (a tiny transducer
mounted to a reflective plate to pick up reflected sound waves). For this reason, any hard reflective
surface on which the PZM is placed becomes a pressure zone. This has several advantages: increased pick-up coverage, increased gain, unlimited mounting possibilities, virtually eliminated phase
cancellation experienced with normal microphones. The PZM also has a hemispherical pickup pattern,
which makes it ideal for applications where suspended microphone mounting is preferred (choirs,
plays, orchestras, recording, etc.) The PZM’s even response and clarity make it an ideal microphone
for general purpose applications. It reduces muddiness and increases intelligibility in all voice applications.”
Dave G. Arrington, Cuyahoga Falls, Ohio
“I know from past experience that no one microphone can do it all, including the PZM. What I do know
is that the PZM, opened up a whole new era in relation to its unique design, and quite frankly I’m
impressed:”
Pat Lopez, Laredo, Texas
“PZMs changed a lot of engineers’ minds about recording by opening a new door in the usage of
microphones and mic placement. PZM also solved a few of the many difficult problems in live reinforcement in the area of choirs especially. I just think they’re great.”
Michelle Moriarty, Robert Kosloskie
Golden, Colorado, Billy’s Band Aid, Lubbock, Texas
“Crown PZM microphones consistently give us astounding results as ‘footlight’ mics, altar mics, pulpit
mics, ambience mics, lavalier ... but I thought everyone knew that! One church bought a PZM mic for
their pulpit even though it cost more than the rest of their sound system because it enabled them to
understand the ‘spoken word’, What more can I say???”
Philip B. Clark, Diversified Concepts, Inc., Marcellus, New York
“In my 11 years experience in the fields of sound reinforcement and recording, the Crown PZM microphone has been a mic of many firsts: The first fundamentally new design concept. The first mic to do
a good job covering a stage. The first time I’ve recorded a piano that sounded like a piano. In short,
while the PZM microphone by Crown cannot do every job, there are now some jobs that nothing else
will do.”
Jim Carlon, Des Moines, Iowa
“In recording of traditional music, which usually takes place in the environment of the performer
(kitchen, parlor, etc.) the PZM adds authenticity to the recordings by accurately capturing the ambience the music was, and is, heard in the most.”
Gregg Lamping, Fort Lauderdale, Florida
“This particular Crown PZM microphone works very well as a drum set overhead. Drum and cymbal
miking has only recently gotten much technical attention. The development of this type of broad range
microphone is the type of breakthrough that is really needed to pick up the overall sound of such a
large acoustic instrument. Thanks to the people at Crown, keep up the good work.”
Joseph E. Kane, Honolulu, Hawaii
“One thing that works well for me when miking acoustic piano with PZMs placed on the under-side of
the open top: hanging fairly loose-weave cloth from the top to cover the opening down the long side. If
it’s blade cloth it doesn’t look bad for a live gig, and it doesn’t cut down on sound projection from the
piano. But it sure reduces extraneous noise from making it to the PZMs. Hope it works for you.”
Everett W. Armstrong, Ann Arbor, Michigan
“Applications in the studio - great for close miking vocals and pianos. I’ve also used them for ambientmiking Marshall stacks in concrete rooms.”
Andrew D. Canulette III, Newberg, Oregon
“It doesn’t lie. If ‘it’ sounds good (or bad) with a PZM, odds are that ‘it’ sounds good (or bad) to begin
with.”
Bruce Coffman, Houston, Texas
“They are unsurpassed for miking choirs, theater dramas, etc. They have excellent pick-up characteristics, even from a good distance, without loss of tone. They can be mounted on a flat surface, such
as plexiglas, for even greater sensitivity. I choose the PZMs simply because it worked better than any
other microphone for my purposes.”
Jim Atchison, Fort Smith, Arkansas
“They have been excellent for stage pickup microphones, which has been a problem we have been
running into for years.”
Marc C. VanderLinden, Audio Com, Inc., Des Moines, Iowa
“The PZM picks up the sound closer to what the ear hears than any other microphone. The Crown
PZM is good for recording the ambient sound in a room when recording sound effects, or small acoustic musical groups, is also very useful in the theatre when a sensitive slim line mic is required.”
John Cooper, Masque Sound, New York, New York
“I own a small sound company in the Denver-Metro area. Since the acquisition of my first PZM, a
3OGPB, I’ve had opportunities to use it in many of the applications mentioned in the owner’s manual.
It works beautifully for conference reinforcement and recording, piano reinforcement and recording,
etc. It is used most often for overhead drum miking in rock and jazz sound reinforcement. I use a
sheet of 4' x 4' plexiglas suspended directly above the drum kit, the front being slightly lower than the
back. It is impractical ‘cosmetically’ to use even a 2' x 2' boundary in front of the drums, and the lower
toms do not sound natural when the PZM is suspended on a boom by itself.”
“The PZM, excluding the price, would make the perfect dictaphone recorder for the executive who
likes to walk around his office as he thinks out loud. Mounted inconspicuously in the same executive’s
desk, it could be used for taping in the office meetings, etc. I have also used it for ‘surveillance’ in my
home.”
Ronald A. Botsho, President, Evenstar Productions, Inc., Lakewood, Colorado
[Editor’s Note: Now we have the PZM Sound Grabber just for that reason.]
“Pressure Zone Microphone. Reach and clarity are improved. One or two PZM mics can do the job of
six to eight conventional mics. PZM mics sound very natural.”
Scott T. Smith, Odessa, Florida
“I find the Crown PZM microphone to be an outstanding tool for sound reinforcement in a theatre.
We’ve found it extremely effective when hung on a stage border at picking up all sounds upstage,
which has always been a problem. The PZM has made it easy for me to satisfy any customer regardless of how difficult a situation they are in.
Joseph R. Bosnack, Jr., Central Islip, New York
“They work all the time. For stage and theater simply adhere to plastic and fly above stage. It’s goof
proof.”
Lance M. Fisher, Fayetteville, New York
“In doing classical pipe organ recordings, often the frequencies above 8 kHz are lost or dimished by
the time they reach the microphone. This is especially apparent in dry or dead rooms. By using the
PZM-3OGP [now the PZM-30D] at medium distances (30-50 feet from the sound source), high frequencies are restored due to its high-end boost. This also eliminates the need for spot reinforcement
mics close to the sound source, giving greater presence and a less confused stereo image in the mix
due to the use of fewer mics.”
Frederick M. Mobman, Pro Organo Radio Series, Morris, New York
“PZM microphones eliminate many problems, but they do not introduce new ones; the perfect combination of properties. Thanks for that!”
W. Bulthuis, Ensehede, Holland
“I started using PZMs about 3 years ago. At first we had a lot of resistance from musicians accompanying us to use the PZM because most of our shows are festivals with no rehearsals. Once a group
has used the PZM, there’s no turning back. We have found it SUPER for both recording and sound
reinforcement.”
Greg Morrison, Dan Furney, Dallas Texas Toledo, Ohio
###
PZM MEMO
Sept. 1980
Ken Wahrenbrock, Senior Editor
PZM MODELS NOW AVAILABLE FROM CROWN
The PZM microphones have now been re-engineered at Crown for quantity production, and in the
process have undergone quite a face lift. They are handsome looking products!
Two models, in a choice of black or gold, are now available; and two more are moving towards an
early release date.
Crown Model 3OGP [now PZM-30D] is designed as a general purpose PZM with a 5 x6 inch plate and
an XLR connector.
Fig. 1. Crown PZM-30GP
Crown Model 6LP [now the PZM-6D] is a smaller PZM with a 2 x 3 inch plate and an XLR connector
at the end of a cable. The 6LP is suitable for all applications but is most useful where minimum size
may be required for aesthetic or practical reasons.
Fig. 2. Crown PZM-6LP
Crown Model 2LV [discontinued] is a lavalier or clip-on PZM and will be available from production
about January 1, 1981.
Crown Model 2ORM [now the PZM-20RG] is intended for recessed mounting, with the XLR connector
beneath the plate. Small stubs surround the cantilever to prevent sheets of paper from slipping underneath the transducer. This model is now in R&D and will be handled on a special order basis. This
special order policy will continue until demand for the model increases. Also available from Crown are
two power supplies for the PZM system, an active (PA-18), and a transformer (PX-18) version [discontinued]. Both versions can be used in phantom or battery modes.
CROWN TO MANUFACTURE AND MARKET PZMs
Wahrenbrock as Consultant
In order to be able to devote more of his energies to new product development and to assure the
production of high quality PZMicrophones at a rate needed to satisfy demand, Ken Wahrenbrock, the
developer of the PZM, has assigned manufacturing and marketing of the microphones to Crown
International, Inc., the world-renowned manufacturer of quality audio components for professional and
home use.
Wahrenbrock will work closely with the Crown R&D department on new product development and with
marketing in suggesting solutions for user problems encountered in the proper use of PZM microphones.
As part of this total effort on Crown’s part, the preparation and publication of the PZMemo will become
the responsibility of the Crown marketing department, working under Ken Wahrenbrock’s direction as
Senior Editor.
Franchises for the distribution of PZM microphones are now being assigned by Crown to professional
audio dealers around the world. A list of those dealers will appear in an early issue of PZMemo.
Fig. 3. Ken Wahrenbrock, Max Schofield, R. David McLaughlin
VIRGIL FOX AT WOLF TRAP
The huge Allen organ that Virgil Fox uses has more than 160 speakers distributed around the stage.
As the sound reached the grass area, it was reinforced by time delay fed by two PZMs on the
proscenium. Each rank stood out with great clarity as it was used. One could move from grass to
balcony or under the balcony and move from one sound field to another smoothly without noticeable
change. The boundary was only discernible if one listened very critically.
As a closing, a soloist from Riverside Church in New York City sang “The Star Spangled Banner” into
a 2" square plate on a low stand without any briefing and was quite unsure of how she was being
miked. No problem with pickup or clarity.
“MUSIC MAN” AND PZM
The Downey (California) Civic Light Opera presented fifteen performances of “Music Man” in June and
all microphones were PZM. The director, musical director, cast and technical crew were amazed at the
improvement over past sound coverage of their productions.
Consistently good reports were received during the run from visitors from other areas who are involved in their own productions. Enthusiastic approval for the clarity of dialogue and solos was ex-
pressed by many involved in theater in other areas who visited the production. A drama teacher who
expressed concern about the production before hearing the performance, brought her entire class 150
miles to see the second performance.
Several new models of PZM were tested on this production. The 2-1/2 and the pyramid models, using
1/4" Plexiglas were able to provide reach for dialogue and solos 15' to 20' upstage. The pyramid was
flown behind a border further upstage and covered the upstage action with great clarity.
Fig. 4. PZM pyramid hung over the stage.
Two PZM3, two PZM2, four PZM 2-1/2, one pyramid and one L model were used. The wireless mike
was used for Marian’s dialogue upstage. Coverage included two side stages as well as the main
stage. Five PZMs covered the stage-front to avoid loss as cast moved about the stage for dialogue
and solos.
“YOU CAN HEAR THE DIFFERENCE”
FARREL BECKER was idly watching TV not long ago and caught Victor Borge on NBC. The red LED
went on, “That piano sounds different!” He connected his hi-fl to the TV set and listened and confirmed his impression. As he examined the piano carefully, he could see the PZM on the lid. He and I
firmly believe that when you listen to PZMs, DICK HEYSER’S Catastrophe Effect takes place and you
can hear the difference. I have heard the same on several records but haven’t been able to get the
confirmation from the record producer yet.
PZMs ON COMMERCIAL RECORDINGS
“RIGHT TRACK”/Dale Ashby and Father
Gryphon Label G918
Artist is Cy Coleman Trio
PZM on piano and studio ambience
Gryphon Label
Artist is Mel Torme
PZM used for audience response
“THEY ALL LAUGHED”
Country Western movie now in production
PZM used for audience pickup and reaction
National Public Radio Broadcast from Avery Fisher Hall
“BLUES SHE’S A LADY”
PZMs on floor for program pickup
PZMs IN NEW YORK
Dave Andrews, “the world’s greatest PZM salesman,” has been using PZM hand-helds in a number of
recording and reinforcement applications. Among them are:
Funk Rock
Roy Buchanan
Dixie Dregs of Atlanta, Georgia
Nancy Wilson in Avery Fisher Hall
Michael Franks-Town Hall, NYC
Concert in Carnegie Hall
RKO Radio in New York City is using PZM for interviews, picking up the interviewer and the interviewee on the same mike.
CBS, New York City, now has sixteen PZMs for a wide variety of applications.
PZM AND TONY ORLANDO
STEVE OLIKER, Tony’s sound engineer, tested PZM-L’s on the orchestra string section by clipping
the L’s (lavaliers) to the strings between the bridge and the tail piece. The sound was magnificent,
according to Tony and Steve, with little trouble from stage monitors. However, musicians seem to
have little concern for care of microphones and the L’s will have to be more rugged to withstand the
less careful handling. A Model D was taped inside the body of the harp to amplify the instrument
without feedback from monitors and reduce the finger and strumming sound. Again, the response was
enthusiastic.
A Model L was clipped to the percussionist so he could carry his mike from vibraharp to bells, to
drums, etc. It needs more boundary to do the job but more experimentation is planned.
NBC SPORTS are ordering PZMs for their presentations this fall.
HOW TO USE PZMs?
Most of the questions that are raised about the varied uses of PZMs are the result of many experiences with traditional microphones and the sometimes difficulty in re-orienting to a new pattern of
thinking about microphone techniques and placements. There has developed a rich bibliography of
microphone techniques and many engineers have discovered particular placements and methods that
provide the exact sound they desire. It may be that a different and perhaps new mindset is important
when considering the uses and methodology of PZMicrophony.
An excellent resource for your consideration is “The Pressure Recording Process” by Edward Long
and Ron Wickersham. Available from Ed Long, E. M. Long & Associates, 4107 Oakmore Road, Oakland, California 94602.
PZMs HORIZONTAL OR VERTICAL??
Dennis Badke of CROWN raises questions about points covered earlier on the position of the plate.
If the plate is placed so the source is 90 degrees from the plate, the pressure zone will be stronger;
however, it will also be affected by any reflected sounds from floor or walls that reach it, so as to
create comb filters. If the plate is placed on a horizontal boundary and the source is closer to 0 degrees, so that pressure zone is developed all along the boundary from the source to the microphone,
the pressure zone may be less; but the effect of reflected sound will be less also, and thus the resultant signal from the microphone will be a more faithful reproduction.
When using the PZM2, PZM2-1/2, and PZM3, one must remember that unless the areas of each
boundary are equal there will be a different frequency response for each boundary and thesummation
of the zones will provide a roll-off or accentuation of frequencies.
If a PZM3 is placed in one corner of a room with walls of a fair order of smoothness, frequency response will be excellent and the ambience reflections of the three walls will be canceled from the
pickup of the microphone.
Experience of placing PZMs downstage in front of symphony orchestras reveals that the sound pressure of the woodwind sections is sufficient to provide excellent pickup for either recording or reinforcement, even though they are 20' upstage.
FLUSH MOUNTING RAISES OUTPUT
ALAN H. LUBELL explains why flush mounting of microphones raises the output by 6dB rather than
3dB:
“Pressure doubles at a hard boundary and particle velocity doubles at a soft boundary. Both of
these effects are standard results in boundary value problems in acoustics due to the coherent
addition of incident and reflected waves right at the boundary.”
STAND-MOUNTED 4’X4' PLATES
LEROY SHYNE of Shyne Sound, San Rafael, CA, mounted some 4’x4' sheets of Plexiglas on 15'
stands for overhead PZM pickup of orchestra and choral groups with exceptionally clear reception.
He also used one of the plates with PZMs on both sides of the plate for vocal overdubs in the studio.
He mounted the plates on the ceiling of his studio with PZMs for vocals and some extra special conga
drum tracks. In one sound reinforcement gig, he mounted a PZM inside the piano on the vertical side
of the piano for excellent piano reproduction.
THE KNOPPOW SUGGESTION
If you missed the point of using a velocity capsule for the high school band recording (April ’80
PZMemo), a PZM with a velocity capsule should be an interesting device when pressure is high,
velocity is zero, etc. Dick didn’t elaborate about the phase shift, but we got the point.
BACK-TO-BACK PZMs ON A PANEL
CLAY BARCLAY has used back-to-back PZM’s on several sized plates for stereo recording without
using any matrix; and in carefully controlled playback, he feels there is no loss of the center image.
In several emergencies when making recordings at the last moment, he has separated the PZM’s as
much as 60' and made recordings that are crisp and exciting to listen to.
The PZM’s should be in polarity and back-to-back.
PZM WEDGE FOR STEREO RECORDING
EVAN WILLIAMS at Golden West College has been checking such stereo recording and feels that to
separate the PZM’s about 7" by placing them on two plates in a V with the apex toward the source will
provide a fuller center image. Such an arrangement should be spaced so that the capsules are at the
junction of the vertical and horizontal boundary or high enough to avoid comb filters from direct sound
and reflections from the floor.
PZM LAVALIER USES
Excellent clarity is achieved with a PZM Lavalier-tie clip even when placed under the tie or clothing.
Other uses suggesting themselves are: PZMs on movable scenery when close miking is important;
close miking for groups when there is no place for cables. [The current model is the GLM-100.]
NEW MODEL PZM2-1/2 AND PYRAMID FOR THEATERS
BRAD WILLIAMS of Cerritos College, California, with some of his crew, were brainstorming to solve
sound pickup problems for their theatrical efforts. They had tested PZM and PZM2, so deduced that
something in between might provide some excellent coverage yet some more discrimination from
orchestra pickup. They decided to test 135 degrees angled panels and made up several prototypes of
PZM 2.5’s [now replaced by the PCC-160]. In test, they do an excellent job.
Several weeks later, the same team also sought to improve on the 2' square plate for overhead miking
of drama for state or closed circuit TV and calculated the angles required to make a pyramid. Three or
four prototypes have been assembled and used in several applications. Some of each of these will be
provided for testing by the prototype team this summer.
A new model semi-parabola 12" in diameter has been assembled. If will be tested at a Syn-Aud-Con
seminar; and if a workable coverage pattern is measured, additional test models will be sent to the
prototype test group.
Fig. 5. PZM 2.5
CONFERENCE TABLE USE OF PZM, PRESSURE ZONE SPEAKER AND
SBA
Several experimental models of pressure zone speakers with pressure zone microphones mounted
above in the sound-canceling focus with the speakers powered by signal biasing amplifiers are being
tested for a much simplified module for conference tables in many different applications. Such a system with automatic mixers and signal-biasing amplification equipment will require very little rack space
for electronics and provide a pleasing and efficient module for the table in a wide variety of uses.
Fig. 6. Pressure Zone speaker and SBA
PZM3
DEWARD and KALE TIMOTHY of Poll Sound, Salt Lake City designed a different version of the
PZM3 for use on pulpits and lecterns. The acoustic response is good and the physical dimensions
satisfy the aesthetic.
TO THINK ABOUT
Several reports have popped up that interesting things begin to happen when touring groups arrive at
a theater and the house soundman suggests using PZM. More and more traveling soundmen have
heard of them, not yet had a chance to try them and are really interested in seeing what they will do.
PAPERS ON PZM AT AES, NYC
DAVE ANDREWS and KEN WAHRENBROCK are going to present papers on the use of Pressure
Zone Microphones in two sessions at the upcoming Audio Engineering Society convention in New
York City. In Hans Schmidt’s session on Broadcast Audio Update, the paper will be “Pressure Zone
Microphone Techniques for Broadcast and Television” “The Use of Pressure Zone Microphones in
Theater Sound Reinforcement and Recording” will be presented in Cecil Cable’s session on Sound
Reinforcement and Acoustics.
The AES Convention in New York will be held October 31 through November 3,1980.
PZM AS ALTAR TABLE MIC
JOHN MURRAY, Audio Systems Engineering, Klopf Audio/Video Company, reports: “Used a PZM as
an altar table mic in a Catholic church. Sanctuary was rather live. Large multihorn cluster was above
and behind the altar with horns aimed directly down over the altar area. The PZM provided better
gain and highs before feedback than the existing cardioid condensor. The off-axis pickup of the
PZM was exceptional.”
PZM IN CORNER PICKS UP DISCUSSION
KERMIT ANDERSON, Sonoma State University, used a PZM in the upper corner of the room to
record a round-table discussion and a grievance hearing. A cassette recorder was used on auto-level
with excellent results. Set-up was easier and quicker than previous method with multiple mikes and
the barrel effect of too-many microphones.
A TITANIC USE FOR PZM
In the movie, “Raising the Titanic,” some of the moving scenes require close voice pickup while the
camera is being dollied. The soundman put a PZM on the front of the dolly and had his sound close,
staying with the action.
PROGRAM ON PZM AT CHICAGO ACOUSTIC AND AUDIO GROUP
KEN WAHRENBROCK presented a program covering the use of PZM in radio, television, theater,
classical reinforcement and recording. After September 10,1980, an edited version of the paper will be
available from Crown.
WOLF TRAP AND PZM
FARREL BECKER and the sound team at Wolf Trap Farm have reworked the main speaker system
this past spring. The design with its coverage is exceptional from the main seating area, through the
balconies to the open grass area outside. It was interesting to observe the clarity of the reinforcement.
When the National Symphony Orchestra is playing, there is no need for reinforcement in the house.
Two PZMs are placed over the center of the proscenium to feed the outside system on digital signal
delay. It is possible to move from the main room to the grass without noticing a shift in sound quality. A
recent performance with Yahuidi Menhuin fora violin concerto, using a PZM on a 2' square plate on a
low stand, moved the audience in the balcony and on the lawn right up front for listening. The richness
of the tone was all there.
An earlier performance by a jazz group, which decided to use all of their own microphones, was even
more noticeable for the complete lack of realistic sound provided for the speaker system. The only
instrument that sounded like it was real was the drum set. Piano, trumpet, sax, flute, Soloist and bass
all sounded like they were coming out of “run over by a truck” earphones.
Earlier in the summer at the “opening gala,” PZM was used by Liza Minelli and Rod McKuen with great
interest and appreciation.
SAN DIEGO OPERA
Recent productions of the San Diego Opera Company utilized PZM for recording with two PZM2-1/2
for the stage and two PZM-C’s in the pit for the orchestra. The balance and clarity of the recording
delighted the musical directors, conductors and opera executives.
In “Joan of Arc” several sound effects were miked with conventional mikes since they did not have
sufficient PZMs to use for off-stage choirs. The contrast was significant. Future presentations of the
Opera Company will be completely miked with PZMs.
“FORTY-SECOND STREET” AT KENNEDY CENTER
Five PZM’s are being used in the new show, “Forty-second Street,” at the Kennedy Center for several
weeks before going to Broadway in New York. Three are being used downstage for tap dance pickup.
One is on HME wireless for an upstage raised acting area and one on the piano. LENNY WILLS is
soundman with RICHIE FITZGERALD as sound designer with Sound Associates of New York City.
PZM AT ACADEMY AWARDS
The testing of PZM for the lecterns did not work out since they picked up too much on-and-off-stage
noises and preparations for the next scene, which intruded on the sound for the TV program. They
were used for audience participation for the TV broadcast.
SHOWBOAT COULD HAVE USED PZM
A recent visit to the National Theater in Washington, D.C. caught the last performance of “Showboat.”
The show is excellent but the touring company sought to save money at the wrong place in neglecting the sound coverage and microphone pickup. Much of the music and significant dialogue were
missed for lack of clarity.
In discussion with the sound engineer traveling with the troupe, his comment was, “They didn’t want
to spend the money. The show closed two weeks early for lack of attendance. With such an excellent
vehicle, it’s too bad one had difficulty in hearing. I wonder how many persons would have encouraged
others to attend if they had been able to hear the show?
RICHARD TODD at Busch Gardens, Williamsburg, VA, was setting up a traveling group and suggested PZM on the piano. The group demanded the Heppensteil that was in their contract, so he
placed both it and the PZM on the piano and had the music director of the group do an A-B. The
choice was PZM. Add another convert.
PZMs USED FOR MUSICAL
Orange Coast College in Southern California is presenting its summer musical, “Company,” with an
interesting multi-level stage. Three PZM21/2’S cover the main Stage action with great clarity. Six
PZM-D’s give close coverage for the smaller elevated stages. PZM3 is placed under the bridge to
cover the upstage floor action.
INTRODUCING THE CROWN PZM:
THE SECOND MAJOR ADVANCE IN MICROPHONES IN 100 YEARS.
In 1876, Bell invented the first microphone.
Crown now announces the second microphone - the PZM.
During the last century, microphones have been much improved, but they still employ Bell’s basic
concept: a movable diaphragm connected to a transducer, the whole assembly intended to be stuck
out in the air somewhere near the sound source. Comb filtering can be a side effect of that design.
Every Bell-design microphone demonstrates frequency response anomalies when used near a reflective surface because of an inability to satisfactorily combine direct and reflected signals. Phase-induced amplitude cancellation and reinforcement are the inevitable result.
Crown PZM microphones eliminate comb filtering from the primary boundary because they detect
sound according to a new principle, the Pressure Recording Process. As a sound wave approaches a
boundary (wall, table, floor) a pressure field four or five millimeters deep forms at the boundary, within
which the direct signal and its reflection from the boundary add coherently and remain in phase.
The Crown PZM places a small pressure transducer into the primary boundary pressure zone, eliminating the possibility of phase-induced interference. The PZM concept thus provides a significant
improvement in signal quality. Its small profile also improves microphone aesthetics. The PZM
pickkup pattern is hemispherical, with no off-axis position.
Singers and speakers can move more freely around the PZM. Gain related to distance will change,
but not tonal quality. The PZM responds accurately to SPL up to 150dB. You can put it right inside a
drum, a bass fiddle, or a piano. The PZM hears whispered conversations in an ordinary room at thirty
feet. In certain situations where undesired ambient noise can’t be eliminated, or in halls with poor
acoustics, the PZM probably should not be used-it will pick up everything. Singers, orchestra conductors, pianists, percussionists, broadcasters have all tried - and praised - the PZM.
Recording engineers find that the PZM suggests new miking techniques. For small groups it now
seems that the best place for a PZM is on the floor! Recording and reinforcement may well require
fewer PZM mikes.
Several PZM models are now available, including a clip-on and recessed model for permanent installation.
The PZM is changing ideas about how a microphone ought to sound, look and be used. Find out for
yourself how it might improve your own recording or reinforcement systems.
PZM, PZMicrophone and Pressure Zone Microphone are trademarks of Crown International.
###
PZM MEMO
March, 1981
Ken Wahrenbrock, Senior Editor
PZM SEMINAR IN ELKHART
November 17 1980, Crown sales representatives gathered at the Ramada Inn in Elkhart for a one day
training seminar on Pressure Zone Microphones, conducted by Ken Wahrenbrock and Dave Andrews.
Dave Andrews, New York sound contractor who is most recently known for his work on the New York
Hilton sound system, worked for several hours with the representatives, helping them to understand
how the PZMicrophones can best be demorstrated and used. Included were details on places where
Wahrenbrock and Andrews have found that the PZM should not be used.
Fig. 1. Dave Andrews (right).
The seminar included a tour of the Crown factory, especially those parts of the facility now devoted to
assembling and testing the PZMicrophones.
Fig. 2. Don Eger (left), Crown PZM Project Manager, and Ken Wahrenbrock check out the PZM test facility
prior to the tour by the representatives.
PZM EXTENDED BASS MODEL ADDED
Crown has added the PZM 31S [now the PZM-30D] to its line, offering a somewhat ditterent frequency
response curve to users. The new mike offers deeper bass response, as well as a warmer high end
(in contrast to the 3OGP and 6LP, which have a bright, crisp high end). Suggested applications include piano and kick drum miking, as well as close miking situations.
The 31S is now in production, and is available in a silver and black color scheme. The plate ot the 315
is 15cm x 13cm (6x5in.).
NOTE: Some of the news items in this issue may have reference to experimental models of the PZM
microphone which have not yet been completely engineered for production. We do encourage your
consideration and evaluation of these developmental models, but not all of them may result in production models available for general sale. Watch these columns for notice of new PZM models available
from Crown.
BAKER’S KEYBOARD LOUNGE GOES PZM FOR PIANO
The oldest jazz club in the USA was the scene of an interesting demo by T.S. Taylor. The pianist was
using a three mike setup which provided adequate sound. He insisted that the lid of his Steinway be
left off.
T.S. crawled under the piano, used some duct tape for mechanical isolation on one of the horizontal
support members and mounted a PZM about 2½ inches away from the sounding board. He wanted to
test the location.
The piano tuner came in, saw no microphones and proceeded to tune the piano. He was unaware that
the PZM was feeding the monitor system, but not the house system at the moment T.S. was chatting
with him and smiled at his comment that “old Betsey” was sounding especially good that day. The
humidifier and all were finally matched.
T.S. went back and clicked off the PZM. It created a “howl to awake hibernating bears.” Richard, the
tuner, yelled, “T.S. what are you doing to me?” He forgot all about the Steinway for 45 minutes while
T.S. took him step by step through PZM technology and applications. After the education, Richard’s
response was, “Turn it back on; I’ll never be able to get it tuned without it now.”
The tuner now wants a rental arrangement for another PZM.
Clarence Baker, the owner, returned and expressed amazement at the piano sound and its microphone placement.
One additional comment. The piano player for that next weekend arrived with his own PZM, purchased in New York to take with him on the road.
CANNONBALL ADDERLY JAZZ FESTIVAL
On October 1-6,I was given the distinct pleasure of being chief engineer tor the 1st Cannonball
Adderly Jazz Festival.
Southern Sound of Tallahassee set three different types of rooms ranging from small, dead rooms to a
large, live gym.
The piano was a 9' Steinway. The local Crown dealer, Stereo Sales, Willie Marasco, loaned a 3OGP
PZM [now the PZM-30D]. I taped the mike to the inside of the lid just over and slightly forward of the
crossing of the bass strings and the midrange strings. The presence of a crossbrace on the lid prevented me from moving the pickup further forward and out.
The Nat Adderly rhythmn section, Larry Willis on piano, Walter Booker on bass, Timmy Cobb on
drums, backed up most of the solo “name” artists. Because of the intimacy of the music and setup, the
piano (lid always open) was within 3’of the ride cymbal. This caused proximity problems on the high
end of the PZM. Slight attenuation on the board solved the problem but compromised the piano
sound. As sound engineer, I was probably the only one who was aware of that problem.
The sound of the piano in all the rooms was so nice and clear, responsive and lust plain real, I had to
write.
Even performers such as Larry Willis, Dr, Billy Taylor, Mary Lou Williams and especially Ramsey
Lewis were totally pleased with their sound thru the monitors (no feedback at all) through the house
system. Already a Crown power amp person, I would like to thank Ken Wahrenbrock and Crown for
this product. My job just became easier and more pleasurable.
Bruce Johnson, Tallahassee, Florida
BUCKNELL JAZZ & ROCK ENSEMBLE
PZM ON WILLIE NELSON’S PIANO
After exposure to PZM’s on the piano in Las Vegas, thanks to Chips Davis, a PZM was purchased for
Willie Nelson’s show at the Universal Ampitheater in Hollywood. Some WSA staff attended to check
out the sound and reported that it was nice to have a crisp piano rather than a jumble of sound, Pete,
Willie’s sound man, stated that they were the best mics he’s heard. The piano player is Willie’s sister,
Bobbie; she is featured quite a bit.
We found very favorable results miking the grand piano during a studio session with the 20-piece
Bucknell Jazz & Rock Ensemble. The piano was miked with 1 PZM model A taped to the lid which
was closed. With the horn section no more than 5 feet away, the isolation was superb. Also, the sound
was so natural and non-resonant that we were able to cut the piano track with no EQ. Not only did the
PZM capture the desirable frequency response and isolation we wanted, but when the piano was
panned to the center during the final mix-down, it gave the apparent feeling that the piano was very
wide and did not sound like a single source microphone was used. We and the group were very
pleased with the final results. The album on the Tunisia label is scheduled to be released October,
1980. JUDGE FOR YOURSELF.
Scott Gelnett, Susquehanna Sound, Northumberland, PA
WHAT’S NEW WITH PZM/PIANO?
In a sound reinforcement pick-up of the Cedar Rapids Symphony outdoors, I had great success with a
PZM on an upright piano. I taped it on the outside, to one of the large upright supports facing the
sounding board. By positioning in the upper corner the capsule was surrounded by sounding board,
reflecting plate and 2 supports but was not completely enclosed. This gave excellent isolation. with the
clarity we’ve come to expect from PZMicrophones. Actually the piano sounded better than it had any
right to!
Thought you’d enjoy hearing yet another war story!
Bruce A. Thayer, Division Manager, WMT Music & Sound
PZM ON UPRIGHT PIANO
An additional placement for PZM’s on an upright piano is to place one or two PZM’s on the inside of
the cover just above the pedals.
Wade Bray of Kimball International tried such an arrangement and a Baldwin sounded just like a
Steinway.
DIFFERENT BASSES: DIFFERENT PZM PLACES
There doesn’t seem to be a standard place for PZM on string basses. Can you help? There is considerable difference in the sound of basses using the PZM. The quality of the bass will determine the
sound developed for the microphone. It may also require a different mike placement depending upon
the quality of the bass. Inexpensive basses are quite different in sound and placement from the best
made German bass instruments.
PZMs HAVE TOO-DEEP BASS FOR SOME APPLICATIONS
Paul Morrow from Acoustic Design Associates, who designed some special flush mountings, found
that with one of the capsules there was more bass than the automatic mixers could handle. The air
conditioning noise would trigger the mixer.
Their solution was to replace the 2 uF input capacitor in the power supply with a .047 uF and thus rolloff the bass.
Others may find this solution helpful.
PZM GOES TO A PARADE
Robert Houser, Audio Engineer, KTLA-TV, Channel 50, S. California, used 2 PZM-GLP’s [now the
PZM-6D] on 2’x2' pieces of stiff cardboard taped to street lightpoles 15' above the ground. That was
the pickup for the Anaheim Halloween parade on Nov. 1 presented live on Channel 50. It was taped
and replayed on Nov. 2.
KTLA, Channel 5, bought the show and replayed it the following weekend.
The pickup was for the band and float sounds and provided exceptional clarity as compared to the
free field mikes usually used. At one point the mixer compared the difference on the show.
PZMs ON PIANO
Jim Hudson, who provides entertainment for the guests at the Milwaukee Hyatt-Regency’s Atrium
cocktail lounge, came to us with a request to solve the problems with the dull, weak sound his piano
player was getting. The piano is on a carpeted floor in the Atrium, which is the Hyatt trademark, This
space provided just one reflective surface for the piano; since most of the sound we hear is reflected,
the five missing surfaces were quite evident. The PZMicrophones’ unique clarity and transparency
gave the audience psychoacoustic suggestion of a much more “present” piano; measurements indi-
cated no high frequency lift, but rather a low frequency lift and the average volume of the piano remained unchanged - to the management’s delight since the piano was more audible but didn’t cause
problems with guest rooms opening onto the Atrium.
Peter Neupertz, Flanner’s Pro Audio, Milwaukee, WI
PZM IN KICK FOR FAT LOWS
Recently we’ve been experimenting with the PZM in a studio situation. For years I’ve been experimenting with drum sounds, trying to get a fat low end sound without slop. The PZM has come through
with the sound we have wanted. We simply throw a PZM in the kick drum on top of the towels and the
sound is there. All we can say is look out Neumann!
Phil Langdon, Baumann Music, Arlington Heights, IL
OVERHEAD DRUM MIKING WITH PZMs
“In the beginning there was sound. Now there is the “PZM.” These mikes are truly a representative of
the ‘80’s.
We are using two for stereo overheads on drums and close miking the double kicks with SM-57’s on a
12-piece drum set in an open aircage. The natural L to R pan in the control room puts you in the
drummer’s seat.
Acoustic 6 or 12 string guitar through a Leslie with stereo L & R 130’s is devastating. The mikes make
your imagination cringe with the countless possibilities.”
Alan R. Cahen, Infinity Recording, Tulsa, OK
PZM GOES TO THE MOVIES
I have used two PZM’s for SFX Recordings in stereo for an upcoming picture “Uforia”; also for Neil
Young’s new picture, “Human Hiway.” The best FX mike ever devised. Works well on the floor as a
dialogue mike for wide shots when the other alternative would be a boom mike from above especially
in boomy, tubby rooms. You should make some with clear Lexan plates; they would be less conspicuous.
Kirk Francis Beverly Hills, CA
PZM GOES TO THE THEATER
The sound engineer for a theater came in and rented 6 PZM-3OGP’s [now the PZM-30D] and 10 AKG
451’s for the show. After one rehearsal he brought back the 10 451’s. When queried about the reason
for returning the mikes and checking to see if they were defective, the answer was, “I don’t need
them, the PZM’s cover the show perfectly.”
Phil Clark, Diversified Concepts, Marcellus, NY
PZM GOES TO CHURCH
John Murray of KLOPF Audio-Video Co. placed a PZM on the altar of a Catholic church which was
very live. A large multi-horn speaker cluster was above and behind the altar with horns aimed directly
down over the altar area.
The PZM provided better highs and gain before feedback than the existing cardiod condenser on a
stand. Off-axis pickup with the PZM was exceptional.
PZM GOES TO CHURCH - AGAIN
Carl Derr in Emoryville, CA, installed a church sound system and in providing microphones suggested
a PZM lavalier. The minister emphatically rejected any lavalier as noisy, poor sound and worthless.
Carl suggested just one service and left it for the next Sunday. On Monday the response was: “This is
my microphone, you cannot have it back!
PZM ON SYRACUSE ORCHESTRA AND CHORUS
I must report on our fantastic success in using PZM’s for reinforcing the sound ofthe Syracuse Symphony Orchestra and Chorus during their Fay’s Christmas Concert at the Onondaga County War
Memorial Auditorium in Syracuse, New York, on December 7,1980.
The orchestra was located in the center of the 2 million cubic foot auditorium where they were surrounded by more than 7,000 listeners. Since an orchestra shell could not be used with this configuration, the temporary loudspeaker cluster, which was hung about 40 feet over the center of the orchestra, was required to cover the full circle of listeners plus act as stage monitor for the orchestra.
Six 3OGP type PZM’s [now the PZM-30D] were used to pick up various sections of the orchestra and
a 6LP type, attached to an 18x24 plexiglass plate, was mounted about 15 feet over the conductor’s
podium to pick up the general ambience of the orchestra. The mix was 1/3 octave equalized and fed
to the cluster of 13 Mantaray horns covering the listening area.
The results were astounding. The conductor was pleased because he could hear the entire orchestra
even better than with the orchestra shell. The stage manager asked if it was turned on because he
couldn’t “hear” the sound system, although he could hear the orchestra very well. The critics were
apparently pleased because all they wrote about was the “clear rendition” of the various portions of
the program. And many listeners took the time to compliment us on the quality of the sound. Needless
to say, we were pleased with the results. But, of course, that’s why we used the PZM’s.
STUDIO USE
The last PZMemo reported on Leroy Shyne’s building of the 4’x4' plates and the great stands he
mounts them on. Since then he has used the plates for dual vocal overdubs in a studio and on a
different recording for vocals and conga drums.
He has also used the simple 3OGP’s [now the PZM-30D] for piano reinforcement for concerts with the
mikes mounted on the inside of the piano with the lid removed with excellent results.
Leroy Shyne, Shyne Sound, San Rafael, CA
I have been using 2 of the PZM’s in our studio (PZM 3OGPG) [now the PZM-30D] with incredible
results. So far the PZM’s were used on drums, piano, acoustic guitar and, vocals.
We are currently working on an album called “Homespun” featuring all local talent and the PZM mikes.
Charles Solak, Recording Studio, ASC Music Publishing, Binghamton, NY
PZMs USED AT AES NEW YORK
The prototype lavalier PZMs were used at most of the technical sessions for fhe New York Convention
of the Audio Engineering Society. When more then one microphone type was used, the greater clarity
and gain of the PZM was quite evident.
The paper’s chairman, Glen Ballou, in expressing thanks, said “I will be returning the microphone to
you shortly. Darn it.”
PZMs ON THE EAST COAST
Recent word comes that NBC New York is also using about 18 PZMs. I do location recording as well
as engineering and production at numerous studios around Boston. I haven’t used the mikes very
much yet but am excited about experimenting with them.
I am really excited about this concept, especially because it represents to me a really fundamental
shift or transformation beginning to take place in some engineers’ approach to technology. The willingness to experiment, to try seemingly outrageous ideas and techniques to get results rather than staying enmeshed in preconceived ideas about “the right way to do it” really opens up an entire new
panorama of possibilities for our ears and minds to explore.
David Litman, Other End Production, Carlisle, MA
EXPERIMENTAL MODELS
NOTE: Some of the news items in this issue may have reference to experimental models of the PZM
microphone which have not yet been completely engineered for production, We do encourage your
consideration and evaluation of these developmental models, but not all of them may result in production models available for general sale. Watch these columns for notice of new PZM models available
from Crown.
###
PZM MEMO
November 1981
Ken Wahrenbrock, Senior Editor
PZMICROPHONE HONORED
We have often remarked on the durability of the PZMicrophone design and its ability to stand up to
rough usage without damage.
Much of that ruggedness is due to a new reinforced plastic called “FIBERFIL” which Crown’s design
engineers selected for the capsule housing.
The manufacturer of FIBERFIL, Division of Dart Industries, recently invited a number of people to
Chicago for the presentation of a series of awards to companies whose products illustrated creative
uses of their plastic. One of the products singled out for this honor was PZMicrophone.
Don Eger and Verne Searer, members of Crown’s engineering staff, attended the meeting and accepted the award on behalf of all the smart people at Crown.
PZM AND GUITAR
A couple of ideas on guitar pickup come to us from Chips Davis of Las Vegas Recording. A handheld
prototype he has been evaluating for us proved to work quite well on a flex holder 12" from the front of
the quitar. He has also used a PZM-30GP [now the PZM-30D] on a short stand. K.W. thinks that an
even better idea would be a 6LP [now the PZM-6D] on a piece of plexiglass 18" square, mounted on a
low stand and tilted to provide good separation from the monitors.
PZM ARTICLES
db, the sound engineering magazine, used a beautiful color photo of PZM on its front cover for the
June issue. Inside the magazine was a major article on the theory and practice of PZM, authored by
our own Clay Barclay.
Recording Engineer/Producer for June includes a lengthy article on the sound system developed by
A-1 Audio for Barry Manilow’s tours for 1980 and 81. The article includes significant mentions of how
Manilow used PZMikes, especially for his piano.
PZMs IN THE STUDIO
Robert Margouleff, an independent recording engineer, has used PZMikes for congas. One overhead
and one below. Ed Bannon of Las Vegas Recording has found a PZM/piano system that works very
well for rock music. One PZM is mounted on the underside of the lid, centered. The lid is placed on
the short stick and a second PZM is fastened to the stick facing the high end strings.
Chips Davis (also Las Vegas Recording) puts a PZM-30GP [now the PZM-30D] on a boom stand over
and in front of trumpets for excellent pickup on multichannel miking.
Chips has also installed two 30GP’s in a V-shape above the drum set. He also finds it helps to use a
PZM mounted on the wall in front of the kick.
PZM DROWNS; WE’RE ALL AT SEA
Charles Bilello of West Hempstead, NY, writes concerning the use of a hand-held PZM with a small
windscreen for vocals. After three hours, the mike began frying, was muffled and went dead. Gap
between capsule and boundary was filled with moisture. After drying out, it worked perfectly. Have
tried a U87 windscreen, but it cuts oft highs too much on PZM. Charles needs help. Does anyone
know of a windscreen that is moisture proof that won’t muffle the sound? Write us and we’ll forward
the information to Charles. Chips Davis, of Las Vegas Recording, has been tying a prototype PZM
handheld with a double windscreen for recording vocals and reports that it works quite well. He hasn’t
mentioned - so far -any problems with moisture.
NEW HOPE FOR FLYING PZMs
We have come across a nifty new product that might be helpful to those of you who are flying
PZMicrophones on overhead panels. It’s called Pyramount, and it’s a fixture that mounts to the ceiling
(it could be attached to a boom, too). It makes it easy to position your PZM panel at any angle you
want.
PROTECTING THE PZM NAME
We obviously think that the PZMicrophone is a valuable contribution to the art of microphony. Valuable
enough that we would like everyone to recognize the fact that the original PzMicrophone is manufactured by Crown, and only by Crown. Crown, in fact, is the only manufacturer authorized by the inventor of the Pressure Recording Process to use the words PZM, PZMicrophone, or Pressure Zone
Microphone to describe the product.
But we have to work hard to maintain that kind of identity. It is important for us to do that, since it is
inevitable that someone, someday will be manufacturing microphones which may look and act like
PZMicrophones. Unless we have licensed them to do so they cannot be referred to as the PZM.
So, would you help us by reminding your friends in the publishing business, who may have occasion
to write about PZMicrophones; to find some way to acknowledge the fact that these names are trademarks, that they belong to Crown and can only be used if they are so identified. It’s not necessary to
identify PZM as a Crown trademark everytime if a short footnote or parenthetical statement is utilized,
i.e., “PZM is a trademark for microphones manufactured by Crown International, Elkhart, IN.” Thanks.
We appreciate your help.
K.W.
Pressure Recording Process (PRP) is a trademark owned by E M. Long Associates and used by
permission.
PZM ON STAGE
Our auditorium has an incredible problem with acoustics. I was amazed with the performance of the
PZMicrophones I used for a musical (PZM 2-1/2) [now replaced by the PCC-160]. They responded
with the best sound reinforcement I have heard in our auditorium and I have experimented with a
great number of microphones in the last five years. PZM’s are the best thing to come along in stage
theatrical sound reinforcment.
David H. Dunbrack, Auditorium Manager, Huntington Beach High School, CA
MORE ON PZM PYRAMID
Carl Haye of Micar Audio, Independence, MO, has made a 4 sided pyramid using a 30GP [now the
PZM-30D] but is going to change it to a 6LP [now the PZM-6D] bar and capsule. He measured with a
real time analyzer and estimated more than 12dB gain over the PZM placed on the stage floor. He laid
the pyramid at the stage front and had good gain to 20' upstage.
If you need to use us as a referral for the Crown microphones, please feel free to do so. They have
been an added asset.
Sincerely,
Michael L. Medley, Northland Cathedral Assembly of God, Kansas City, MO
MORE HELP WANTED
I want to know how far apart two, or three 30GP [now the PZM-30D] PZMikes can be placed and still
maintain phasing foran organ recording that will be made into a record. I want the mikes to be flat on
the floor, on 4’x4' plywood over a carpet. I have read Application Note #12 suggesting a wedge with
the mics 7" apart.
What new “liberties” are there for phasing with the PZM process that conventional mikes do not allow?
James E. Brackett, Shangri-La Cottage, Epworth Heights, Ludington, Ml 49431
A Response From Ken Wahrenbrock:
PZM technology has not changed the problem of spaced microphones when recording for disc. In
such a situation, where the engineer needs to sum and difference the two microphones, the L-R mix
(which is the vertical excursion of cutter or stylus) will create intense cancellations and a 3 dB addition
for high amplitude signals which may arrive at the mikes at different times. It was to solve this problem
that the “coincident crossed pair” configuration was developed. Placing PzMicrophones on either side
of a plate or wedge is the PZM equivalent of the “CCP.”
As to the second question, there are no particular phasing liberties available only with PZMikes. If you
are doing multiple miking with spaced PZMikes for sound reinforcement you do not get as much
“dropin/dropout” process, but it does not reduce the recording-for-disc problems.
I have recorded organ with spaced PZMikes, when the final materials were tape or cassettes, with
exceptionally good results; but were I to be recording for disc, I would use a PZM on either side of a
plate or wedge to get a stereo image without phase cancellation problems.
PZM & PlANO - UPRIGHT VARIETY
We have heard about another possibility for placement of the PZMicrophone with an upright piano.
Put the mike on a wall in back of the piano and adjust the distance from wall to sounding board for
best sound. The piano can also be moved sideways for best bass/treble balance. Our thanks to Don
Eger of Crown’s marketing staff for this one, as an answer to an inquiry from C. W. Lytle of Fairbury,
Nebraska, who wrote us with a concern about excessive buildup of bass notes.
PZM GOES TO THE OPERA
A letter to Murray Young from Chris Wood, sound engineer from the San Francisco Opera, dated 4/
20/81:
..... We have three Wahrenbrock PZM’s that we are very happy with. Two live during the season on
the upstage wall of the orchestra pit. The orchestra sound from these is put into a 70V system for
onstage (behind the set) choruses and bands (musicians). The third lives on the balcony rail where it
picks up orchestra with singers for our video archive system. We are hoping to expand our PZM use
into the more traditional reinforcement-type areas. The lack of coloration in the PZM is a prime factor
when mixing real and amplified sound.”
A LETTER FROM SUPERIOR SOUND, KANSAS CITY, MO:
The Crown microphones we purchased have been superb. The added pickup... is really unbelievable.
Also.. have given us a much better mix of the choir voices.
CONCERT RECORDING WITH PZMs
TO: Bert Spangler, Audio Coordinator, Media Development Center, University of Wisconsin - Eau
Claire
FROM:Larry Glenn
DATE: December 22, 1980
SUBJECT: Evaluation of Crown PZM Microphones
I have used the Crown PZM microphones along with microphones which we have normally used for
recording several concerts and recitals this fall. I have found them to be quite useful in some situations and would recommend their purchase.
As I normally do only recording of music, I have not had opportunities to evaluate their performance
for speech. I did make one test for this purpose. I mounted the PZM on the ceiling in a classroom and
made a recording while I walked around the classroom and talked. I repeated the test with a dynamic
cardiod microphone mounted in the same location. I found the sound of the PZM was clearer and less
clouded by room reverberation.
For music recording I have used the PZM’s one at a time as highlight microphones, as a pair for basic
stereo image pick-up, and at stage edge for vocal pick-up during an opera performance. I found them
suitable for some instruments as a close highlight microphone, but not for all instruments. They
worked well with piano and with wind ensembles. I placed one directly under the piano in the first
case, and 10 to 15 feet away in the second case.
I also used one on the floor about 6 feet in front of a performer playing the oboe. The sound was
definitely clear, but the performer had too “raw” a sound, compared to an overhead microphone.
(Editor’s Note: The performer principally hears the oboe from reflected sound. The PZM was exposed
to direct or “raw” sound, which would sound unusual to the performer. - K. W.) As a basic stereo pair
for choral pickup at 15 to 20 feet away, I found them too bright, accentuating the sibilance problem we
have in the concert hall. When I mounted them on ceiling beams in the arena at 30 to 50 feet from the
performers, they performed very well, giving a good balance between a large chorus and orchestra.
For each of the above applications I was able to compare the PZM’s to other microphones. I also used
them at the edge of the concert hall stage for vocal pick-up during an opera. I did not use other microphones on the floor to compare them to. I used them to mix in with the main stereo pick-up I was
using to increase the clarity of voices as the performers moved around the stage. They were somewhat bright but were acceptable for this use. Their low profile made them a good choice for floor
placement and I did not find objectionable noise from footsteps.
If purchased, I am sure we will find them a useful addition to our present selection of microphones.
NY JAZZ FESTIVAL
The Los Angeles Times (and other papers for all we know) carried a story on July 8, 1981, reviewing
what used to be called the Newport Jazz Festival. The article as we saw it included a large photo of
Diny Gillespie blowing his horn, in front of a highly visible PZMicrophone, at Carnegie Hall.
Unfortunately, the reviewer was too involved with the music to pay any attention to the mike; so we
don’t know what he thought of it.
K.W.
PZMs FOR CLASSROOM, VOICEOVERS, INTERVIEWS
DATE; January 23,1981
TO: Burton Spangler, Audio Coordinator, University of Wisconsin-Eau Claire
FROM: Lawrence Cheng, Audio Recording Specialist
SUBJECT: Crown PZM Microphones
The Crown PZM -30GPB (now the PZM-30D) microphone was used in three experimental situations.
Its performance characteristics were found to be quite different from that of a “typical” dynamic microphone.
(1) In a classroom
The PZM was mounted on a rigid board (2’x4') on the ceiling above the first row. A dynamic microphone with an omni pattern was mounted a few inches beside the PZM. A moving sound source was
picked up by these two mics and recorded onto separate tracks. The tape was analyzed later. It was
found that the PZM channel had a better sound. The highs were “crisper”; speech appeared more
intelligible. A more important aspect was that the PZM channel sounded “closer’ regardless of the
position of the sound source in the room. Interestingly, EQ alone was unable to bring the perspective
of the dynamic channel as “close” as that of the PZM channel.
(2) In a recording booth
The table top was padded. It was discovered that placing the PZM on a sheet of metal (2’x4') improved the quality of sound noticeably. Despite the fact that the PZM sounded a bit “nasal,” it performed satisfactorily. However, in an AB test, the Neumann U87i was preferred.
(3) In Department of Allied Health Interview Rooms
Findings were similar to those found in the classroom. Room sound was more evident in the PZM
channel.
In general, if both the capacity as well as the limitations of the PZM were clearly understood, it can be
a valuable tool for any recording engineer.
PZM ON THE AIR
Mark Heller, Chief Engineer for WVON/WGCI in Chicago, writes:
WGCI in Chicago uses its PZM to record all public affairs programs.
In our studio, we found that by adding a rumble filter after the mic and then using an equalizer we
increased the lost bass due to the studio picking up the air conditioner overhead.
WVON uses it for the nightly talk show from 10 PM - 12 midnight - Hotline. The new mic allows better
freedom and less formality than the Sony electret lavaliers we had been using.
We are very happy and have suggested that our TV station inDenver consider it for their newscast
operation at “NINE ALIVES ACTION NEWSCENTER.”
Thank you, Mark.
PZM & ENG
“ENG” as most of you already know stands for electronic news-gathering. Remote trucks equipped
with mini-cameras scurry all over the landscape to tape the latest news or even transmit a live remote
back to the studio so the news staff can bring the viewers the news as it happens.
It seems to us that this might be a great place for a microphone with the capabilities of the PZM, but
we haven’t yet heard about anyone who has tried it out for that. Anyone care to let us know of their
experience with PZM & ENG?
K.W.
PZMs: OPERA IN ISRAEL
Now I would like to relate to you two instances in which we have used the PZM with unprecedented,
fantastic success in Israeli terms, and I believe in any terms.
A classical music festival was held in one of Israel’s leading concert halls. There was a need to amplify music played inside the hall to a park outside where 2000 people, who could not get tickets, were
assembled.
We put up two Bose 802 speakers on high stands outside the hall and the PZM 31S [now the PZM30D] at the front of the stage inside the hall, where the actual concert was taking place.
The program consisted of small classical groups, choirs singing songs from the Renaissance and an
opera.
The audience in the park outside was surprised by the high quality of the sound; and the director of
the festival, Mr. Noam Sherif, asked us if it was a master tape he was hearing.
He could not believe that what he was hearing was really coming from inside the hall and at such high
quality. His surprise grew when he went inside and could not detect any microphones.
The reviews were outstanding; and when we compared the microphones with others, there was a
great difference in the volume and clarity of the sound.
Another most complicated project was amplifying the sound of the opera “II Troubadour” played by the
Genova Opera of Italy, in Jerusalum.
This is an open air venue with a great view of Jerusalem. The place can hold at least 10,000 people,
so you can imagine its size.
The managers of the opera who were not accustomed to appearing with microphones were quite
worried. The company consists of a symphonic orchestra, a choir and soloists, all together numbering
220 people.
The stage was covered by an acoustic shell; the speakers were hung in a center cluster and consisted of a 5-way system, made up entirely of JBL speakers. The cluster was flown 17 meters above
the audience, and tilted a bit forward towards the audience, so as to prevent returning echoes from
the boulders that surrounded the area.
At first we had problems of feedback, and the sound engineers had to alter the sound system by
changing the low bass and the “mid” speakers into full range. We also taped some foam rubber onto
the back of the mikes used for the orchestra and for the mike at the stage front.
We placed one PZM-31S [now the PZM-30D] at the front of the stage on the floor; and we flew two
PZM-31S’s about 4 meters in the air on both sides of the stage, on a plate of 4’x4' plexiglass as you
had suggested. We had to fly the mikes a bit higher because the movements of the props during the
show kept us from lowering them.
Above the choir, which was in the back part of the stage, we flew another PZM on a 4’x4' plexiglass
plate and placed another one (for the orchestra) on the conductor’s podium.
We had to add two condenser mikes for the bass and timpani because of the difficult conditions in
which we had to work. In short, there was a lot of anxiety; the fact that our experience with the PZM
was quite brief was not comforting. To tell the truth, even we could not believe that these virtually
invisible mikes would be sufficient in that situation. All the professional material you sent us could not
convince us either.
The minute the dress rehearsal began, our fears subsided. The people from the opera could not
believe their ears. They could not decide whether they were hearing the singer or amplified voice.
Even 100 meters from the stage, everything sounded crystal clear.
One of the interesting things is that there was a strong wind blowing during the show and all the
overhanging mikes were swaying widely. Yet the wind could not be heard at all through the PZMikes
while the two condensers were noisy, even though they were shielded by windscreens.
The critics could not and would not believe that there was any amplification. They could not understand how every detail was heard, and yet there were no visible mikes.
I think this is a great compliment for the mikes. As a result of this success we became the first professional equipment hiring company in Israel to be invited abroad to prepare the sound design for the
International Ballet Festival in Alervi, Italy, a festival which is now taking place.
We hope to send the reviews as soon as our crews return from Italy.
Asher Bitansky, Mor Productions, Tel Aviv, Israel
THE AMBIENT NOISE PROBLEM
Pro Sound News, in a recent issue, provided some sound advice to studio owners contemplating
conversion for video production. The author, Peter S. Neupert comments about the PZM:
“The acoustic environment in television studios is terrible. They are too live and too noisy. We have
been taking Crown PZMicrophones around to television and video production houses where its unique
properties make it a fantastic problem solver when you encounter amateur talent, mike-shy people,
reach problems, sightlines problems, etc. But if the studio is too noisy, it will not work at all.”
The sense of what Peter is saying is not that the PZMike won’t work, but that it works too well. As we
have mentioned on many occasions, the reach of the PZM configuration does make it unsuitable for
use in a noisy environment. Other manufacturers, please take note - PZM can’t do everything!
EXPERIMENTING WITH PZM
Thank you for sending me a pair of Crown PZM’s for test and evaluation . . . I really enjoyed working
with the PZM’s.
I got the opportunity to use the PZM’s along with some other mikes (Sony’s ECM-50PS, AKG’s C-451
+CK-1, and Aitec’s 654) to record a small bluegrass/rock group.
Since we were recording in a rather large room, I tried an experiment in multi-mike technique that
worked quite nicely. I used the ECM-50’s for acoustic guitar pickups, the 654’s for vocal pick-up, and
the PZM’s mounted back-to-back on a 4-foot-square sheet of plexiglas for stereo room pick-up. The
perfect stereo omni! The PZM’s served as the main source, with the other four mics mixed-in as
needed for presence and localization. The reverb we were able to pick up from the room in this manner was much better than what we were used to hearing from other mics used from room pick-up, and
an order of magnitude better than using spring reverbs to enhance the sound.
I am looking forward to using some PZM’s on my next job.
Sincerely yours,
Mike Sullivan, Hoover-Keith Associates, Inc., Houston, Texas
PZM INFO FROM SYN-AUD-CON
The Winter ’81 edition of Don Davis’ SYN-AUD-CON newsletter contained the following comment:
“Glen Ballou reports making a helicopter noise tape (he works for Sikorsky Aircraft) of a takeoff, fly-by
and landing using a Crown PZM. He states that the recording was done in 20 degree weather with 20
knot winds. Even when the helicopter flew directly overhead at 50' altitude, the wind noise was minimal. He concludes ‘Another good use of PZM’s.’ Have you tried Crown’s PZM’s with their phenomenal
freedom from vibration pickup, wind noise and shock? You’ll be pleasantly surprised when you do.”
PZM HIGH IN THE ROCKIES
Rocky Mountain High Note, published in the Denver area by Front Range Publishing, included an
article in a recent issue by Marc Farley, editor, on a PZM seminar given by Barath Acoustics of Denver. Farley reports that he was duly impressed with the “funny looking gizmo,” and detailed a lengthy
interview with Ken Wahrenbrock, who represented Crown at the seminar.
###
PZM MEMO
February 1982
Ken Wahrenbrock, Senior Editor
PZM SCORES IN RADIO
We purchased the PZMicrophones after a most impressive demonstration of some prototypes by
Barny Cole of Calf Audio in Ithaca. As we record the Binghamton Symphony... we felt the PZMwould
be beneficial... we have used the PZMicrophone in primarily a coincident stereo pair and spaced omni
configuration. We rely primarily on AKG 421’s and CGI’s for highlighting. We also sometimes use the
SM81. We do a large number of concert recordings of various size groups performing different music.
Oflen there is no rehearsal and no blocking is available. The PZMs are very useful in these situations.
Their flexibility is astounding and they are also remarkably forgiving.
PZM LAVALIER DEBUTS IN NEWS BROADCAST
We have already tried out the first two PZM redundant lavalier mikes [discontinued] at a major broadcast studio in Los Angeles.
The mike was pressed into use when the first-string anchor man had to do a news spot from L.A for
national broadcast. Within 48 hours, the New York headquarters was after us to supply more of the
mikes.
Hang in there. everybody, they’re coming soon is the word from Crown.
KW
Tom Hill, FM Production Coordinator, WSKC/FM,4V, Endwell. NY
MORE ON PIANO SOUNDS
Rudy Bauskes suggests mounting a PZM mike on the underside of the lid of a grand piano, surrounded by a donut of SONEX acoustic insulating material, with an 8" hole and outside diameter as
desired. The donut damps out reverberant sound when the lid is closed and sharpens the attack for
more accurate reproduction of percussive action.
PZM SOLVES A TOUGH, SMALL PROBLEM
We were recentiy faced with a different type of application that we solved with PZM.
A local music club, open 24 hours a day, occupies three floors, It offers programmed music via jukebox four days a week and live music for some of the other three days (mostly rock, country, R&B). We
were asked to install a relay system which would mute the jukebox and bring up the live program
without turning off the jukebox (allowing the program to play out while the band was performing). The
problem was further complicated by the fact that the club does not have a house mixer.
A direct line from the band mixer band area was so small that most mixes were vocal only, and in
remote areas of the club you could not hear the instruments.
Our solution was to mount a PZM over the stage, with the power supply shorted into the relay. When
the jukebox is muted by switch, the mixer feed comes up, the PZM kicks in, and the band - vocals and
instruments - are heard throughout the club.
Chris Brown, Sound City., New Orleans, LA
FAT ELECTRIC-GUITAR SOUND
Fig. 1. PZM miking technique.
To fatten an electric guitar sound on a demo recording, we placed a PZM on the floor 3 feet away from
and facing the speaker cabinet. Since the PZM is sensitive enough to pick up the initial sound from
the speaker and the reflected sound of the mirror, a thickened sound is recorded, By experimenting
with the distance between the speaker, PZM and hard reflective surface, an ambient sound can be
obtained without adding a second mike as is the practice with other types of mikes.
Vince Motel
Downey, CA
PZM HIDES IN CHURCH
Tom Hayes, a faculty member at the University of Illinois, has built a PZM mike into an altar cross for
the ultimate in concealment.
NAGRA DEALER LOVES PZM
A NAGRA dealer friend of ours in Southern California has asked for the loan of a PZM. claiming it is
the only mike he can find that really allows him to demonstrate the fine sonic quality of the NAGRA
recorder.
— Ken Wahrenbrock
PZM & UNDERSTANDING JONESTOWN
We recently did a 90 minute radio documentary on Jim Jones and the Jonestown, Guyana, community
tragedy. Using actual recordings made by the People’s Temple of Jim Jones and his followers The FBI
had confiscated these tapes and released them after a Freedom of Information Act reques. They were
all very dry, P.A.-feed tapes recorded on inexpensive cassette machines, usually mono and A.G.C.
operated.
To provide a “feel” of what it really sounded like in the pavilion at Jonestown, we ran the tapes (after
much processing to improve fidelity and intelligibility) through a studio monitor speaker and used 2
PZM’s on either side ot the studio to pick up the room sound in stereo, which was then mixed back in
with the dry audio coming off the original tape. This greatly enhanced the quality and realism of the
program, without further compromising the already poor quality material with the conventional mike’s
“off-mike” sound. The show is entitled “Father Cares: The Last of Jonestown” and has since won
several national awards.
Skip Pizzi, National Public Radio, Washington D.C.
EXPERIMENTAL MODELS
NOTE: Some of the news items in this issue may have reference to experimental models of the PZM
microphone which have not yet been completely engineered for production. We do encourage your
consideration and evaluation of these developmental models, but not all of them may result in production models available for general sale. Watch these columns for notice of new PZM models available
from Crown.
A COUPLE OF PZM PROBLEMS WITH VOCALS
While I am very pleased with the PZM on all acoustic instruments, recording the voice is still a problem. Your new model with boosted low end is really needed here. The main problem is a hollow or
doubled sound on close miked vocals. The problem may arise from early reflections from ceiling, walls
and performer in a small vocal booth. I have used the following setup to minimize the problem:
Fig. 2. Using wall absorption when recording PZM vocals.
I would also like to know if other PZM users have had any experience with (orcan offer solutions for)
the following problems:
a. Breath and arm movement sound on acoustic guitar.
b. Low output level. On miking an acoustic guitar, my preamp gain and fade are full open.
c. Pedal and damper noises on acoustic piano with PZM on lid.
Peter D’Antonio
KW replies to Peter:
a. No solution with PZM. It will pick up all the sounds a guitarist makes.
b. Try using a PZM mounted in a large boundary (3x3' or 4x4' panel).
c. See PZM Application Note on Piano (No.5), where we suggest PZM mounted on a panel parallel to
the open lid (long stick), six to eight feet from the piano.
ANOTHER STAGE SUCCESS FOR PZM
We in Leisure Village have had many problems with sound. Whenever we put on a play, variety show
or speeches, it was necessary to hang mikes all over the stage. And even then the sound was uneven, sometimes even fading out. We have good speakers and they are judiciously placed. If an actor
spoke with his back to the audience, it was a disaster. Choral groups, worse.
That all came to an end when we purchased two PZMs. After a little experimenting we found the
answer to all our sound problems, We found that by placing one on each side of the center stage on
2’x4' plywood hung just behind and level with the teaser we could pick up great sound even when an
actor spoke with his back to the audience. Even with the curtain closed and the mikes behind the
curtain, we had good sound.
I can’t recommend them too highly.
Arthur D. Kaufmann, Technical Director
Drama Workshop and Variety Shows
Leisure Village
Camarillo, CA
PZMs IN THE STUDIO
A recent letter from Ralph Hodges, an audio editor of our acquaintance, contained the following paragraph:
“Two recording engineer friends wanted to try the PZM’s in a multi-mike studio session; and as might
be expected, they worked out less favorably under those conditions. In particular, they found that the
PZM’s directional characteristics were not helpful in suppressing “coloration” from the recording environment. In other words, they got the instrument plus room. instead of just the instrument. Stands to
reason. To sum up, I’d say that the PZMs are good to ideal for my sort of recording but not an appropriate choice for general-purpose studio work.”
KW replies:
Au contraire, Ralph, PZM has been found by many recording engineers to be an ideal choice for
multimike recording in the studio. In addition, a number of studios have two or three PZM microphones permanently mounted for overall stereo miking and for back-up tracks.
In multi-channel recording, PZMe can frequently take a whole section with less leakage than individual
instrument mikes. One of the reasons we publish PZMemo is to help users understand that conventional miking techniques may not work well with PZMs, and that its principles of operation can simplify
miking in many cases. We continue to suggest that new users of PZMs should try the PZM by itself
until the user feels that he or she understands the microphone both as to its virtues and its faults (it is
not, we agree, the solution for every recording or reinforcement situation), and then begin to use it in
combination with other microphones.
The testimony to date of the many recording engineers who have used the mike in this manner is that
it does solve many different problems for studio recordings, many of which have been described in
these pages and in PZM Application Notes.
STARLIGHT THEATER AN OLDTIMER WITH PZM PLAYS
The Starlight Theater, Balboa Park, San Diego, concentrates on the old family musical for its summer
season presentations of outdoor theater. It is also one of the earliest users of PZM microphones,
having installed them in its sound system for the 1979 season.
Bill Lewis, sound engineer for the theater, remembers the early Wahrenbrock 6x9 flat plates with
which they opened in July of 1979, and how much easier it was to mix the sound, since the earlier
condenser mikes had to be EO’d differently as the actors moved up and down stage. “The PZM not
only had better clarity,” Lewis recalls, “but it also eliminated the need to EQ differently to compensate
for actor movement. It also enormously improved the range of pickup, allowing me to follow the action
by only varying the gain.
Late in the 1980 season, Starlight tried out the PZM 2’s [now the PCC-160] made by Ken W. and now
rely on it as their standard mike.
During a performance of SHOWBOAT in the 1981 season, Lewis had to figure out a way to mike Joe,
the lead, as he started “Old Man River” on a three-foot platform all the way backstage. 25' from the
mikes. moving down and across the stage as the song proceeded. Lewis solved the problem by using
a PZM pyramid, engineered by Ken. positioned at the front of the stage. It picked up everything beautifully. Several listeners commented that it sounded as if he was using a hand-held.
“About the only problem I have ever had with the PZM mikes. of whatever variety,” Lewis said, “was
the ambient noises at the extreme reaches. I have had no probtem picking up actors at 35 to 40 feet
but you have so much gain by then, that the ambient noise can be a problem. Everybody walks on
little cat feet when we’re trying to do that.”
PZM MAKES STAGE INTRODUCTION IN CANADA
The National Film Board of Canada publishes “PERFORATIONS,” an equipment review for the performing arts. In the 1981 May-June issue, Michael Drolet, a member of NFB’s Engineering Division,
writes a lengthy article about the first use of PZMs for sound reinforcement in stage productions, The
event was the production of “Guys and Dolls” by an amateur group in Montreal.
Drolet and his associates found that the full-stage action required 2½’s (Drolet built his own reflectors)
across the front of the stage and suspended a pyramid (which they also built) twenty-five feet up at
the back of the stage.
Drolet says: “We are very pleased with the performance of the Pressure Zone Microphones which
really picked up the high frequencies even at quite a distance. This is what made the words so intelligible,. At the same time, they seemed almost immune from foot noise in the dance numbers . . . The
show was a great success!”
Thanks for your information, Michael. We’re sure next year’s production will be even better.
KW
SHAKESPEARE FESTIVAL
National Public Radio station KSOR each year broadcasts the Shakespeare Festival held in Ashland,
Oregon. The 1981 broadcast employed PZM mikes for the first time. John Patton, technical director.
and John Baxter. program director for KSOR, had sampled PZM and borrowed some mikes from KW
to do this broadcast.
The production takes place on a three-level stage, with balconies in the rear third of the stage. Action
happens on all levels, with the audience close to the stage and no amplification. The unit director
asked for 30GP’s [now PZM-30D] at center front stage, which provided audience reaction.
Both Patton and Baxter praised the tremendous dynamic range of the mike, which allowed the actors
and actresses to be picked up regardless of their distance from the mikes. No microphonics were
experienced from all of the stomping around which characterizes so much of Shakespearean drama.
The PZMs were rated much better for this purpose than conventional mikes. which had created problems in the past for KSOR because of their high visibility and difficulty in shock mounting.
A final word of praise came from other NPR stations which picked up the plays for broadcast to their
own audiences. expressing enthusiasm for the sound quality of the performances.
KW
PYRAMID TO THE RESCUE
If possible, I would appreciate plans for the “pyramid” that has been pictured in some of the memos.
I’m presently using two 2’x2' plates with a 6LP [now PZM-6D] on each. These are flown 8' high and
spaced about 15' apart and are about 4' in front of a church choir section. The sound is clear but I had
hoped for a higher level through the single speaker cluster at the apex of the “A” frame ceiling.
Part of the problem is that the speaker cluster is almost directly above the PZM plates but there is a
separation of about 20 ft, With the plates tilted into the choir I thought that the front to back rejection
would be ample enough to be able to reinforce the choir sound. Recordings sound good, but I need a
better center fill, especially to pick up the men, This is the reason that I asked about the pyramid.
Please advise any solutions.
Thank you.
Daniel L. Minnich San Bernardino, CA
PZM TEST DATA
From John Bachman, Crown PZM Product Engineer
1. I have compiled some test data in regard to your questions of 2LV behavior after being exposed to
cold and moisture.
2. Frequency response curve of PZM after 2 hours at 10 degrees F. shows no significant change from
standard response curve.
3. Frequency response of same mike after being allowed to warm to room temperature shows no
significant change from standard response curve.
4. Frequency response curve of same mike after being immersed in water for 60 seconds shows
significant distortion and a large drop in output level. We conclude that PZM is not an underwater
mike without external protection.
5. Frequency response curve of same mike after being dried by a high heat dryer for 5 minutes shows
no significant change from the standard response curve. We conclude that the PZM is not permanently damaged by water immersion.
I am confident this answers our question of temperature and moisture stability of the 2LV. Our reports
of both extremes that we have received from users have always been positive in this respect.
TELECONFERENCING AUDIO REMAINS IN ITS INFANCY
(PRO SOUND NEWS, Nov. 1, 1981)
The article, authored by Alan Gable, reviews the state of the art in teleconferencing facilities in hotels
and corporations in the U.S., with special attention devoted to the generally low quality of sound
transmission provided by most of the hotel systems. Corporations seem to be more concerned with
sound quality and claim to be installing systems which satisfy the most critical listeners.
One paragraph is worth reprinting in its entirety:
“One item that has been proven effective enough for widespread acceptance is the Crown line of
patented Pressure Zone Microphones (PZM). Marv Welkowitz ot Pro Sound Labs claims that ‘two
(PZM) microphones - one on each end of the table - would pick up 20 people talking, very easily. It’s
probably the best microphone you could use for teleconferencing purposes. Because of the PZM’s
compact size... the plate-type microphone is easily recessible into any tabletop.”
Our own recommendation for this application would be one PZM for each four to six people, depending on the size of the table.
FIXTURES FILL SANCTUARY WITH LIGHT AND SOUND
I enjoy very much the Application Notes, new product news, and general information exchange that
are coming my way via the PZMemo.
I recently installed a pair of 3OGP [now the PZM-30D] microphones for recording and reinforcement of
a church choir. The microphones were fastened to the choir side of existing five-sided light fixtures.
The dimension of the surface is approximately 9" width by 36" height. The microphones are about 20
feet above the choir and 24 feet into the sanctuary. Results have been outstanding. The music director, pastor, system operator, and members of the congregation are expressing total satisfaction. This
is the third pair of microphones that have been installed in the last 10-12 years, and it is the first time
that everyone is satisfied. The church is the East Congregational Church in Grand Rapids, Michigan
Keep up the good work.
Mel Wierenga, Presiden, ASCOM, Inc., Wyoming, Michigan
PZM GETS INTERVIEWED
Radio Station KZLA, Los Angeles, reports excellent pickup and clarity of sound with two to five people
in interview and public forum programs with the 30GP [now the PZM-30D] mounted on a mike stand.
Although they expressed concern about the price, ‘they discovered that the PZM could replace miking
each person individually and solve their cost problem.
Vince/KW
PZM IN THE MAGAZINES
Just a few items that caught our eye:
An interview with Tim Boyle, recording engineer for Peter Frampton, included an interesting bit on
piano miking, using two C414’s on the high and low end inside the piano, with a PZM taped to the lid,
with the piano closed and covered. Tim seemed impressed with the PZM performance and is quoted
as saying, “They’re good and they’re cheap, too. I think in a couple of years people will find out about
them.” (MODERN RECORDING AND USIC, Oct. 1979) (We’ve got to get caught up with our readingKW).
Joe Tarzia, recording engineer for Teddy Pendergrass, is quoted in an article appearing in the September issue of MODERN RECORDING AND MUSIC (September, 1981), as saying about his mounting two PZM microphones on the angled glass of the studio windows: “There’s an unexplainable
openness to the PZMs. On occasion, I’ve taped PZM mikes to the corner of two walls. which added a
bottom that was lacking in other positions.”
David Morgan, soundman for the Barry Manilow tour in the fall of 1980, writes in the June, 1981, issue
of RECORDING ENGINEER/PRODUCER in great detail about the sound system used for the tour.
For the Manilow piano, Morgan selected a PZM, mounted on Ozite carpet under the lid, and an AKG
451 mounted on one of the cross braces inside the piano. Morgan says: “This combination turned out
to be exactly what we were looking for, It sounded exactly like a grand piano. I rolled off most of the
high end on the PZM, yet retained enough to keep that pleasing percussion quality on the low strings.
The 451 was rolled off all the way up to 700Hz, and I used it for brightness only.”
Morgan also found that by changing the phase relationships between the two mikes. he could produce
the sounds of almost any kind of piano needed. The whole article is great reading, if you can still find
a copy.
STUDIO SOUND (Canada) in reporting on the Los Angeles AES of 1981 (issue of August, 1981) says
of PZM: “(They) are becoming quite popular and are generating a spectrum of reactions.” The editor
goes on to describe the use of PZM in a stereo recording situation using a wedge mounting method,
similar to the ideas we have discussed from time to time in these pages.
The February, 1981, issue of MILLIMETER reviews the PZM mike as“exciting tools that will revolution-
ize sound . . . PZM is useful for recreating normal sounds in normal environments because it preserves the natural sound, or room ambience, while retaining a realistic quality which is perfect for
reproducing sounds as true to life as possible.”
PZM EFFECTS BETTER SOUND
A few months ago I was asked to record some effects for a short film. One of those effects was of a
person cleaning a blackboard. I knew right there that the only way to get the right sound is to use a
PZM. So I rented one from David Andrews, and the results were very good. I have to note here that I
tried to use another mike (RE-15) and it didn’t sound right.
Daniel I. Matalon, Burbank, CA
THERMOPLASTIC MIC REDUCES STATIC AND SOUND DISTORTION
Carbon-fiber filled thermoplastic is the key material in Crown International Inc.’s new Pressure Zone
Microphone.
Designers of the device claim it is the most significant innovation in microphone design in 45 years,
because its materials solve the problems of sound distortion and static interference.
The mike operates on this principle: Near the reflective surface closest to a sound source, there is a
zone in which direct and reflected sound waves are in phase. The mic capsule is placed there.
The PZM is recommended for use in recording studios and on conference tables.
Material selected for the mike is nylon 6/6 with 30% carbon fill, which Crown says helps reduce static
electricity.
Further, the reinforced material offers thin-wall construction while maintaining necessary strength. It
has a modulus of elasticity of 35x10^5 psi, and compressive strength of 29,000 psi. Crown claims the
strength is especially important in instances where the mike is set on a floor — of a stage for instance
— and might be stepped on.
PZM WINS PRIZES
The Crown PZM microphone has been the recipient of two major awards in the field of design engineering during 1981, for excellence in the use of materials.
MATERIALS ENGINEERING. a publication devoted to the discussion of significant new uses of materials in engineered products, has identified the PZM microphone and its engineering staff, headed by
Don Eger and Wayne Royer, as the recipients of its Top Twenty award for imaginative and excellent
use of materials, in this case, of carbon-fiber-filled thermoplastic.
DESIGN ENGINEERING, a publication circulated to over 100,000 design engineers, included the
PZM for special mention in an article devoted to the use of reinforced plastics which are prized for
their high strength-to-weight ratios and their special electrical properties.
Reprinted with permission from MATERIALS ENGINEERING, Nov.1981.
PZM UNDER THE DOME IS SUCCESSFUL
Bill Lewis, in a recent conversation with the editor. reminisced about a choral recording job he and
Dave Johnson (of San Diego Symphony fame) did.
As Bill remembers it, the choir numbered somewhere near 150 voices, accompanied by a small chamber orchestra, which was unusual in being duplicated right to left. As the music from the choir emphasized the right side, only the right orchestra would accompany the singers, and the same effect held to
the left. It was an exciting audio effect.
The miking was further complicated by the fact that the recording was done in a cathedral with a tall
domed ceiling, with the choir positioned directly under the dome.
Bill and Dave miked the group with two PZM microphones, mounted on 2’x2' Plexiglas panels, fifteen
feet high and twenty feet apart. Mike output went to power supply and directly into the tape recorder
(no mixer). The mikes were positioned about 25' back from the choir with the orchestra directly in front
of the singers.
Bill: “We were simply amazed at the fantastic imagery, the clarity of the sound and the extraordinary
balance between choir and orchestra. It was an experience hard to forget, especially when you think
what we may have had to go through if we had not had PZM mikes to do the job.”
“PZMs ARE GREAT MIKES”
I recently released a recording with footstomps called “It Hurts To Be In Love.” I wanted that Four
Seasons sort of sounding clap/stomps with a little army boots thrown in. We stomped on plywood and
I put two PZMs on adjacent plywood baffles. Sounded great!
Just engineered and produced the Plasmatics. I used PZMs to recreate more room drum and bass
sound at my studio, the SCHOOLHOUSE (with a 20 x 26 x 14 room). PZM worked fine on the studio
tracks and was exceptional on beefing up two live tracks for the EQ. The PZMs added a real lower
mid and bottom which is heard on the disc.
We’re currently producing Average White Band, using PZM for Hamish Stuart’s lead vocal sound. It
brings out all the best of his vocal style!
Great mike!
Dan Hartman, SCHOOLHOUSE, New York, NY
STAGE REINFORCEMENT
Jim Brown, BRIDGEWATER CUSTOM SOUND, Chicago, says he found it valuable to mount PZMs
on 3x3 or 3x4 sheets of plastic or plywood and place them on the floor in front of the performer, tilted
up sfightly towards the performer. In a live situation, this does not interfere with audience listening but
picks up a strong, clear signal to feed to the mixer. Jim uses this technique for multi-channel recording
for groups or orchestras and has found it particularly valuable for brass or vibraphones. The improved
sound quality also lets him reduce the level of the performer monitors, since the clearer sound makes
it easier for the performers to hear themselves.
PZM REPLACES CHURCH MIXER
I recently received a call from Bob Hurd, a director for several choirs in Southern California. He was in
a recording studio when I was demonstrating some PZM-6S’s [now the PZM-6D] to the owner and
was impressed. He wanted to know if there was a PZM which he could use with his church choir,
They have 15 voices, guitars, piano, violin and flute in the group. They had previously been using five
mikes to cover everything and without much success.
I mounted a PZM on a 2’x2' plastic panel and placed it on a mike stand, in front of the choir at chest
level. Pick-up of all instruments and voices was excellent. Not only did they buy the mike, but they
sold the Tapco 6100 mixer they had been using and now just plug the PZM directly into the church’s
main system.
Bob Hurd also told a priest at Loyola Marymount University and they have just bought the same configuration for their choir.
Vince Motel, Downey, CA
###
PZM MEMO
August, 1982
Ken Wahrenbrock, Senior Editor
NEW CROWN CLIP-ON MICS
PZM-3LVR
Two new PZM mikes have been added to the Crown line, both clip-on versions.
The 3LVR [now replaced by the CM-10], a redundant mike, has been designed by Crown to be used
particularly in broadcasting situations. The 3LVR includes two separate PZM microphones mounted
on a clip-on bar, 5.0cm long by 1.0cm wide. The mike is available in either black or champagne and
includes separate cabling for each mike, carried in a common sleeve.
The power supply for the 3LVR is also new and includes two separate active supplies with separate in
and out connections for each mike.
THE EDITOR’S CORNER: PZM ANNIVERSARY
A discussion of the Pressure Recording Process by Ed Long and Ron Wickersham at a Syn-Aud-Con
Seminar in the San Francisco area in January, 1978, tnggered the development of PZM’s.
The prototype PZM first saw the light of day in May, 1978, so with this issue of the PZMemo we celebrate a 4th anniversay. From a very primitive beginning with the models roughly assembled, the
acceptance has been phenomenal. The universal enthusiasm and reaction to something quite different by recording engineers in reinforcement, radio and television has been delightful to observe.
When we realize that there has been more than fifty years of exploration, use and study of free field
microphony with much literature including textbooks on the basics of microphone construction and use
even with particular instruments, we realize there are many interesting and exciting research and
writing projects ahead.
Who will explore the best way to mike particular instruments with PZM’s? Who will research the most
realistic symphony or opera recording methods with PZM’s? Who will test and report objectively on
the difference between free field M-S classical recording and PZM M-S recordings?
Who will find the breakthrough to use the clarity of PZM’s with parabolic reflectors for distance recording for sports? The youngster is forty-eight months old and still developing. Can anyone prognosticate
where it will be in another year? Help it grow by sharing what you have learned.
The 3LVR, as with all PZM microphones, is based on all the principles of the Pressure Recording
Process developed by Long and Wickersham. In this configuration, a small precision calibrated pressure capsule is mounted facing a boundary plate. The invention practically eliminates problems
caused by comb filtering and results in remarkably increased sensitivity and reach. The design also
provides a hemispherical pickup pattern, based on the boundary, with no off-axis decrease in sensitivity.
The 3LV, a companion introduction to the 3LVR. is a single-mike version of the 3LVR and is an efficient investment for voice reinforcement in situations where the redundancy of the 3LVR may not be
necessary. The 3LV is also available in black or champagne and can be used with existing PZM “L”
type power supplies. active or passive. or with optional L” adapter into any Crown PZM supply.
Both the 3LVR and the 3LV includes built-in clip which fastens to fabric or any other thin support.
Neckties or lapels are ideal mounting surfaces. Because of pressure-zone properties and sensitivities
of the PZM design, either mike can be mounted under neckties or other parts of clothing with little loss
of signal quality or clarity.
The PZM-3LV [now the CM-10] is now available from Crown inventory, and demo units have been
sent to dealers. The 3LVR is expected to go into production in August, with literature for both units
available at about the same time.
PZM CHALLENGE 1982
We are pleased to devote much of this issue of PZMemo to reporting on the 1982 PZM Challenge
contest which was developed by Crown as another way (in addition to PZMemo) of sharing PZM
technology.
The beginning
On February 1,1982. Crown mailed to all names on the PZMemo mailing list, to all PZM dealers, and
to editors of professional audio magazines a notice of the PZM Challenge, which was actually two
contests. The “Open” Contest could be entered by anyone except Crown employees and their families. The other was a Crown “Dealer” contest, open only to Crown dealers and their employees.
Entrants were asked to submit excerpts from original stereo recordings made using two or more PZM
microphones as the principal pickups.
The categories
Three categories were established in each contest: classical, popular and environmental sounds.
Unfortunately, no entries were received in the environmental category: we can only speculate that
PZM users have been having too much fun recording musical events to pay attention to sound effects.
Prizes were established for each category in each contest, with a grand prize to be selected in each
contest. Provision was also made for honorable mentions to be awarded to those entries which, in the
opinion of the judges, were of more than average interest.
39 entries
The contest closed on May 1, 1982. with a total of thirty-nine entries received. Each entrant received a
T-shirt decorated with a PZM Challenge emblem. The entries were well distributed among dealer and
open, popular and classical.
The judging
Judging took place on May 6, 1982, in a room especially equipped for accurate playback, with the
speakers carefully positioned and equalized. Special care was taken to prevent the judges from knowing whether entries were submittted on cassette or reels. It is interesting to note that no cassette entry
won prizes or honorable mention.
The judges were:
Greg Bogantz, Engineer, RCA Records, Indianapolis. IN. Greg is in charge of disc mastering technology for RCA and has spent many years of careful listening and engineering in the recording field. He
is a graduate of Purdue University.
Michael Stoll, President, Reproductions Technology, Inc., Elkhart, IN. Mike is the founder of RTI, a
manufacturer of industrial reel-to-reel tape recorders, and a recording engineer with several discs to
his credit.
Robert J. Pickrell, Manager, Elkhart County Symphony Association, Elkhart, IN. Bob has been involved with the production of musical events for most of his adult life and is currently in his 13th year
as manager ofthe Elkhart County Symphony Association. He is a graduate of Chicago-Conservatory
College. Chicago, Illinois.
The criteria
The basic criterion for judging was the perception by the judges of the fidelity of the recording process.
Given the musical production and the aims of the recording engineer, did the recording provide a
faithful rendition of what was actually going on during the performance? Music content and the quality
of the performer’s skill were specifically ruled out at criteria for judging.
The judges listened for such qualities as balance, closeness or distance of various performers, mix,
bandwidth, clarity and ambience.
A second major criterion for judging was the degree of creativity shown in the use of the PZM microphones. Entrants were asked to submit miking diagrams along with their tapes: after listening to each
entry, the judges were shown these diagrams.
The scoring was on a scale of 1 to 10 (high), individually by each judge, with scores totaled independently by Crown’s advertising and public relations agency.
The winners
Grand prize and open popular category: David C. Jensen, Sparks, Nevada, for a recording of
BUZZARD’S ROOST at the Hilton Opera House Stage, Reno, Nevada.
Open classical category: Larry Glenn, Eau Claire, Wisconsin, for a recording of the Christmas
Concert at University Arena, Eau Claire, Wisconsin.
Grand prize and dealer classical category: Chet Hall, Canal Winchester, Ohio, for a recording of
the Columbus Symphony Pops Concert, Batelle Hall, Columbus, Ohio.
Dealer popular category: Alfred B. Grunwell, Ithaca, N.Y., for a recording of the Covenant Love
Community Chorus and Orchestra. “Before His Majesty The King: at Calf Audio, Inc., Ithaca, N.Y.
Honorable mention: Tres Virgos Studio (Gerald E. Jabobs, owner) on behalf of Tamarin Productions,
San Rafael, CA, for the instrumental tracks of an A-V presentation prepared for Bank of America.
Honorable mention: Michael E. Lamm, Houston, Tesas, for a recording of the Texas Chamber Orchestra at Galveston Opera House, Galveston, Texas.
Honorable mention: Joe Bidwell of Autograph, Incorporated. Tucson, Arizona, for a recording of “I
Smile (But You Know It Ain’t Easy)” at Autograph Studio, Tucson, Arizona.
Our heartiest congratulations to each and every winner, and our deepest thanks to all who entered the
contest.
BUZZARD’S ROOST (Grand Prize, Open)
The group plays good bluegrass. As this session, the performers were:
Steve Carlson Dobro
Joe Craven III Mandolin
Steve Davis Banjo
Charlie Edsall Guitar
Bob Erlich Fiddle
Julie Smyers Upright Bass
The recording was made on the stage of the Hilton Opera House in Rena, Nevada, on February 21,
1982. Dave Jensen, the recording engineer, had set up plexiglass sheets to form a boundary four feet
high and ten feet long. Two PZM mikes (a 3OGP and a 6LP) [now the PZM-30D and PZM-6D] were
attached to the boundary six feet apart and three feet above the floor. This mike “stand” was then
placed ussstage center (the stage is sixty feet wide by fifty-five feet deep).
The performers then faced the boundary and the back of the stage. A typical placement is shown
below:
Buzzard’s Roost mic setup
The PZM mikes were phantom powered from a Yamaha PM-1000 mixer, panned hard left and right,
flat channel EQ, no effects, into a TEAC 35-2 half-track recorder, 15 ips, dBX encoded. The entry tape
was a copy from thc master.
As the readers of PZMemo can appreciate, this is an unusual set-up. Jensen also decided on one
additional trick that really made this an outstanding recording. The mix during the performance was
physical; that is, the performers moved forward and back to develop the needed emphasis. The mixer,
once set for a performance, was not changed in any way. The judges recognized this creative use of
the PZM mikes and the top-notch quality of the recording. We’re glad he decided to share it with us.
COLUMBUS SYMPHONY (Grand Prize, Dealer)
On the evening of March 27, 1982, Mitch Miller conducted the Columbus Symphony Pops Orchestra
in a performance which included the Dance of the Comedians by Smetana. The place was Batelle
Hall, Ohio Center, in Columbus. The large auditorium (250 feet by 150 feet with a 40-foot ceiling) is in
a multi-purpose structure and is capable of seating over 3,000 people.
Chet Hall, the recording engineer, obtained permission to reeord the concert with the aid of PZM
mikes. He used two PZM6LP’s [now the PZM-6D] mounted on 24' x 30' plexiglass plates, 1/4" thick.
The plates were strung on aircraft cable, twenty feet apart and fifteen feet up over the conductor.
The mic signal went to a Tascam board/D-out to Tascam 35-2B 1/2-track recorder, Ampex 456 tape at
15 ips.
Again the judges were impressed with the realism of this recording and particularly with the good
balance and ambience resulting from the mike placement, which fairly represents an ideal for PZM
miking of orchestras. All of the Symphony’s eighty pieces were clearly heard and accurately positioned.
A CHRISTMAS CONCERT
(Category Winner, Open Classical)
The Department of Music of the University of Wisconsin at Eau Claire presented a Christmas Concert
at University Arena in Eau Claire on December 6 and 7.1980. Larry Glenn was asked to do a recording for the record and elected to use two PZM 3OGP’s [now the PZM-30D] as a selected pair
mounted on the underside of a steel beam near the ceiling. The mikes were approximately 25 feet
above the performers and positioned 12-feet to either side of the conductor. Principal works performed were THE STAR OF BETHLEHEM by Josef Rheinberger and NEW YEAR’S SONG by Robert
Schumann.
Of particular interest on this recording was the excellent separation of soloists. orchestra and choir.
Balance and distance information provided an accurate spatial picture of the performance, ranking this
as one of the best of the entries.
BEFORE HIS MAJESTY THE KING
(Category Winner. Dealer Popular)
Alfred B. Grunwell works for Calf Audio, Inc., in Ithaca, New York. The tape submitted to the PZM
Challenge was a copy of recordings by the Covenant Love Community (producers: Lynn Nichols and
Peter Hopper) for an album planned for release this summer.
The balance of this report is made up of quotes from Grunwell’s notes accompanying his entry, plus
some delightful sketches he made to show us how he used PZM as the principle mike for this recording.
Covenant Love Community (Notes on the Recording)
“Recording was done in as large chunks as possible: i.e., drums, bass, acoustic piano, and rhythm
guitar were recorded simultaneously when possible.
“All choruses and instruments were recorded in stereo whenever possible. The project wanted to be
as ‘big’ and ‘spacious’ as possible.
“Before His Majesty The King” mic setup
“Most effects were added during the mix, including but not limited to compression. phasing, flanging,
doubling, echo, reverb, etc. A dramatic sound was sought but not at the expense of the music or the
message.
“PZM’s were chosen and used whenever possible because of their open, airy sound, Ours is a small
studio by big-boy standards and this helped overcome the problem.
“Baffles, goboes and separate rooms were NOT used in this recording. Hence there is a ‘bleed’ from
the drums onto the piano track, for example, but this was not felt to detract from the feeling. And since
with the PZM’s the pianist could play with the rest of the group at the same time, a more musical
performance was achieved.
“For the ‘Distance’ PZM, it was stuck up an elevator shaft we have, to increase the space on certain
instruments.
“Equipment Used: Board: ADM 3216. Machines: Ampex MMIOOO, ElectroSound ES505. The machines run at 30 ips, Ampex 456 Grand Master, EL +9 level, NO NOISE REDUCTION. The clients
loved the combination of PZM’s, UREI 811 time aligned monitors, 30 ips and no noise reduction. The
master mix is very open and spacious sounding.
“His Majesty” mic setup.
“Other ancillary equipment: Inovonics Dynex, Orban Stereo Synthesizers, Orban Controller, Orban
Parametric EQ, Orban Stereo Limiter, UREI 1176 Limiter, dBX 160 series Compressor, IRPS DDL,
Lexicon PCM 41’s, UREI Little Dipper, AKG BXIO, etc.
“Our mikes included two Wahrenbrock Original Prototype PZM’s (048, 049) and a Crown 6LPB. We
borrowed a Couple of other 6LPB’s for this project. We also used a number of conventional mikes as
indicated on the sketches.”
“His Majesty” mic setup.
Recording Engineers: Alfred B. Grunwell, J. Todd Hutchinson. Mixing Engineers: ABG, JTH with
producers Peter Hopper and Lynn Nichols.
Recorded and mixed at Calf Audio, Inc., Ithaca, N.Y. 14850.
TRES VIRGOS
(Honorable Mention)
The entry submitted by Tres Virgos was recorded as the instrumental track for an audio-visual presentation prepared for the Bank of America.
Jerry Jacob. owner of Tres Virgos. prepared the entry forms which accompanied the tape and included the sketch which says all we need to know about the methods used to achieve the quality
sound coming from Tres Virgos. Note especially the piano concept. in which a PZM is mounted on the
stick, facing into the treble strings. as well as another PZM inside the lid above the far end of the
bass.
Tres Virgos mic setup.
All PZM mikes were 3OGP [now the PZM=30D], and the inputs were mixed on an MCI 528B console
which had been modified with Aphex VCA’s and custom interface circuitry and were recorded for this
performance on an MCI JH-24 16/24 Master Recorder which also had some custom interface circuitry
added. Engineers (record and mix) were Ed Bannon and Robin Yeager, assisted by Robert Missbach.
Producers for Tamatin Productions were Tom Donald and Jerry Jacob.
“I SMILE (BUT YOU KNOW IT AIN’T EASY)”
(Honorable Mention)
This song. written by Ky Fleming and Dennis Morgan, was recorded exclusively with PZM mikes
(except for the drum kit) in early 1981 for BIRC records and remixed br the PZM Challenge in February, 1982.
Joe Bidwell, the engineer, added a comment to his outline: “The disc made from this recording (BIRC
0490) received substantial play on Tucson station KIKX. While the mix was done with AM broadcast in
mind. the record seemed to have more ‘presence’ than other records at the station. I attribute this, at
least partially. to the extensive use of PZM’s.”
The performers and mic techniques are as follows:
Lead Vocalist: Erin Brooks
A PZM 2LV (61138) was affixed to a 2’x2', 1/8" plexiglass plate mounted on a mic stand. Erin worked
about 12" from the mic. (This is a recent overdub. The original 3-81 recording used a 6LP in the same
configuration.)
Drums: Dennis Fridkin
A PZM 3OGP [now the PZM-30D] was placed inside the bass drum, face-up on a pillow damper.
Other mikes were conventional.
Bass: Johnny Lange (Autograph Salesman) A Music Man instrument
direct-in.
Piano: Duncan Stitt
A 31S [now the PZM-30D] was mounted on a 2’x2' plexiglass surface and used 2' from the back of the
soundboard of a Baldwin Hamilton.
Guitar: Don Shipley
A 6LP [now the PZM-6D], on a 2’x2' plexiglass plate, was used 12" from the Gibson “Country Western” (circa 1963).
Strings: Don Demer Quartet
A 31S [now the PZM-30D], mounted to a 2 x 2 plate. was suspended ahove the section on a mike
boom and adjusted for balance. The players sat in a 6' circle: the mic was placed at a 7' height.
Steel Guitar: Rich Brennion
A 31S [now the PZM-30D] was placed on the floor, 12 inches in front of a vintage Gibson amplifier
(circa 1938) with the original field-coil speaker. Rich played a Z-B instrument.
“I Smile” vocal mic technique.
Backing Vocals: Connie Warren, Lucy Billings, Erin Btrooks.
A 6LP [now the PZM-6D] on 2’x2' plate was used as shown in the above photo. Notice that the music
was placed behind the plexiglass.
TEXAS CHAMBER ORCHESTRA
(Honorable Mention)
On the 28th of March, 1982, the Texas Chamber Orchestra played a program of classical music
including Handel’s CONCERTO GROSSO, J.S. Bach’s Concerto in A Minor for violin, Beethoven’s
KONZERT SATZ FOR VIOLIN AND ORCHESTRA, and Mozart’s Eine Kleine Nachtmusik. The
Galveston Opera House, where the performance took place, has a lower balcony whose face is approximately thirty feet from the front of the stage. Michael E. Lamm, recording engineer, was asked to
make a tape for the record and placed two PZM-150’s [now the PZM-6D] on plexiglass plates on the
face of the balcony in what Lamm characterizes as a DIN configuration (see sketch).
Texas Chamber Orchestra mic technique.
The judges noted an exceptional stereo balance and clarity but also a somewhat higher level of audience noise.
###
PZM MEMO
November, 1982
Ken Wahrenbrock, Senior Editor
PZM AS A LAVALIER
Last month, producer Elliot Redpearl and engineer Chris Cassone hit upon a really novel and unusual
way to use the PZM.
During the “Rocky” recording session for Rumpelstiltskin Productions, Cassone and Redpearl decided
that the U-47 they were using on Rocky’s vocals was not demonstrating enough of Rocky’s dynamic
vocal presence. They tried placing the PZM in several different positions, when Cassone finally suggested taping the PZM to Rocky’s chest.
Redpearl and Cassone walked into the studio where Rocky was waiting for instructions. Without
warning, Cassone started to take off Rocky’s t-shirt. As Cassone ran gaffers tape around his chest,
Rocky said, “I don’t believe you’re doing this.”
“I don’t believe you’re letting me,” was all Chris could say.
After a take or two, we found that the PZM was not breathing with Rocky; Cassone then borrowed a
pair of suspenders and taped the PZM to them (photo enclosed). The sound we finally recorded was
rich, deep, and full of life.
The PZM, when used this way (in conjunction with conventional miking procedures), yields more
presence and vocal nuance than any other method we’ve ever tried or heard of.
We’d be glad to hear your comments. Either Elliot Redpearl or I may be reached at the address below.
Sincerely,
Judy Katz
Director, A&R
Rumpelstiltskin
New York, NY
CHOOSING A MICROPHONE
An excerpt from an article In THEATRE DESIGN & TECHNOLOGY, Winter, 1981, by Rollins Brook.
“Our last acoustical type is the Pressure Zone Microphone or PZM. The PZM is a new concept only
three years old. It is probably the first really new microphone principle since the discovery of the
acoustical cardioid in 1936. The PZM doesn’t even look like a microphone. It is a small metal plate
upon which is mounted a small block with an XLR connector in one end. The microphone element (a
condenser) is less than ¼” in diameter and is mounted facing the metal plate with only a few thousandths of an inch space between them. With the element so mounted, there is no such thing as onaxis; all the sounds reaching the rnicrophone will come in scooting along the mounting plate in what is
known as the boundary pressure zone. (For those who would like to know more about the technical
whys and wherefores, Crown, the manufacturer of PZM, will gladly send a stack of literature.)
“For our purposes now, let us consider the product of this new technique. First, the PZM is rarely
mounted on a mic stand. It goes on the floor or on the ceiling or on a set wall or attached to the piano
lid or some other large flat surface. Its pickup pattern is hemispherical - one half of an omni. Most
importantly, it has no off-axis coloration.
“The PZM is still too new for us to know all its capabilities and its shortcomings. We still must develop
proper techniques of use to realize all its advantages. But at this point, three years after its introduction with over 4,000 units in use around the world, it appears that we have a major addition to the
world of microphones.”
ASHLAND, OREGON, SHAKESPEARE FESTIVAL USES PZMS FOR
SECOND YEAR
(See article in February, 1982 PZMemo.)
KSOR National Public Radio Station at Southern Oregon State College in Ashland has been broadcasting the opening night performance of the annual Shakespeare Festival live since 1977. They were
taping the show for later broadcast many years before that. They also make the broadcast available
on satellite for other NPR stations all over the country.
Through the years they have constantly improved their pickup of the Festival so that the listeners can
sense the realism and the crowd ambience. They have also added features like “Stump the Experts”
and introductory music to add to the interest and enjoyment of the radio audience.
last year in an attempt to fill in some of the holes in past years miking and wishing to improve the
pickup for radio audiences all over the country, they tested PZMs. Since the Festival is in an Elizabethan outdoor unreinforced theater, the microphones had to be invisible. PZM-30GPs [now the PZM30D] were used for the stage floor front and 6LPs [now the PZM-6D] were used in several spots. The
reaction of staff and audience was very positive. The articulation pickup of the cast had improved
several orders of magnitude. Reports from other stations carrying the broadcast were highly complimentary.
This year, as they prepared to cover the Festival, they sought to build on last year. They used 6S
cantilevers which were concealed behind posts and scenery to give the added reach of PZM-2 and
PZM-3 formats [discontinued], plus some 2-1/2’s and 2LVs for announcers and music. A special 4-way
was used for the panel presentation.
KSOR is also expanding their studios and will be using PZMs for a weekly children’s program which
they produce and distribute over the 2nd largest satellite translator network in the nation. Many of the
translators are solar powered. Gina Ing is the Director of Resource Development and John Baxter is
Program Director.
KW
PZM TESTED BY AMERICAN RADIO THEATRE
David Krebs, president of the ART, served as recording engineer for a series of tests of the PZM
microphone and as author of the test report. The tests were run to determine “applicability and feasibility of. . . PZM microphones in the recording of human voices and sound effects for stereo radio
dramas.”
In the tests, which were conducted from December of 1981 through March of 1982, PZM-2-1/2s [now
PCC-160] were used adjacent to each other (developing a pickup pattern analogous to the coincident
crossed pair configuration used with conventional mikes). In several of the tests the angle of separation of the two mikes was varied (see sketches).
Krebs reported: “The PZMs seemed to perform quite well. It was noted that the stereo field made the
listener much more aware of the room ambience and size, and that it would be necessary to investigate ways of improving off-mic effects. WKYU-FM recently purchased two PZM microphones. In
getting to know them we have tried a number of configurations for studio and remote use.
In monaural, off-mic is achieved by simply turning one’s head into the dead area of the microphone
being used. With bidirectional ribbon mics or cardioids, this is a simple matter. With PZMs it is necessary to combine physical distance with a motion into the dead area to realize the same illusion of
character motions in a radio play.”
Copies of the complete report will be sent free of charge to station engineers who request it on their
letterhead.
PZMs on PLATES
WKYU-FM recently purchased two PZMs. In getting to know them we have tried a nuber of configurations for studio and remote use.
Recently we decided on 20-inch diameter plexiglass discs on which the PZMs would be mounted for
remote band and ensemble pick-ups. Since we also use the PZMs in other configurations we needed
a quick and safe way to mount the mikes on the plexiglass.
After consideration of a number of alternatives - drilling and threading, double-face tape, etc. - we
tried contact cementing Velcro strips to the back of the PZM plate and the face of the plexiglass disc.
Two five-inch long strips have been cemented to each plate with corresponding strips cemented to
each disc.
The Velcro is holding the mikes firmly, is not bad looking, and makes mounting the mikes a quick and
simple process. The whole process cost about $1.50.
David T. Wilkinson, WKYU-FM, Western Kentucky University
AETNA TELECONFERENCES WITH PZM
COMMUNICATONS NEWS carried a story in its May issue on a new teleconferencing system being
developed by Aetna Life and Casualty, Hartford, Connecticut. Although the system will eventually be
national in scope, its beginning links are between Hartford headquarters and a data processing build-
ing eight miles away. Four rooms, two at each site, are currently in operation, saving the company a
great deal of travel time and expense.
Each room is designed for six people, with a PZM microphone installed on the central wedge-shaped
table for each seat and a seventh mounted on the back wall. The publication notes: “The Aetna system appears to be a success.”
Richard Jackson, manager of teleconferencing and technical communications for Aetna, is quoted in
the article as saying, in part: “If you do decide on teleconferencing in any of its forms... treat the audio
correctly and make your first use a suceessful one. Don’t short-change yourself so your company’s
first move into this technology is a bad experience... do it right the first time.”To which we can only
add, “Amen.”
The Aetna system was also described and pictured in the July, 1982, issue of MANAGEMENT REVIEW, as part of a major article reviewing teleconferencing. The article suggests that designers of
teleconferencing systems need to work closely with corporate managers to make sure the systems
match corporate needs. MANAGEMENT REVIEW also points out that not all conferencing will be
adaptable to electronic interfaces; but where properly designed and used, it can contribute significantly to more efficient communications.
The Aetna teleconferencing rooms have been awarded an “Excellence in Sound” award from Altec
Lansing. Although the PZM microphones are clearly visible in the photos included in the printed brochure prepared by AL, no mention is made of them in the equipment list. Naturally. But M & S Sound
Company, who was contractor for the installation, wrote us a nice letter in which they said: “Through
extensive research we came to the conclusion that PZM was the only way to go in the Aetna.”
Thank you, M&S.
AN ITALIAN VIEW OF PZM SOUND QUALITY
FARE MUSICA, an Italian magazine, recently carried an article on PZM microphones by Darin
Massari. The author reviews the history and development of the microphone in some detail and includes in the last section of his article several ideas on how to use the PZM. Some excerpts:
“The PZM is one of the purest and finest things you ever saw... “Let us now look at the best use one
may make of it.
“Voice: at a distance of 30cm (11.8”), the voice is perfect, requiring no adjustment to meet the natural
timbre; it also carried dynamic forti without yielding in the least.
“Piano: a PZM at 5cm (2”) from the strings gives a beautiful sound indeed, natural, very limpid.
“Guitar: excellent also at 30cm in front of the body, with a very good, natural equilibrium of timbres and
optimum crispness in the highs.
“Good with an electric guitar, placed 30cm away on the floor or farther away with an amplifier.
“Drums: outstanding performance . . . at 30cm in front on the floor . . . optimum presence and an
enviable ‘punch.’
“Cymbals: one of the most natural and subtle you may have ever heard; delicate but cutting, fine and
bright, very well defined.
“And finally, also very good with bongos . . . one of the few to succeed comfortably in rendering this
very percussive sound.”
PZM SOLVES TV RECORDING PROBLEMS FOR HOSPITAL
The Butterworth Hospital in Grand Rapids, Michigan, produces six times a year a TV teaching film
called “Nursing Grand Rounds.” The film is taped in a 327-seat auditorium and involves a panel of
nurses discussing a particular patient whose course of treatment is followed in some detail to help
other members of the hospital staff understand a surgical procedure or course of treatment for a
specific disease. Following the panel discussion, the panel answers questions from the audience.
Richard Buist, biomedical communications coordinator for the hospital, reports that before PZM, the
panel had problems sliding mikes up and down the table, or tripping over too many cords, or losing the
sound as they went to a blackboard to diagram an answer to a question. Audience questions were
also very difficult to obtain on the tape with the usual difficulties involved in passing hand-helds
around, etc.
PZM has solved all of those problems for Butterworth. One PZM mike on the table picked up all of the
presentation and was even successful in handling audience questions. Dick has found, however, that
the audience can he picked up more easily from a separate PZM mounted on a light pole some distance above the heads of the audience, and aimed out at them.
Dick asked us to extend our thanks to Audio Distributors in Grand Rapids for putting him in touch with
PZM, which we are happy to do. Thanks, A.D.!
SOUNDING OUT PZM MICS IN THE THEATRE
We purchased three PZM microphones in November, 1981 for our production of The Sound of Music.
They worked much better than any other mic arrangement.
The only real problem we encountered, and one that should be remembered, is that the amplification
system was not good enough to use these to their full potential. Our theatre is large (1,364 seats) so
to use them the gain had to be quite high, which leads to problems with feedback. I feel that given a
good amplification system with anti-feedback control, these mics will become the theatre microphones
of the near future. Their placement in a production setting is covered fully in the free Crown literature,
and these methods do work. Purchase of the mics includes a subscription to the PZMemo — a useful
publication permitting dialog between Crown and users of their equipment.
Though they will not solve every miking problem, the advantages of the PZM’s appearance, ease of
setup, resistance to physical damage - far outweigh the disadvantages.
Peter Haentzschel, Technical Director, Wayland Baptist University, Plainview, Texas
Reprinted from the THEATRE CRAFTS Magazine, May, 1982.
PZM PYRAMID FOR THEATER USE
In response to Daniel Minnich’s question on the use of the PZM Pyramid (PZMemo, February, 1982), I
have employed several methods in order to obtain fantastic stage reinforcement for musicals. Our
production company just finished a run of the musical, “Grease.” I used three pyramids, two spaced 28
feet apart, the other upside down as a center fill. PZM-6LPs [now the PZM-6D] were used and the mix
was great.
An upside down pyramid placed twenty feet high should provide excellent reinforcement for center
channel fills. We have made several excellent recordings using this method. I would also suggest that
moving the speaker clusters may reduce any ambient interference. Good luck!
Robert S. Yablans, Technical Director, University of Denver Miracle Theatre Company, Denver, Colorado
MORE ON THE PYRAMID
Here from the Editor are dimensions for some of the experimental versions of the PZM microphone
that we have been trying out. We would appreciate hearing if anyone has tried different dimensions or
angles with improved results (or worse! even knowing what not to do with PZM could be helpful.)
The pyramid is made of three equilateral triangles (remember those from your high-school geometry?
Same dimension on all three sides). The simplest way to build them is to have three pieces of acrylic
plastic cut to size and glue them with an acrylic cement along the three sides; the bottom (or top,
depending on where you’re standing) will be open. Remove the cantilever of a 6LP [PZM-6D] and
mount it at the apex of the pyramid, opposite the open end, with the capsule end of the cantilever
pointing into the apex. The cord will come out the open end and can be taped to the outside of the
pyramid to avoid stressing the connection with the cantilever.
I have used both 12" triangles and 18". My own experience has been that the 18" pyramid has better
response and a tighter pickup.
I am currently experimenting with some 36" triangles for recording organ music. Will let you all know
how they work later.
Fig. 1. PZM Pyramid.
PZM-3
My preferred configuration for this is shown in the sketch. Again, the simplest material for construction
is acrylic sheet, but almost any sheet material will do. Note that the cantilever is mounted with the
capsule nestled into the angle.
Fig. 2. PZM-3-12.
PZM 2-1/2 [now replaced by the PCC-160]
I have used both 12" and an 8" version of this style of PZM, which differs from the PZM-3 [discontin-
ued] only in the angle of back plates. Either of these two can be used for stereo pickup such as is
detniled in the report from American Radio Theatre (see elsewhere in this issue).
Fig. 3. PZM-2-1/2.
The 2-1/2 is especially becoming an accepted configuration for front of stage pickup for dramatic or
musical events, since it is directional and does screen out audience noise. Work is continuing with our
staff in California and at Crown headquarters in Elkhart to determine the best configuration for this and
to determine the operating characteristics of the 2-1/2. We will, of course, publish the data as soon as
it is available.
MORE ON DRUM KITS
In a recent recording session at the “Rock Shop,” David Moore and I were experimenting to find an
open, punchy snare sound.
We found a great sound by taping a PZM-6LP [now the PZM-6D] to a “Maxi-Pad” and attaching the
pad to the kick drum beater head. This gave us a great kick and snare balance with good tone for
both. We added 3dB at 125Hz. With a reflective wall behind the drum kit, the entire set was surprisingly balanced.
Fig. 4. PZM kick-drum miking.
J.Paul Hancock, AUDIO I/O, Norman, Okalahoma
A QUESTION OF VIBRAHARPS
Sirs:
... I have invented and am promoting this new instrument called Silver Harp which has no metal resonator tubes but employs a wooden acoustic body in the same way as a piano or guitar...! Have been
wondering how the PZM microphone works if one or two are placed permanently inside the instrument. The main problem with using a regular condenser mike has been that the attacking sound of the
mallet is so overbearing that this idea was not practical at all, but PZM microphone inside the body of
the Silver Harp might solve many problems
Seiji Oshima, Newton, Mass
K.W.:
We are including this letter for two reasons. One, because it is an interesting problem in PZM
microphony but also because it clarifies an important - and frustrating -problem in customer relations.
We would certainly like to be able to send trial PZM microphones to everyone in the world of music
who wants to try them out for one reason or another, but we are sure that our readers understand how
big a problem this would he for us. So our message to Seiji, and to others like him, is to go to the
nearest PZM dealer (we have already sent Seiji his list) and see if you can work out a trial with the
dealer. Our dealers understand that you frequently must try out PZM to be sure it will work for you,
and they may be willing to work out a trial purchase plan that supplies you with the mike you need
without risk to you or the dealer.
Another possibility is for another reader in Seiji’s neighborhood who may already own a PZM microphone to contact him and offer to let him use your mike for his testing. Helping members of the music
industry to learn and prosper together is one of the reasons we publish PZMemo.
PZM USE IN TV
In most PZM applications, the biggest disadvantage has been the noise from lighting scopes, air
conditioning, cameras and people moving off screen. The hemispherical pick up pattern hears everything. So the use of PZMs makes studio discipline to its uttermost a must, especially for the partici-
pants who will have to pay extra attention to paper rattling, finger tapping and what have you. On the
other hand, the phase problems with two or more microphones is eliminated in a fine way. Also, it
seems as if the difference in level of voices evens out in a fine way. Although the PZM picks up noise
from the studio it is a big question whether this noise is more acceptable than the noise generated
from a multitude of Sony ECM-50’s.
When it comes to music productions not much in the TV situation differs from the recording studio
situation as far as ways to use the PZM - almost. But the tight schedules don’t give us too much time
for experimentation. And it is hard to get people to try something new when it is Neumanns and
Schoeps they’re use to. But I’ll push on to make them try.
The greatest use of PZM in television I’m certain of is their use on special occasions. Because of its
physical shape it can easily fit into a decoration. And because of its polar pattern it’s ideal for use
when a sentence is said back-to-the camera too far away for the boom to pick up or the camera
shoots too wide for the boom not to be in the picture or making shadows on the walls.
Roald Thomesen, Bjornekollen 7, I 344 Haslum, Norway
HOW DO I MAKE MY PZM CARDIOID?
My field is film and TV sound recording . . . commercials, documentaries, news, and on oceasion,
feature films.
My particular problem is this: Every once in a while, I am called upon to record, on VTR, a Broadway
show... where absolutely no changes are made in the performance. We record an actual matinee
performance, and I have to get the sound the best way I can with out disturbing the audience . . . or
the performers!
Up to the time I bought the PZMs, I used condenser mics. putting them on short risers so that they
projected about 3" above the stage in front of the actors. Everything was either black, or taped black
so that they were not noticeable. Then I got the PZMs! Problem is that I want to phase the mikes so
that they pick up the performance, and attenuate the noise from the audience.
So my question is. .. how can this be done? I want to make the PZM cardioid and reduce the hemispherical pick up to the front.ONLY!
I have used the mike on commercials where they have performed beautifully in a heavy wind ambience... and where I had to pick up both sides of an interview, where the announcer sat on one side of
a picnic table and the people, on the other... the low profile and the pick-up ability of the PZM is just
what I needed... plus it was windy tbat day, and not a bit of wind noise came through, although it was
obvious because the hair of the women was blowing about, on camera.
Bob Rogow, BOB ROGOW SOUND, Massapequa, New York
Bob - Put clear plexiglass boundaries behind the mic capsule, with the “nose” of the capsule holder
touching the boundaries. Or use a Crown PCC-160, which is a supercardioid boundary mic.
PZMs ON PANELS PICK UP CHURCH CHOIR LOUD AND CLEAR
Sirs:
Please add my name to your list of satisfied users of PZM mikes. As the sound engineer of Christ
Covenant Church (Greensboro, N.C.), I face many difficult problems. Our pastor is a professional
singer and demands quality sound. We are a small church, and every dollar spent must have maximum return.
I use PZM mikes for sound reinforcement, plus using the mix to make recordings. “B.P.” (before PZM),
we used five Shure SM 58s and one 5M57. Two of the 58s were for the front row of the choir, two for
the second (6" platform), and the last 58 and the 57 for the tenor and bass sections on the last tier.
While it did work OK at times, it often caused great headaches. Many times, since the choir members
are not used to working with microphones, they would stand just far enough behind the mikes to be
out of the response pattern. Sometimes whole sections of the choir dropped out. We could also never
get enough gain without feedback and the choir lacked that natural ambience or “mix” that is so important.
After reading about PZMs in MODERN RECORDING AND MUSIC, and picking apart every piece of
literature I could find on PZM, I stuck my neck out and declared that PZM would solve most if not all of
our problems.
After ordering our microphones from Audio Unlimited (they are good dealers for Crown and have been
helpful in every way), we purchased a new mixing board. Trying to sort out a new board and two new
mikes is a story in itself; but after a little practice, good results were easy to obtain.
The PZM mikes are mounted, one on a 4x4 foot Plexiglas panel flown above the choir and slanted to
favor the back rows, plus one on a 3x3 panel on a mic stand for the first row.
Wow! what results. Monitor gain can be run to the point of pain, pick-up is just short of phenomenal,
and blend and ambience are very good. Another pleasant surprise is that our 25-voice choir sounds
like a “cast of thousands.”
The only problem I have had so far is that during a live performance I don’t have enough time to get
my recording mix set properly. During our last performance (the annual Easter program) the PZM
mikes performed so well that I wanted Crown and all their staff to take a welideserved bow. Thank you
for a quality product.
Bill Wood, Sound Engineer/Christ Covenant Church, Greensboro, N.C.
PZM ON HARPSICHORD
Don’t know of anyone in this area with comparable equiment. We have three PZM mikes, using them
principally on harpsichord and voice.
PZM is particularly good on harpsichord, which has a terrific peak as the string is struck. This usually
overloads any other microphone and results in a very scratchy tonality. PZM has a higher tolerance,
and therefore produces a clearer recording.
F.Gardon Morrill, MORRILL RECORDING, Plorence, Italy
###
PZM MEMO
April, 1983
Ken Wahrenbrock, Senior Editor
RECORDING A SMALL CLASSICAL ENSEMBLE WITH PZMs
by Jon R. Sank
(Reprinted with permission from Audio Magazine, March 1983, p. 52.)
Sketch of recent PZM use at “GLEN CAIRN”, Bryn Athyn, PA by Lachln Pitcairn. Musicians from Curtis Institute, formerly of Curtiss String Quartet.
My first hands-on tryout of the PZM in an on-site recording occurred during the Christmas season of
1981 at “Glencairn,” the home of the late Mr. and Mrs. Raymond Pitcairn in Bryn Athyn, PA.
Each year since the residence was completed in 1939, a “Christmas Sing” is held in the Great Rail.
This is a large room with an 80 foot-high ceiling. and up to 800 townspeople attend. Members of the
Philadelphia Orchestra’s brass section play in a smaller room which is joined to the Great Hall by a
large stone archway. The building has handcut stone walls, with teak floors and woodwork.
The PZMs were placed about 8 feet apart on the stone floor of the archway. They did not sound as
good when taped to the (very rough) stone walls of the arch. For comparison, RCA KB-2A “Paintbrush” velocity microphones were “flown” about 20 feet above the PZMs. Each set of mikes were then
connected to identical Tandberg cassette recorders.
Lachlan Pitcairn, son of Raymond Pitcairn and an accomplished amateur musician, supervised the
recordings. He had previously selected the conventional microphone type and placement. For this
“Sing,” however, the contrast in setup labor was great: The PZMs were taped to the floor, with power
supplies hidden in a niche and short cable running along the floor to the recorder. The “flown” mikes
required some human acrobatics, plus long cable runs and balancing transformers at the Tandbergs
to eliminate noise and r.f.i.
The PZM and conventional recordings sounded almost identical in the low and midrange frequencies,
including the same mix of direct and reverberant sound. The PZMs sounded brighter in the highs, but
the velocity mikes had falling response above 5kHz. I found it surprising that the microphones placed
on the floor could sound similar to those overhead.
1983 PZM CHALLENGE CLOSES MAY 1 WITH MANY ENTRIES
RECEIVED
The 1983 PZM Challenge is now entering the judging phase, with May 1 as the last postmark date for
entries.
According to Gerry Barclay, Crown promotions manager, a number of entries have already been
received, with judging scheduled for mid-May. Results of the contest wiil be announced in early June.
The 1983 Challenge is being conducted in a similiar fashion to the 1982 competition, with entries
allowed in two separate contests: one for Crown dealers and their employees, and one for all other
PZM users. Barclay emphasized that “this seemed the only fair way to provide some separation between PZM-experienced dealers and their customers.”
Entrants were asked to submit tape excerpts from original stereo recordings which were made using
at least two PZM microphones as the main pickups. The tapes are being judged on fidelity of the
recording process, overall sound quality and creativity in PZM use.
In addition to the tapes, entrants are asked to submit miking diagrams and other suitable sketches or
photographs. These enable the judges to evaluate more closely such variables as mike-to-performer
distance, ambience, mixing and balance. In the judging process, these plans and sketches are evaluated after the judges have first listened to the tapes and recorded an initial score.
Entries will be judged as either classical, popular or environmental with a prize in each category and a
grand prize in each contest.
Category prizes will be a pair of PZM microphones, with the model to be selected from the expanding
line of new PZM mikes introduced in 1982-83.
Grand prize winners will also receive a Crown home audio system consisting of an FM2 tuner, SL2
preamp and PL2 power amp, all in a handsome walnut cabinet.
The judges may also elect to award honorable mention prizes of $50.00 to entries deemed worthy.
STUDIO PZM USE
Well over 100 recording studios in the U.S. are now using PZM microphones.
PZM SHOWS OFF FOR RINGLING AND ICE FOLLIES
As reported in PRO SOUND NEWS, April and SOUND AND COMMUNICATIONS, April:
Future Sounds, Inc., of Weston, Connecticut won contracts to supply sound systems for Ice Follies,
and for Ringling Brothers Circus for their 1982 seasons. In both systems PZM mikes were used to
pick up live music.
Doug Donahue, president of Future Sound, said of the Ringling system, which includes 14 PZM mikes
which streamlines the orchestra setup, “The greatest show on earth now has the greatest sound on
earth.”
Donahue reports to us by phone that the Ringling bandmaster had been experiencing some difficulty
in obtaining consistent sound as the circus traveled from city to city. Mike setups always seemed to be
difficult to duplicate, with noticeable differences in sound.
Donahue solved the problem by drilling small holes in the PZM plates and fastening them to the
band’s music stands. Donahue says the bandmaster is delighted, the sound is consistent, “and the
band plays on.”
PZM ON DRUMS
“The seemingly non-restricted or non-confined frequency spectrum that the PZM has gives it the
versatility that I have longed for in a microphone. The brights of the PZM make it the perfect overhead
mike for a drum kit, while the rugged bottom end gives the user a perfect drum kick mike. With the
time difference between the direct and reflected sound waves being so minute, this in-phase perfection seems to have no degree of distortion. I have never been more pleased with a microphone.”
Christpher W. Eagan, Freehold, NJ
CANBY ON BACH - AND PZM
“There’s always something new for me at the Oregon Bach Festival, where I’ve been taking myself
each year after the long Eastern winters. In 1981, you may recall, I discovered an interesting array of
PZM microphones.
“This year, somewhat to my surprise, the PZMs occupied different positions; the main miking was
standard.
“The smaller pair of PZMs took on the hanging job; at half stage, facing backwards to pick up the
chorus which sang on risers directly behind the orchestra. These mikes cope beautifully with the
severe transients generated by loud choral forces; the wrong-side, non-response of the half-omni
pattern cuts down audience noise and the flat response out to wide angles gives a sharp, clear definition in stereo. I suspect there is no better microphone anywhere for chorus.
“I discovered the larger pair of PZM squares in a brand-new location, hung far apart a few feet out
from the rear boundary. So — PZMs for ambience? Good idea. Very wide angle, low distortion at the
ambient sides and, again, minimum audience pickup from the rear. In one concert I got to sit about 10
feet behind one of these and found myself viewing the entire concert straight through the mike, like a
large edgeless plate glass window.”
Edward Tatnall Canby, Reprinted with permission from Audio, November 1982.
PZM REVIEW
Our thanks to Jon Sank for a detailed and thoughtful review of PZM microphones in the March 1983
issue of Audio magazine (see excerpt elsewhere in this issue on the “Glencairu” recording). Well
worth tracking down and reading.
MORE ON DRUM MIKING WITH PZMs
“I use a PZM for the overhead on the drum kit. But I don’t use it just for cymbals, I use it for high hat,
all rack toms and the cymbals. I now use just three mikes in the kit. A 421 for kick, a 57 for snare and
a PZM. Also very cost effective because it replaced four mikes I had been using. The PZM is mounted
on a 1-ft x 1-ft plexiglass plate positioned just to the right of the drummer’s head. This also makes
sure I hear what the drummer hears. Even though I use the PZM with a five piece rock & roll band,
leakage is not a problem because the leakage is not off-axis coloration. What leakage there is doesn’t
sound bad.
P.S. Drums sound great too!”, Rande Ferguson, SECO LABS INC., Omaha, NE
PZMs FOR SOUND EFFECTS
“I am using the PZM-31 [now the PZM-30D] for recording sound effects for use in film and television
sound tracks. I use it on everything from church ambience to car crushers. I have had good results so
far and look forward to using it more.”
Fred Brennan, Sound Editor, MASTER’s WORKSHOP CORP.
NPR USING PZMs
We have just received a copy of the press kit distributed to NPR stations across the country from
KSOR-FM, detailing the events of the OREGON SHAKESPEAREAN FESTIVAL, which is produced at
Southern Oregon State College, Ashland, Oregon.
All of the releases mention KSOR’s use of PZM microphones for broadcast pickup, in a new sound
system designed by Ken Wahrenbrock. Reports from participating stations indicate the sound was the
best ever.
We hope to have photos and more details from KSOR to explain exactly what they did, in a later issue
of PZMemo.
STILL MORE ON PZM DRUM MIKING
“On a recent album project we found the ‘standard’ bass-drum technique didn’t work. So, in conjunction with a Sennheiscr MD-421, we added a PZM mounted to 3’x4' Plexiglass plate angled out at the
top slightly. Between the 2 mikes (50% each) we received the kick impact we were looking for.”
“Thanks! They’re great on most everything and perfect for many uses auditoriums, overall drums,
etc.”
Rodger A. Bliss, RIVER CITY STUDIOS, LTD., Grand Rapids, MI
PZM FOR HARPSICHORD
“I have recently purchased one of your PZM-6LP microphones [now the PZM-6D] for use in soundreinforcement situations where the normal volume of my harpsichord is insufficient to cover the acoustical environment in which I am playing. I also own Sennheiser and AKG microphones (dynamic and
condenser), and I find that I get much better results with PZMs.
“In most situations I play harpsichord while my wife plays Baroque flute. She does not enjoy playing
into anything of fixed position (like a microphone on a boom stand), and so I have experimented with
my PZM-6LP mounting it to a strap around her neck in such a way that the electret capsule rests
approximately six inches under her chin. We seem to get pretty good results doing this, although we
have yet to test it in the concert situation. The little booklets sent with the PZM-6LP refer to PZMs of
contrasting colors and mounts, and I am hoping you might send me a copy of any illustrated brochure
you may have available. One of the things we are considering is mounting a gold or silver capsule in a
necklace of some sort that would largely conceal the microphone and wire. I would like to know if this
is a viable solution to reinforcing the Baroque flute (box wood), and I would also be interested in
learning of any alternate solutions you would care to propose.
“Also, I wonder if you feel the results obtained in the recording situation with the PZM are on a par
quality-wise with results using a Neumann U-87 or AKG C414EB with these particular instruments.
Perhaps even the careful mixing or blending of the two different types of microphones would produce
pleasant results. I am interested in your views if you have any to share.”
Gilbert L. Blount, Director, USC EARLY MUSIC ENSEMBLE
AUDIENCE MIKING WITH PZMs
“While mixing a live performance on radio station KWJS in Dallas, I realized that the incredibly small
room we had to work in was going to sound tight and squashed. I quickly reached into my trusty bag
of tricks and pulled out a couple of PZMs, taped one to the ceiling and one to the control room glass,
and ran both through a digital delay and a touch of echo. The 12 people in the audience sounded like
a hundred and the performance of recording artists Tom Autry never sounded better. I left the PZM
mikes on throughout the performance. The radio station staff said it, was the best live broadcast in
their history, thanks to PZM.”
Randy Adams, SIERRA RECORDING, Fort Worth, TX
RECORDINGS DONE WITH PZMs
“Not A One” Vinnie Golia, Alex Cline NW0I07
Woodwinds, drums
“Slice Of Life” Vinnie Golia Trio
Alex Cline - drums
Roberta Miranda - bass
Vinnie Golia - woodwinds NW0I08
“Gift of Fury” Vinnie Golia Quintet same as above w/
Wayne Peet - piano
John Rapson - trombone NW0I09
“Down-In/ness” Wayne Peet - piano NW0III
All records are on the Nine Winds Label with Bruce Bidlack as engineer and Nels Cline as producer.
Source: Vince Motel
MIKING INSIDE A TOM TOM WITH A PZM-2LV
Holding fixture for PZM-2LV
Richard Stevens of Nashville, Tennessee tells me of an accessory he used to mount a PZM 2LV [now
the GLM-100] inside a tom tom (see diagram). Because of the PZM’s ability to handle up to 150 dBSPL, the mike can be mounted right inside the drum and moved from side to side to find the “Sweet
Spot.” Richard is interested in showing his device in the PZMemo.
J. P. Bachman, Crown Project Engineer
PZMs NOT SENSITIVE TO MAGNETIC FIELDS
John Bachman, Crown PZM Project Engineer, notes that the PZM is particularly valuable if you are
contending with strong ambient magnetic fields (especially found in broadcasting applications).
Since PZM mikes do not have coils, they are unaffected by most magnetic fields.
PZM PYRAMID DIMENSIONS
“We need help. Some of the ideas written in the PZMemo are hard to visualize. I need pictures or
drawings of the pyramids. If you have plans for the pyramid setup can you forward a copy of me?
“PZMs work well with band and high school students but little kids are a problem. We push gain as
much as possible but we get feedback. Where should you place stage monitors when using PZMs at
front of stage? Is there a particularly effective way to use PZMs for 1) Plays , 2) Choral groups, 3)
Band (horns) and 4) School Board meetings. I’ve tried them for all those situations and have mixed
results. I want to find what I’m doing right/wrong.”
Enrique K. Ochart Jr., Auditorium Director, SAHUARITA SCHOOLS, Sahuarita, AZ 85629
(The enclosed set of questions are excellent and much of the requested information can be found in
past issues of PZMemos. Refrrences and additional information is provided here.)
A. A picture of a PZM pyramid is in the Crown Boundary Microphone Application Guide. The larger
the size the better the directivity at low frequencies, and the more rejection toward the back of the
microphone.
In addition, here’s a photo of the new Crown PZM-2.5 [now replaced by the PCC-160].
PZM 2.5 directional PZM microphone.
B. The large plate mikes using panels of sizes 2’xl’, 3’x3' and 4’x4' work very well when flown either by
stand or from overhead. I use 1/8" plexiglass or polycarbonate for the 2’x2' and 1/4" material for the
larger ones. Mount the microphone plate 4" off-center for a smooth response. Orient the plate so that
the hemispherical pattern picks up the group, solo, orchestra or ambience you desire. Remember that
the back side of the microphone has very high rejection especially at high frequencies and placement
may be made to reject audience, air conditioning, room ambience, other instruments or speakers.
C. When using 2.5s on the stage there will be excellent rejection of monitors, if large enough plates
are used, and monitors are placed behind the plane of the microphones.
1. The Boundary Mic App Guide mentions the use of PZMs for theater. I suggest 2.5 x 8" or 12" for
the stage front. I use 3 to 5 of them depending upon width of stage and age of cast. I use 1 or 2 pyramids upstage flown in the borders if they are needed. Many times the reach of the downstage 2.5s will
cover, since they reach 25' if the cast projects at all.
2. Choral groups may be miked several ways:
a. 2.5s on the floor. 2.5s on short stands between the choral group in the rear and orchestra in front.
b. Flown large plates in several different configurations. The size of the plates depends upon size of
group, available space for mikes, types of stands available or facility for hanging mikes.
c. Pyramids have been used for each section of a choral group so that some sections could be
assisted more than others when stereo is needed.
d. Choral groups for stereo broadcast have been grouped around two PZMs back-to-back on a 2x2'
plate. Soloists merely moved in closer to a mike and then backed out to the group as required.
3. Band, orchestra and/or sections will find 2.5s, plates and simple standard PZMs all helpful depending upon need. The San Diego Symphony brass section was reinforced by a single 2.5 x 12".
4. School board meetings: If you are merely recording the meeting for a record and secretarial assistance, then one or two 6LPs, 6Ss, 30GPs, or 31Ss will cover large boardroom tables [now the PZM30D and PZM-6D]. If there is a need to amplify the discussion for large open-board meetings, then
2.5s [now the PCC-170, PCC-130 or MB series] will assist you to increase gain and reduce feedback.
I reaffirm that a basic experimental stance is the fundamental requirement to learn PZM microphone
technique. Thank you for the good questions.
Ken Wahrenbrock
###
PZM MEMO
October, 1983
Ken Wahrenbrock, Senior Editor
PZM CHALLENGE, 1983
by Bruce Bartlett
Forty people accepted the PZM Challenge. It was the second annual contest comparing original
stereo recordings that used PZMs as the main microphones. The Challenge is divided into an “open”
contest, which can be entered by anyone except Crown employees and their families; and a “dealer”
contest, for Crown dealers and their employees.
Three categories are established in each contest: classical, popular, and environmental. Category
winners receive their choice of a pair of PZMicrophones. Grand prize winners also receive a Crown
home audio system consisting of an FM-2 Tuner, an SL-2 Preamplifier and a PL-2 Power Amplifier, all
in a walnut cabinet. Honorable mentions - entries of more-than-average interest - receive a fifty-dollar
certificate applicable towards the purchase of a PZMicrophone.
Judging took place on May 6, 1983. The judges had long experience in critical listening. They were:
Dr. Clay Barclay, New Product Manager, Crown International. Clay is also a former high-end audio
retailer and recording engineer.
Charles Brown, free-lance recording engineer, Philadelphia, PA. Charles has recorded, among other
clients, the Philadelphia Orchestra and the Delaware Symphony.
Bruce Bartlett, Microphone Design Engineer, Crown International. Bruce has also worked as a recording engineer, musician, and audio journalist.
A judge’s viewpoint
After patching in all the various types of playback equipment (thanks to Dennis Badke of Crown), we
settled in for a full day of listening to forty-five recordings. Listening was done over a pair of UREI 813A time aligned studio monitor speakers.
On separate forms, we scored each entry on a scale from 1 to 10, both for the overall sound quality
and for creativity in the use of PZMs. We didn’t know who had recorded each entry.
It quickly became apparent that the recordings spanned a wide range of quality. Some entries were
easily ruled out because of noise, distortion, audible compression, or poor frequency response. Note
that these are defects of the recording equipment, not the PZMs.
Most entries were good. They had no serious faults, but often were not exciting as demo material. On
the other hand, a few entries (such as a rock recording by George Pappas) were very impressive for
their clarity, frequency range, naturalness, ambience, balance, and so on. They lost only by default to
the top entries.
The judges’ scores were entered into a computer, which averaged the results and indicated the winners.
One observation became clear: HOW you use the microphones and recording equipment) is just as
important as what microphones you use.
As a judge, there are a few hints I think would be helpful to anyone contemplating entering the Challenge next year:
Find material that is exciting, with extreme highs and lows and a wide dynamic range so that it demonstrates the full capabilities of PZMs.
Get the finest reproduction on tape by using good equipment. Noise and distortion should be inaudible
and no overall compression should be used.
Avoid cassettes if possible. They give lower overall quality. Find a venue with good acoustics.
Use PZMs in unusual ways, and remember to include specifics about placement, etc. with your entry.
Otherwise, judges assign an average score for creativity.
The winners:
Grand Prize in the Open Challenge, Popular Category:
Robert Missbach, Tres Virgos Studios, San Rafael, California;
for a recording of a “multi-image soundtrack” for Westamerica Banks, performed by the Tamarin
Session Players.
Winner in the Open Environmental Category:
David J. Harrington, Casper, Wyoming; for a recording of a basketball game in the Casper Events
Center.
Winner in the Open Classical Category:
RBH Audio Inc., Brooklyn, New York; for a recording of the National Chorale Soloists in St. Peter’s
Church, Citicorp Center, New York.
Honorable Mention, Open Classical Category:
Andrzej Lipinski, Hollywood, California; for a recording of the Radio and TV Chamber Orchestra of
Poznan, Poland, performing in Poznan University Hall.
Dealer Challenge
Grand Prize in the Dealer Challenge, Popular Category:
Alfred B. Grunwell and Todd Hutchinson of Calf Audio, Inc., Ithaca, New York; for a recording of Don
Hale and Dazz (featuring Lesly Giscombe).
Winner in the Dealer Classical Category:
Richard Menasco, Tallahassee, Florida; for a recording of Manuel Ponce’s Concerto for Guitar, performed in the Tallahassee Civic Center.
There were no entries in the Dealer Challenge environmental sounds category.
Thanks to everyone who took up the challenge, and congratulations to all the winners. Let’s discuss
each winning entry in detail:
Multi-image Soundtrack for Westamerica Banks Grand Prize, Open Popular:
A variety of instruments contributed to this unique, highly impressive recording of the Tamarin Session
Players, directed by Peter Adams.
The production was created in April, 1983, at Tres Virgos Studios, a state-of-the-art facility in San
Rafael, California. Mixdown engineer Robert Missbach supplied us with studio layout sheets for the
session:
Fig. 1. Studio layout for Westamerica Banks session.
The recording is a montage of pieces of folk and popular music. Gordon Lyon recorded about 30
seconds each of different musical material, such as bluegrass, jug band, and bagpipes. In the
mixdown, Robert crossfaded from one musical segment to another. The effect is a continuous change
of aural perspectives.
The microphone setup was unusual. Two Crown PZM-3OGPs [now the PZM-30D] were taped together along one edge of their plates, forming a “V.” This was used as a near-coincident stereo pair.
The two microphones were on mike stands about 5 feet high and were angled 20 degrees apart. The
musicians were grouped around this stereo array. To control the balance between the instruments, the
musicians stood at various distances from the microphones. Thus, a true stereo recording of the
ensemble was made onto two tracks of the 2-track recorder. This setup was used for each of the
different musical ensembles contributing to the sound track.
During the 24-track mixdown, Robert segued the 2-track stereo recordings as the mix progressed,
crossfading from one musical “ambience” to another. Although 30 seconds of each musical piece was
recorded, only about 5 seconds of each was played during mixdown. Robert says that no automation
was used - only “ten-finger digital.” It was a difficult mix, but tastefully done.
Some other instruments were covered individually. The staff normally picks up grand piano with a
PZM-3OGP near the short stick and a PZM-31S [now the PZM-30D] on the underside of the lid. Flute
and harmonica were covered with a 3OGP on a stand.
The judges were impressed with the natural stereo perspectives, the clear and spacious sound, and
the imaginative production.
Basketball Game: Winner Open Environmental
This recording transported us right into a CBA basketball game at the Casper Events Center in
Casper, Wyoming, February 6, 1983. Engineer David J. Harrington provided us with the following
information:
The PZM pair was mounted on either side of a 4' by 8' sheet of masonite pegboard. The microphones
were mounted at the top of the pegboard by using a C-clamp to hold them to the masonite. The whole
assembly was suspended over center court, 29 feet above the floor, such that the 8' length divided the
court along a line between the two baskets (see diagram).
Fig. 2. Basketball game miking.
This arrangement permitted the stereo channels to be summed for mono broadcast. It provided maximum stereo separation for the audience sounds but little separation for the players. The house sound
cluster was centered on the same axis as the microphone setup, so the announcements through the
house system were heard in mono.
The judges clearly heard the ball dribbling and shoes squeaking. The recording had a great sense of
stereo ambience, with opposing audience members yelling on both sides.
The National Chorale Soloists
Winner, Open Classical
This polished ensemble, directed by Martin Josman, was recorded February 16, 1983, in St. Peter’s
Church, Citicorp Center, New York. Engineers from RBH Audio mounted two PZM-6LPs [now the
PZM-6D] on 30" by 32" acrylic panels, arranged at a 110-degree angle and rigged 20' above the fourth
row of seats, angled at the performers. No other microphones were used.
The ingenuity of this setup earned it high scores. The stereo imaging and tonal balance were natural;
the recorded ambience was spacious.
Radio & TV Chamber Orchestra of Poznan
Honorable Mention, Open Classical
This is a beautiful, near-flawless recording, made in Poznan University Hall in Poland by Andrzej
Lipinski in 1981. It was recorded for Polish radio and TV in Warsaw.
Two PZM-3OGPs [now the PZM-30D] were placed in a spaced-pair configuration, and ambience
microphones and spot microphones were added.
The judges were impressed by the spacious hall acoustics, the appropriate perspective, the clarity,
and the sharp center imaging.
Don Hale and Dazz
Dealer Grand Prize, Popular
Recorded at Calf Audio Inc., Ithaca, New York, in 1981 through 1983, this entry was tops in creative
use of PZMs as well as sound quality. It was made by Alfred B. Grunwell with Todd Hutchinson assisting. The PZM usage was as follows:
[Note: Current PZM models are PZM-6D and PZM-30D.]
Kick drum - PZM-6LP
Grand piano - Two Wahrenbrock prototype PZMs on the underside of the closed lid.
Electric guitar - PZM-31S for room ambience.
Acoustic guitar - Stereo pair of PZM-31s taped to a wooden door.
Vocals - PZM-315 a few feet away (for “air”) in combination with standard microphones.
Horns - PZM-31S at a distance for blend, in combination with standard microphones up close.
French Horn and flute - PZM-31S at a distance, in combinationwith standard microphones up close.
Don Hale, the writer, arranger, producer, keyboardist, and band leader, was “extremely pleased with
the PZM performance, because it allowed him to hear his arrangements very articulately.” The judges
thought the recording was sleekly produced; very clean, clear, and natural.
Manuel Ponce’s Concerto for Guitar
Winner, Dealer Classical
Richard W. Menasco made this skillfully multi-miked recording at the Tallahassee Civic Center on April
4, 1983. It was mastered on a Technics digital audio cassette recorder. The setup, which earned high
points for creativity, is shown below:
Fig. 3. Microphone setup for Manuel Ponce’s “Concerto for Guitar”
Although the recording lacked hall reverberation, the balance of the multi-miked orchestral sections
was well done. To my ears, the solo acoustic guitar sounded a little too close, out of perspective with
the rest of the orchestra. But that may have been an unavoidable side effect of achieving adequate
isolation on the guitar microphone. Altogether a fine job.
We appreciate the efforts of everyone who accepted this year’s PZM Challenge.
ZAPPA PRODUCES BALLET ALBUM WITH LONDON SYMPHONY
Like to solve problems? Consider these. Arrive in London to record a music project that has been
developing since 1975. The leased hall for the recording with the London Symphony (107 musicians)
is too small. An immovable motion picture screen about eight feet from the rear wall (which the leasing
agent forgot to mention) makes the room even smaller. It is also too noisy, and all the other major
concert halls are booked.
Frank Zappa faced this as he arrived last January in London to record the ballet music he had been
composing for the last eight years. He finally found space in Twickenham Studios, using a sound
stage where the “007” movies had been shot. It was rather dead, which made it difficult for the orchestra but provided dry tracks for better mixdown and fmal editing. The music was also presented at a
live concert at the Barbicon. The recording effort included enough music for a second record that will
be mastered some time in the future.
Frank has used PZMs for a number of years. He has experimented with them for instrument and vocal
pickup from serious music to just having fun with their unique qualities. As he prepared for this project,
Frank had Thom Ehle, one of his engineers, contact Vince Motel of Wahrenbrock Sound to check out
some new prototype PZMs. Vince took several models to The Utility Muffin Research Kitchen, their
recording studio. Frank and Mark Pinske, his recording engineer, tested them and wanted to explore
PZMicrophony more. I visited the studio with Vince and we talked about microphone placement and
instrumental pickup. They then proposed the PZM complement they wanted to take with them to
England. The details were then worked out with Crown and the plastics fabricators to assemble the
quantity desired.
Frank chose to take many of the traditional microphones with him also and had arranged for the
remote recording van to have many of them available, including a Calrec Soundfield mike. As they
prepared for the recording session, Mark had 90 minutes to place the microphones after the stage
crew placed the stands and chairs. He set up the microphones as they had planned with PZMs for
strings and some percussion, and regular mikes for many of the instruments were set up in the usual
way. As the rehearsal started and he checked each mike on the “solo buss,” he found such vast
differences in pickup quality that at each break he was scrambling to replace as many other mikes as
he could with PZMs.
Due to the nature of the acoustics in the new venue and the size of the orchestra, PZMs became the
overwhelming choice for this job. Because there were not quite enough PZMs available to use them
exclusively, a few AKG 451s and an RCA ribbon mike were left in the setup. The hall, the musicians,
the timing, all demanded a quality of microphone pickup that would lay down tracks for extensive
editing work with little loss of quality and minimum noise and leakage. According to Zappa, this record
could not have been made without PZMs, the Sony PCM 24-track digital recorder and the Lexicon
programmable reverb unit. The recording studio in London turned out to be very dry and the Lexicon
unit added the needed richness. And the thousands of edits for the final mix were humanly possible,
Zappa says, only because of the outstanding features of the Sony recorder.
Here are some details on the miking.
STRINGS: These were miked with several different PZMs. The violins and violas were miked with 12"
dishes on boom stands overhead, one dish for each two instruments. The cellos were miked with 2.58" between two instruments at the base of their music stands on the floor. This was just right; the 2.512" picked up too much floor noise and emphasized the box sound. The string basses were miked
with 2.5-12" for each two at the base of their music stand. These picked up the lowest strings with
clarity.
BRASS: The eight French horns were miked first with U47s, but had too much leakage even with the
mikes in the cardioid position, so a change was made to a plate PZM on a barrier behind them. The
French horn players don’t like a boundary behind them because it gives them bad reflections. If you
get underneath them they don’t sound right either, because the players don’t hear themselves that
way. The French horns really sound best with an indirect pickup. Pinske finally put the 31S on the
back barrier and a dish overhead and combined the two. It was an indirect plus an attack sound that
was the best French-horn sound ever.
TROMBONES: Final pickup was two flat-plate 31S’s [now the PZM-30D] on stands facing the
“bones,” but far enough away to get some distance, placed lower than the direct line out of the bell.
The direct sound gave too much attack, too-abrasive a sound, too much initial horn-bell sound. A
microphone hears like your ear. If you put your ear right in front of a trombone, it’s too bright. You want
to put the PZM at a spot where you would want to hear the “bones.” The indirect sound is more pleasing. When you move off-axis, the hot spot of the bells blows past the PZMs. If you lower the PZMs,
they work great. If you raise them, you begin to get cymbals, etc.
WOODWINDS: A dish overhead picked up the flutes and clarinets very well. For bassoon they used a
wooden boundary with a 6S placed behind the instrumentalist. They would also use a 2.5-12" in front
on the floor if there were enough channels. The solo clarinet was miked with the same dish that was
used for the harp at other times.
HARP: The dish was mounted on a low stand and angled downward toward the sounding board when
the harp was tilted back into its normal playing position. The dish can be moved back and forth a mere
4" and change the pickup of the harp and sometimes lose the low register. Placement is very critical.
Pinske says, “I found a spot that was so beautiful!”
PERCUSSION: With the tympani Mark started with a regular mike. As he soloed that mike he could
hear the whole orchestra, so he exchanged it for a plate PZM on 4' x 4' plexiglass and set it up between the tympani and the other drummers. His comment:
“The amount of rejection as compared to the other was phenomenal. I got mainly tympani, and, when
he wasn’t playing, I got very little leakage.” One of the five percussion sections was picked up with a
2.5-12". Gong sounds were very live. Bells were right there in the control room. Two PZMs were finally
used over the drums, and the stick sounds on the snares and toms were exceptional. PZMs also
worked well for handheld percussion instruments like gourds, maracas, whistles, shakers, scrapers,
etc. Pinske used clip-on PZMs for several small items like castanets. For solo percussion instruments
like vibes, marimba, glockenspeil and xylophones, since they were all together, Frank finally used two
31S models [now the PZM-30D] on overhead booms oriented down for stereo pickup. They really
picked up the mallet work.
Problems and Benefits of PZMs
Both Frank Zappa and Mark Pinske shared reactions to the use of PZMs in a project such as this.
Zappa believes that there are some real problems in using PZMs. When musicians walk in and see
the plastic dishes, they laugh, since they think plastic mikes will sound plastic. They are used to large
heavy metal microphones. If they can see through the microphone, they don’t take it seriously. They
also don’t look out for them when they are on the floor, since they can barely see them. The small
cable also reduces the rugged image and stability of the microphone. PZMs thus create problems for
the producer since he has to spend time in interpretation and extra motivation for the orchestra to do
its best in spite of its original humorous image of the microphones. Pinske emphasized that the use of
PZMs requires some explanation to the musicians since many of them had never seen PZMs before.
When they understood it was a new type of microphone and that it had some very distinguishing
characteristics, they kidded about it, but were cooperative and interested.
Another problem is the PZM’s extraordinary sensitivity and the musicians’ awareness of them. Every
time they breathe, move their feet or diddle with their instruments, the sound gets on the tape. A reed
player sucking his reed to keep it moist during breaks can be heard.
Zappa told me that they learned a great deal about plate PZMs on flat boundaries and what they
would do, finding that they are more forgiving than many traditional mikes. The more they tested them
the more they realized that PZMs do react much like the human ear. For instance Pinske would just
walk around until he found a spot where an instrument sounded right, put a PZM there and nine times
out of ten, the sound in the control room was just like it was out there next to the instrument.
They found that when they recorded with PZMs, they needed very little EQ. They might have to cut
one or two spots, but they could lay tracks and then EQ for effects on mixdown as they desired. They
also could make the recording dry enough so that reverberation could be added in the mixdown.
Pinske found to his delight that “In an out-of-phase condition the PZM is the best microphone I’ve
found on this planet to maintain the stereo image. It is unbelievable on low frequencies.” Pinske put
them back-to-back on bass drums and found them to be less than 15 degrees out of phase. Traditional microphones would be at least 90 degrees out of phase at 3340 Hz. Pinske believes that PZM
mikes keep a better stereo image and pass it on to the lacquers.
Frank Zappa’s reaction to the PZMs he used was very positive. He said, “My goal is to get as much of
what actually happens, soundwise, onto a record as I can . . . in spite of the laws of physics and
manufacturing. In a project this expensive, to put your entire trust in one specific kind of technology
and have it pay off is extremely gratifying. We could have played it a lot safer and done it a different
way, but I don’t think that I could have gotten the same results. There is no way we could have gotten
the sounds on these tapes without PZMs.”
PZM Dish prototypes
The new prototype called the “dish” has exceptional qualities that Mark Pinske utilized to get the
close-miked pickup he needed and to provide the isolation that was also necessary. By tilting it a few
degrees one way or another, he could discriminate against nearby instruments, and by moving it into a
proper location for that particular instrument or group of instruments he could lay down the sound he
wanted on its dedicated track. The side rejection changes when the mike is tilted just a small amount.
The response of the dish at the low end is excellent. For additional isolation, Mark suggested a
deeper version and these have been made and are being tested.
For those who have not seen one, the “dish” is a circle of 1/8 or 3/16 plexiglass 12" in diameter with a
1/2" flat flange around the edge. The center is raised up 3 inches. The 2LV [now the GLM-100] bar is
mounted inside the dish so the boundary curves away from it and tightens up the pickup pattern. A
stand mount is fastened to the dish so that it can be mounted on a stand or a boom. A short gooseneck provides for flexibility for setting angle and direction. (A photographic toggle is being used to
provide flexibility on some newer versions.)
The PZM-2.5-12" is made with a 12" x 24" section of plexiglass heated and bent in the center to form
a 135 degree angle. This is fastened to a plexiglass base. The bar is removed from a 6S and fastened
to the plexiglass base. This provides 10 dB of gain in the forward direction and up to 40 dB of rejection off the back.
The PZM-2.5-8" is just like the 2.5-12" but is made with an 8" x 16" boundary.
Editor’s Reaction
I was very pleasantly surprised when Vince Motel and I visited the Utility Muffin Research Kitchen and
explored PZMicrophony with Frank Zappa and his recording engineer Mark Pinske. Frank had purchased PZMs (Crown 3OGP) quite early in their history and enjoyed using them in many ways. He
had made a video tape in his studio with a plate fastened to his forehead with an elastic band as he
interviewed people.
After checking several new prototypes Vince had taken, Frank and Mark wanted to really explore uses
of PZMs. For two hours they put us on the hot-seat seeking information that would help them use
PZMs for miking the symphony orchestra in London. If a question required a “Sorry, it won’t work that
way” answer, there was always a “Well then, what if” question that built upon that information to seek
a solution to the anticipated need. Such an exploratory stance is extremely important in developing
skill in using PZMs.
That interest and enthusiasm has continued since the recording and editing of that tape. New uses
are being developed in re-editing former masters or other music Frank has in his vault.
We need to recognize that this recording has been in the composing and planning stages for years,
and Crown appreciates Frank’s willingness to test our technology. It is such a good recording. We pay
tribute to his courage as he learned to use PZMs in so many ways.
I have been privileged to listen to the tapes in his studio, and the realism and presence of the instruments are something I have not heard in other studios unless they also use PZMs. There is an additional factor in this music also. The separation that Mark obtained with close miking places you in a
listening position right behind the conductor. The demonstration records sound, on a good system with
“time aligned” speakers, as though you had the instruments in your listening room. If you have not
heard PZMs like this, get this recording and listen. It is produced by Barking Pumpkin Records. Find it
in your favorite record store or tell them to order it.
There is an interesting article on this record in the December issue of the RECORDING ENGINEER
PRODUCER magazine. It is an interview by Vince Motel. Look for it.
NEW PROTOTYPES BEING TESTED
After the recording sessions in London, Mark Pinske, Frank Zappa’s recording engineer, suggested
that a deeper dish would provide better isolation and tighter focusing for closer pickup of the instruments. The dishes were made 3" deep rather than 2", and he has found that they accomplish what he
sought. He is using two of them tilted down away from each other over the drum kit, as they redo
tracks on some of Zappa’s other recordings.
A 7260 version of the 1560 was made and tested as a stereo mike with a boundary installed inside the
60 degree fold at the center and a bar placed on each side. This was tested as a stereo marimba
pickup. It worked well but needed a larger boundary. It is being used as a stereo ambient mike in the
live portion of The Utility Muffin Research Kitchen, Frank’s recording studio. A larger two-piece version with 24" x 36" folded plexiglass and a boundary installed on one end is being tested. These are
equipped to mount on stands at whatever height the engineer desires. These are being used for
vocals with ambience as well.
A 4060 version of the 1560 has been tested for the lectern of a Christian Science Church. A single
microphone can reinforce both readers. If one of the readers has a considerably different volume level
than the other, the bar and capsule can be mounted off-center to compensate for the difference.
Pierre Michelov, the sound engineer for the Long Beach Municipal Band, has ordered some 2.5-18"
units to use behind his French horns. These are also being tested with the San Diego Symphony and
will be evaluated in the next issue.
Some folding 48" pyramids are under construction using the special plastic material “TUFFAK
TWINWALL” for lightness. A theater organ concert will be used to test them in November and reports
will follow.
ARTICLE TO READ
Find a copy of August RECORDING ENGINEER PRODUCER and read the article “Realistic Stereo
Miking for Classical Recordings,” by Michael Lamm and John Lehman.
SOUND GRABBER: THE FIRST CONSUMER PZM
Sound Grabber
The Sound Grabber, the first consumer version of the professional PZM, has now been introduced to
offer home and business recordists the opportunity for vast improvement in the quality of their recordings. Introduced at the Summer Consumer Electronics Show, the Sound Grabber is designed for use
with video and audio cassette recorders, and is equipped with a ten-foot cord with a 1/8" mike plug.
The new microphone provides an isolated output signal that will record easily on standard cassette
recorders and will effectively eliminate motor noise, muffled sounds and reduce room reverberations
that are often a problem with built-in mikes. Because the Sound Grabber promotes high quality sound
with a clarity not before available, and is capable of establishing room ambience, video taping with the
new microphone reflects the feeling of actually “being there.”
Crown suggests using the new microphone for recording one-to-one interviews, group discussions,
conferences, family gatherings, amateur vocal and instrumental performances, and speeches. “In
operation, users will actually experience an improvement in the performance of their regular recording
equipment,” Clay Barclay, product development manager, commented. The Sound Grabber is especially suited for home use, since its rugged construction will survive many years of rough handling.
PZM 180: A MID-PRICED MUSIC PZM
Also available to the advanced amateur or beginning professional is the PZM 180 [now the PZM-185].
The PZM 180 microphone offers a wider dynamic range than the Sound Grabber, making it more
suitable as a music mike. Conferences, interviews, group discussions, home video productions,
broadcast news and sports are other possible applications.
The PZM-180 is a balanced output model that has a self-contained “N cell” power source, as well as
internal electronics for phantpm powering adaptation. The microphone’s frequency response is extended and smooth, and the hemispherical polar pattern allows wide pickup.
PROFESSIONAL MODEL 12SP
Crown’s new 12SP [now the PZM-30D] model offers studio quality in recording, sound reinforcement,
broadcasting and electronic news gathering for the experienced professional.
The 12SP is designed for phantom powering by a supply providing 12 to 48 volts. It features a transformer balanced, low-impedance output and an integral XLR connector; wide, smooth frequency
response with high-frequency emphasis for brilliance; low noise and high output level; a hemispherical
pickup pattern; high sensitivity and excellent reach for clear pickup of distant sounds.
In operation, the ruggedly constructed 12SP can be placed on a surface such as a floor, table, or
lectern; used as a hand-held microphone; or affixed to a surface near a sound source such as the
underside of a raised grand piano lid.
MODEL 2.5: CROWN’S HIGHLY DIRECTIONAL PZM
The PZM-2.5 [replaced by the PCC-160] is designed to improve directional pickup. The new lowprofile, minimum visibility microphone combines a precision-calibrated pressure capsule with a nearly
invisible corner boundary to achieve improved directionality of coverage. It effectively captures and
emphasizes sounds approaching from its front while rejecting sounds from behind.
The PZM-2.5 is recommended for applications such as theater productions, conferences and public
speaking. The microphone effectively eliminates audience noise pickup while providing excellent
coverage for the user.
In operation, the microphone can be placed on a surface such as a floor, table or lectern and aimed at
the desired sound source. The corner boundary design increases the microphone’s sensitivity and
actually improves speech articulation through its specially tailored frequency response.
And, the PZM-2.5 is convenient to use. The microphone plugs directly into a 12 to 48 volt phantom
power supply, includes a transformer-balanced, low-impedance output and a permanently attached
15-foot cable. These microphones all feature a black base; the B4C has a 4" clear boundary, the B8C
has an 8" clear boundary, and the B4D has a 4" dark boundary.
BOUNDARY EFFECTS
I’ve been using PZMs for a variety of reinforcement applications in client churches over the past two
or three years. Recent experiments - and experience - have prompted a couple of questions/ observations:
1. How critical is the distance from the capsule to the nearest boundary (e.g., on a 2.5 or pyramid)?
Put another way: how much leeway is there in placing the capsule; at what point do you lose the
benefit of the additional surfaces; can you get the capsule too close?
2. I’ve noticed what appears to be a buildup or increase in midrange response on 2s and 2.5s. Has
anyone else reported something similar?
3. Recently I encountered a bit of distortion - seemed to be upper mid-range - when using a 2 with 65
degrees between the two surfaces. Any ideas?
Thanks a lot - keep up the good work with the PZMemo.
Warren Ediger, Omaha, NE
Reply:
1. Regarding the effects of capsule spacing from nearby boundaries: I’m assuming the microphone
capsule is mounted a fixed distance (about .020 to .050 inch) from the honzontal boundary, due to the
built-in gap in the capsule holder. This spacing between the capsule and the boundary it faces should
be maintained for flattest high-frequency response.
Now suppose you add a vertical boundary, such as in the 2.5. The capsule should be placed as close
as possible to the vertical boundary for flattest high-frequency response. That is, the “nose” of the
capsule holder should touch the vertical boundary.
Correct PZM placement near boundaries.
As the capsule is moved away from the vertical boundary, sharp dips in the high-frequency response
occur. These are due to phase cancellations between the direct sound reaching the capsule and the
reflected sound off the vertical boundary.
Incorrect PZM placement near boundaries.
To demonstrate this effect, talk into a PZM 2.5 while varying the horizontal spacing between the capsule and the vertical boundary. Repeat a phrase with a lot of high-frequency content, such as “Sally’s
sister is a thespian.” You’ll hear the high frequencies diminish first as the capsule is pulled away from
the vertical boundary. With enough spacing (say, 3 inches), the phase cancellations will extend into
the mid-frequencies, reducing the microphone’s sensitivity at those frequencies.
If for some reason you can’t mount the capsule holder so that it touches the vertical boundaries, do
the following: Make recordings of the microphone’s output for various capsule spacings. See how far
you can move the capsule away from the boundary before the sound quality becomes unacceptable
for your particular application.
The lowest frequency that cancels is f = C/4S, where C = the speed ofsound (13560 i.p.s.) and S =
the capsule-to-boundary spacing in inches. For example, a 1/2-inch spacing should cause a cancella-
tion at 6780 Hz, noticeably reducing the clarity of “S” sounds.
2. There is an apparent mid-range boost with the 2 and the 2.5 boundaries. That’s because the vertical boundaries are too small to reinforce the low frequencies, but they do reinforce the mid-to-high
frequencies.
The low-frequency response shelves down about 6 dB at a frequency f = C/6D, where C = the speed
of sound and D = the boundary dimension.
In addition, the vertical boundaries reinforce frequencies whose wavelength is approximately the same
as the boundary dimensions (a phenomenon called diffraction). For example, a one-foot-square vertical boundary best reinforces frequencies having a one-foot wavelength (about 1 kHz). The frequency
of major reinforcement is f = .88 C/D, where C = the speed of sound and D = the boundary dimension.
In the Crown PZM-2.5, the vertical boundaries are carefully sized to aid clarity and articulation by
gently boosting the upper-mid frequencies.
3. Mounting a PZM between two boundaries angled 65 degrees apart should not cause harmonic
distortion. The THD of the microphone is 1% for 148 dB SPL at the mic capsule. If two boundaries
each boost the SPL at the microphone 6 dB, that puts the l percent distortion point at 148-12 or 136
dB SPL, which is still greater than the output of most sound sources.
Perhaps the boundaries’ mid-range boost is overloading your mixer or recorder input. Try a pad or
resistive attenuator.
Bruce Bartlett, Microphone Design Engineer
PZM VIBRATION PICKUP
Can I use 2 PZM-2ORMG [now the PZM-20R] in a stereo radio station on the desk table without any
noise problem from people hitting the table?
Denis Aubin, D.A. Productions & Consulting, Sherbrooke, Quebec Canada
Reply:
Although the PZM is insensitive to mechanical vibrations (such as table thumps), it still can pick up the
sound of desk knocks acoustically, like any other microphone. You may want to pad parts of the desk
to avoid generating sounds from people hitting the table.
If possible, borrow some PZM’s (3OGP, 31S, 6LP or 6S) and lay them on the desk top to test for
thump pickup. If the noise is acceptably low with these PZMs, it also will be okay with the built-in PZM2ORMGs.
Bruce Bartlett, Microphone Design Engineer
PZM NOISE
We have two PZM3OGPB microphones with PA-18 transformer-less power supplies. We have had
these mikes about two years and I am quite pleased with their sound except for one thing. They seem
to have very low output and when I get sufficient gain from them, the noise is objectionable. In fact, it
is bad enough that I have practically quit using them at all over the last few months. My favorite application for them is acoustic guitar, but it sounds like he is playing next to a waterfall.
Here are the details. I used them with phantom power. I have tried a battery but that doesn’t seem to
make any difference. They are feeding our MCI JH-428B console, via Neumann microphone cables.
By the way, the phantom power supply is a Neumann 48v supply. In order to get the gain up to an
appropriate level, I have to run the mike preamp gain control on the console at wide open. By way of
comparison, a Neumann U-87 with the same source would only need to have the mike gain control
about 1/2 to 3/4 open to achieve the same level and at the same time the noise level would be considerably lower. I borrowed one of the new tubular transformer-type supplies from a friend to see if that
would help. The gain problem persisted, and the noise problem was only marginally better.
I like the sound of the mikes. However, the noise is apparent even in final mixdowns, so I have had to
stop using them for everything that I was using them for before.
Do you have any suggestions?
David M. Boothe, Rainbow Sound, Inc., Dallas, TX
Reply:
The open-circuit sensitivity of a PZM on a large surface is -70.0 dB re 1 V per microbar. For comparison, the sensitivity of a typical dynamic microphone is -75.0 dB (5 dB less sensitive). The sensitivity of
a Neumann U-87 is -65.0 dB. So the PZM is 5 dB less sensitive than the U-87, and that’s why you
have to crank up the fader for the PZM. The same would happen with any microphone of the PZM’s
sensitivity. [The sensitivity of current PZM models is -65 dBV/microbar.]
One solution is to increase the sound pressure level at the microphone, if possible. To do this, (1)
mount the PZM on a large surface, such as a wall, or (2) mount the PZM cartridge holder in the corner
between two or three boundaries (walls and floor), or (3) put the sound source closer to the microphone.
Another solution is to modify the PA-l 8 electronics. Locate R8 and R9, the two matched 619 ohm, lt’o
resistors between the two transistors. The smaller these resistors are, the greater the gain. For 8 dB
more gain, change them to 100 ohms. [or use a current PZM.]
If you suspect your mikes are defective, send them to Crown’s service department.
Bruce Bartlett, Microphone Design Engineer
PZMs IN FILM SCORING
I was at Wally Heider recording when Mr. Wahrenbrock first demonstrated his PZM mic and from that
day on they were considered essential on every session we did. For the film scoring division we suspended 3 mic’s for left center right about 20' above the floor. The sessions were still set up with gobos
and close miking. The PZM’s provided the majority of the audio in the mix while the close mikes provided balance and desired coloration. The application of the PZM is only limited by your imagination.
James W. Hearn, Ryder Sound Services Inc., Hollywood, CA
PZMs ON DRUMS, LESLIE ORGAN SPEAKER, AND SOUND EFFECTS
We suspended two 4 x 5 PZM’s from the ceiling of our drum cage on monofilament line in an overhead stereo configuration approximately 3-1/2 ft. above the drum kit. Board EQ stays flat and a natural sound can be adjusted in the mix if necessary. The natural pan of tom tom rolls and cymbals is
aesthetically superb. The monofilament virtually eliminates vibration and stand noise as well as clears
the area for more freedom to the drummer.
The 2" x 2" Wahrenbrock PZM’s fit well inside the rotary horn section of Leslie cabinets and with an
auto-panner give brilliant and exciting results. Because of the high acceptable level of SPL, the PZM
is valued to us for use in recording clear special effects (live reverb amp explosion, gunshots, etc.)
with clarity and no excess coloration.
Alan R. Cahen, Infinity Recording Studios, Tulsa, OK
PZMs ON ORCHESTRA
Greetings from western Australia! We have just started using your PZM’s on our orchestra (West
Australian Symphony Orchestra) and are extremely impressed with their performance. I would appreciate any microphone lay-outs you have for orchestral work. Also like to be put on your PZMemo list.
Keep yourselves nice.
Karl Akers, Australian Broadcasting Commission, Perth, W. Australia
PZM STAGE MIKING
For a recent high school production of Li’l Abner we supplied four PZM’s for sound reinforcement.
Three 2.5’s were spread across the front of the stage and a PZM pyramid was hung on a light bar
above a six foot high platform toward the rear of the stage.
It wasn’t until opening night that we found out that the mayor of Dogpatch was going to stand on that
platform, raise his hand, and fire a starter’s pistol to start the Sadie Hawkin’s Day race. His hand was
directly under the pyramid, about four feet below it. After three performances (and gun shots) the PZM
is still perforning!
Michael E. Lamm, Dove & Note Recording Co., Houston, TX
RECORDING ORCHESTRAS WITH PZMs
As the final semester of my Music Engineering Technology degree from the University of Miami, Fla., I
was fortunate to get a unique opportunity to work here in Norway with Norsk Rikskringkasting (NRK).
For the last four months I have been learning the ropes of European Broadcasting and music recording for radio and TV.
One of the main projects that I have worked on has been the recording of the Bergen Symphony
Orchestra in the great-sounding Grieg Hall. The hall’s layout and the NRK’s facilities allow for a lot of
experimentation with miking techniques so when I read about the PZM challenge in a trade magazine I
thought that trying some PZMs in the hall might be worthwhile. My supervisor, Tore Skille, was also
interested in experimenting with PZMs.
At that time, our section didn’t have any PZMs so we borrowed 2 or 3 from the Grieg Hall’s audio
department. We tried them on the ceiling, on the floor, on the walls, EVERYWHERE. Each positioning
gave us a different perspective, but we finally settled on flying the mikes, back to back, on a circular
10-1/2" metal plate above the conductor’s head. Our remote controlled flying rig allows a broad range
of mike placements to compensate for group size and musical selection, but usually we end up positioning the mikes 1-2 meters above the conductor.
The clarity and definition the PZMs give is fantastic. We use conventional Schoeps (omni) for side fills
and ambiance, but the pair of PZMs provide the main signal. By using the PZMs and omni mikes we
minimize phasing problems and have virtually no off axis coloration. This makes things a lot easier
because most of our recordings are made for radio broadcast.
Our department now has its own pair of PZMs and they have already earned their position in the
Grieg Hall. My stay here is almost over, but I think the PZMs stay has just begun. Thanks for being
included in this special opportunity in audio education.
Mark Drews, Milford, MI
ATTACHING PLATE TO MIC STAND
We’ve found a great way to attach a plexi boundary plate to a mic-stand! Drill and tap holes in an
Atlas SW-1 for flathead machine screws and countersink them into plexi! Mount PZM with Velcro.
Steven Hirsch, The Mixingboard, Burlington, VT
ENVIRONMENTAL SOUNDS
I was absolutely amazed to read that no environmental sounds were entered in the PZM contest. I
have made some incredibly striking recordings in this area - pigs grunting at feeding time -the interior
of a chicken coop - and most amazing, the sound of traffic beneath the Brooklyn Bridge, which resembles a massive hive of monster bees! They were all made with a stereo pair of PZMs on a Nagra
IV-S at 15 ips.
I meant to enter the contest, but just never got around to it. It’s a pity, because I have now read the
rules in detail, and see that the prizes were really worth competing for.
Also, I really expected you would get many responses in the environmental category. I suppose it
would not be fair or feasible to extend the contest in this category. I do hope, however, that you will
run the contest again in a year or two, and that you will not delete the environmental category. I promise I will enter!
Reynold Weidenaar, New York, NY
Reynold - Rest assured there will be a PZM Challenge in 1984. As a recipient of PZMemo, you’ll be
notified. Editor.
PZM TURNS UPRIGHT PIANO INTO A GRAND
I have a new recording studio with an upright piano. I was worried about getting the right sound with
an upright. The PZM calmed my worries. I had people ask if I had a grand piano. The PZM gets rid of
that mid-range “mud” and boosts the high and low end for an incredible sound. The PZM saved me a
$10,000.00 investment in a grand piano.
Tim Greene, Mountain Top Recording, Boone, NC
###
PZM MEMO
February, 1984
Bruce Bartlett, Senior Editor
Ken Wahrenbrock, Contributing Editor
ANNOUNCING THE 1984 PZM CHALLENGE
Have you made a PZM recording that’s especially impressive? Do you plan to make one soon? If so,
enter it in the PZM Challenge 1984, the yearly contest to determine the best original stereo recording
using PZMs as the main microphones.
The Challenge is divided into an “open” contest, which can be entered by anyone except Crown
employees and their families; and a “dealer” contest, open only to Crown dealers and their employees.
Three categories are established in each contest: classical, popular, and environmental. Category
winners receive their choice ofa pair of PZMicrophones. Grand prize winners also receive a Crown
home audio system consisting of an FM-2 Tuner, an SL-2 Preamplifier and a PL-2 Power Amplifier, all
in a walnut cabinet. Honorable mentions- entries of more-than-average interest - receive a fifty-dollar
certificate applicable towards the purchase of a PZMicrophone.
Forty people entered the contest in 1983, so you have a good chance of winning. To increase your
chances, we recommend the following:
I. Use high-quality recording equipment. Noise, distortion, and compression should be inaudible.
2. Record in a venue with good acoustics.
3. Record exciting music that demonstrates the full frequency range of the PZM.
4. Use PZMs in unusual ways, and carefully describe your miking setup. Otherwise the judges just
assign an average score for creativity.
We’re looking forward to receiving some excellent recordings. Good luck!
NEW PZM LITERATURE
Since the inception of the Pressure Zone Microphone, we’ve all learned a lot about PZM acoustics.
This knowledge is available in a new booklet from Crown called the “PZM Theory and Application
Guide.” Based on Ken Wahrenbrock’s application notes, the new guide is the clearest explanation yet
of PZM operating principles and techniques. [The current version is called The Crown Boundary
Microphone Application Guide.]
The contents cover such topics as Pressure Zone theory, controlling the PZM’s low-frequency response, shaping the polar pattern, microphone techniques, and phantom powering.
The PZM Theory and Application Guide is available free for the asking from Crown, and is included
with each new PZM.
Articles on the PZM appeared in the January issues of Modern Recording & Music and Tape Deck
magazine. The December issue of Recording Engineer/Producer featured a rebuttal to Stephen
Temmer’s criticism of PZMs.
TWO-TIME PZM CHALLENGE WINNER
Alfred Grunwell, right, has won the PZM Challenge two years running.
Winning the PZM Challenge is a real achievement in itself, but Alfred Grunwell won the contest two
years in a row! He’s the co-owner of Calf Audio, a recording studio in Ithica, New York.
Alfred said that the award “is gratifying to us because it means that Crown doesn’t simply look at the
return address and toss everything that’s not from California or New York City. And the award shows
that experience and the way it sounds actually still do count for something, which is pleasant to hear.”
Alfred uses PZMs extensively because he says they sound “bright, crisp, and articulate,” compared to
many traditional microphones which sound “smeared and blurry” when they pick up sound reflections
from nearby surfaces.
In his recordings, he uses both conventional microphones and PZMs. They complement each other,
each microphone reproducing sound more effectively in different applications.
For example, Alfred prefers conventional microphones for lead vocals, but finds PZMs usable on any
instrument. PZMs provide a strong attack on drums and are equally effective for recording piano,
acoustic guitar, and violin. “They sound exceptionally good on vocal choruses,” Grunwell adds, “because they give you a high degree of articulation and they have a great deal of reach, so people don’t
have to be right near the microphone.”
Alfred recently promoted the PZM in the October 12, 1983 issue of The Times Monitor, Central New
York’s College newspaper. Thanks for the mention, Alfred, and congratulations again.
CLEARING UP PZM MISCONCEPTIONS
Many people are confused about PZM operating principles. Here are some explanations of various
phenomena in PZM acoustics to help the sound engineer use PZMs more effectively.
I. The PZM does not eliminate sound reflections from the surface it’s mounted on. It uses them. Sound
reflections add effectively in-phase with the direct sound from the source, over the audible range. This
increases the sound pressure at the mike capsule by 6dB, which boosts the sensitivity 6 dB and
increases the signal-to-noise ratio by 6 dB.
What the PZM eliminates is the audible effect of sound reflections. If a conventional microphone is
placed near a sound-reflecting surface, the reflection arrives at the mike after the direct sound. This
causes phase interference, comb filtering, a degraded frequency response. But with the PZM, the
reflection arrives at the mike diaphragm simultaneously with the direct sound, which allows a flatter
frequency response.
2. The PZM plate is not a transducer; it does not convert sound into electricity. Instead, it serves as a
predictable, hard surface to reflect sound into the mike capsule.
3. If you use a PZM on a large surface such as a wall, table, or floor, the frequency response is wide
and smooth. Ifyou use the PZM as is on a microphone stand, you lose bass and add upper-midrange,
due to the size of the plate. Many sound engineers like the effect and use it in their recordings.
If you mount the PZM on a large panel, the low-frequency response shelves down about 6 dB at and
below the frequency F = C/6D, where C = the speed of sound and D = the panel dimension. This lowfrequency shelf does not occur at grazing incidence (sound-wave motion parallel to the panel). As you
closely approach the panel (less than a panel dimension away), the full bass response returns.
PZM IN BILLBOARD SURVEY
Billboard Magazine annually surveys recording studios around the country to determine how many
microphones of each brand are used. PZMs were on the list for the first time this year. They were
used by 37.7 percent of the studios surveyed. Not bad for a microphone manufactured by Crown for
only three years! That is rapid acceptance for such a new product. The first Wahrenbrock prototypes
were available in September 1978.
CROWN ANNOUNCES A STAND-MOUNTED BOUNDARY FOR PZMs
A PZM, having a hemisperical polar pattern, is sensitive to every sound around it. As a result, in some
applications it may pick up too much unwanted sound; such as audience noise, muddy room acoustics, or squealing feedback. Crown has introduced a new “boundary” or panel that solves these problems by making the PZM directional: sensitive to sound from one direction.
The Crown A240 Boundary [discontinued] is a transparent plexiglass panel, two feet square by 1/4"
thick, to which a stand-mounted PZM can be attached. The boundary extends the low-frequency
response, increases gain-before-feedback, and reduces pickup of leakage, audience noise, and room
acoustics.
If you mount a PZM on a microphone stand, it may sound thin in the bass because the plate provided
with the microphone is too small to reinforce low frequencies. But by mounting the PZM on the A240
Boundary, the low-frequency response is greatly extended, providing a fuller bass sound.
The boundary also makes the microphone sensitive to sounds approaching from the front of the
panel, while rejecting sounds from the rear. That is, it makes the PZM directional — helping it reject
audience noises, room acoustics, and leakage (off-mike sounds from other instruments). And, thanks
to the boundary, the PZM can be turned up louder in sound-reinforcement systems before feedback
oecurs.
The A240 includes a sturdy, adjustable stand adapter to mount the panel to any standard microphone
stand. Holes in the panel let you suspend or “fly” the microphone panel on nylon lines. Two microphone mounting clips are attached to opposite sides of the panel for stereo recording.
LETTERS ABOUT PZM APPLICATIONS
PZM for ambience
Dann F. Haworth, an engineer at Chapman Recording Studios in Kansas City, sent us the following
diagram of his PZM application.
A PZM is mounted on the center of the glass-walled vocal isolation booth. It picks up room ambience
for electric-guitar tracks. The PZM’s signal is mixed with that of a close-up B&K microphone.
PZM placement in studio.
Recording small groups with PZMs
I found a way to accurately record less than four sources. I placed two PZM-6LP [now the PZM-6D] on
a concrete wall, 10 feet apart and 4 feet up. The room should be as dead as possible. I used an AKAI
GX-747 with Dolby A or C.
The recording was played back through a Perreaux PMF 2150B power amp through KEF or ADS
L2030 speakers, with the tweeter and midrange positions matching those of the original mikes.
The tape was proeessed through Carver’s Sonic Holograph circuit with the original channels reversed,
Derek Richardson, DBS Recordist, Chicago, Bollingbrook, Illinois
Miking guitar and audience with PZMs
On August 13, 1983, I was involved in a recording session featuring Tommy Tedesco, a guitarist.
Tommy has been involved in the studio scene so long that he is known to other guitarists as “The
Godfather.” The session was for a sampler disc for CBS records. It was digitallv recorded.
The recording was done at HOP SINGH’s in Marina Del Rav California. PZM 3-12" were used around
the club to pick up the room sound.
Tommy and Jimmy Bruno both played nylon-string acoustic guitars. The only other instrument miked
was a mandolin, which Jimmy used on two numbers. To record these instruments, we used two
protoype PZM Dishes. They were 12" in diameter and had a 3-1/2" rise in the middle, with the microphone capsule/holder mounted a! the center inside. The dishes were placed about 6" in front of the
guitars’ sound holes.
Tommy Tedesco’s session.
Keep in mind that Tommy has been recorded virtually every day for the past twenty years. He has
played the themes from M*A*S*H and Bonanza, worked on the “50 Guitars” albums from the early
60’s, and worked for acts like the Beach Boys and Frank Zappa. He has worked on so many
comercials and theme songs for shows, that you have undoubtedly heard his artistry.
Take this into account when you read the following: After listening to the playback, Tommy said “This
is the best recording I have ever heard of my guitar. It sounds just like I hear it live.”
Since that recording date, I have received a call from him wanting to know more about PZMs. Since
he is planning some future products, you will probably be hearing more of Tommy Tedesco recorded
with PZMs. We’ll keep you posted.
Vince Motel, Audio Stuff, Downey, CA
Orchestra pickup with PZMs
We provided sound reinforcement for the Tallahassee Symphony Orchestra for the last three of their
performances last year, all held in the Tallahassee Civic Center. We were contracted to provide sound
reinforcement because the house sound system was designed for voice, and was not full-range in
frequency nor set up to pick up the music.
We wouldn’t have been able to do as well as we did without Crown equipment and advice. The overall
arrangement was suggested by David Johnson, Studio West Recording Studio, The PZM Memo, and
Ken Wahrenbrock.
Crown PZM Microphones were used to pick up the overall orchestra sound. We used two Crown-PZM
3OGP and three PZM-6LP on 2' X 2' sheets of plexiglass (to extend the low-frequency response)
suspended overhead [now the PZM-30D and PZM-6D]. But we probably should have used 4' X 4'
sheets instead.
Additional pickup was provided to the bass section and special areas such as solo-guitar artists and
piano solos.
We used a Tapco 7416 mixer to mix the house sound and to feed audio to the television crew. The
show was aired on WFSU Channel II (Public Television Station) and WFSU FM 91.5 (Public Radio
station).
The house sound system was engineered to provide frequency response from 20 Hz to 40 kHz. All
this was made possible by using Crown EQ-2, SA-2 (2), MX4 (2), DC-300A1 1(6), D150-AII (2), PL-2
(2), D-75 (2), and numerous other components.
We used a Technics SV-PI00 Digital Audio Cassette Recorder to record the final concert, and submitted a copy of this tape to Crown for the PZM Challenge (and won).
We enjoyed this project and learned a lot from doing it.
Willie T. Menasco, Stereo Sales, Tallahassee, FL
Miking a Leslie cabinet with PZMs
I’ve used PZMs for kick drums since first reading about them. I have just used a PZM for a new experiment, and am delighted with the results.
The keyboard player I work with uses a Leslie 147 cabinet with a JBL 2220 B for low end. I was using
a Shure 5M57 microphone with a windscreen, but the larger the room, the more volume needed hence, the more rumble.
With a minor modiflcation of the cabinet, a PZM was mounted by drilling four small holes in the plate,
and attaching the plate to the lower left inside wall of the cabinet. The results were great.
Mark Perrin, Fat Sound, Rensselaer, NY
Recording a jazz trio with PZMs
On August 9th, 1983, we recorded the Shelly Manne Trio at HOP SINGH’s in Marina Del Ray, California. The Trio consisted of Sheily Manne on drums, Frank Collette on piano, and Monty Budwig on
acoustic bass. This was for a sampler disc for CBS records to be released on compact disc. PZMs
were the only mikes used. The date was recorded in Sensurround with PZMs as the room mikes
.We used three PZMs to record the drums. Two were dishes for overhead. These dishes were 12" in
diameter and had a 3-1/2" rise in the middle. The kick-drum mike was a 2.5 model with a 12" back
plate. The separation in this setup was remarkable. We got no piano or bass on the drum tracks.
Shelly Manne remarked that that bass-drum sound was the best he ever heard. He also thanked us
for capturing all the subtleties and nuances of his playing (he generally plays quietly, using brushes a
lot).
The piano was miked with a PZM mounted on a 2' X 2' plate aimed at the high end, and a 1560
boundary accessory over the bass strings. At times, Frank plays the piano by reaching inside and
plucking the strings. This is a very quiet sound, and texturally is like a guitar. The PZMs picked this up
very well.
The bass was miked with a PZM-2.5 model taken to extremes. The back plate was 18" tall and 3 1/2
feet wide. This captured an incredible low end.
The room mikes were PZMs mounted in 90-degree plastic corners. Two were at the edge of the
stage, with the off-axis side pointing towards the audience and the group (see illustration). The rear
room mikes were in the same configuration but about 18 feet in the air.
We converted a lounge in the club into a control booth with Sonex acoustical foam. The ambient
mikes were encoded into a quad spread with the CBS Labs Encoder.
Vince Motel, Audio Stuff, Downey, CA
Shelly Manne Trio recording session
Recording fireworks with PZMs
On July 4th, I got a great sound recording fireworks with PZMs taped to the glass window panes of my
house - three miles from the fireworks site.
I also recorded another fireworks display (as an assignment) on-site with a van. One PZM was taped
to the windshield. The windshield wiper was inadvertantly turned on, and ran over the mike 15 times
before being shut off (didn’t damage the mike). Another mike was on top of the van. I got a wonderful
sound to use as an effect on a record called “Bomb Boys” being worked on in my studio.
I also use my kitchen as an echo chamber. Bright-sounding echoes are picked up with two PZMs
back-to-back on plexiglass.
Alfred B. Grunwell, Calf Audio Inc., Ithica, NY
PZMs in studio, theater
My first experience with PZMs was as an audio technician at a radio station in Southern California in
1980. The piano in the studio did not appear to be miked, yet the reproduced piano sounded like the
instrument was in the control room with us! Only later did I figure out that the gentleman so solicitous
of the piano sound was Ken Wahrenbrock.
Since then I’ve used PZMs in recording (perfect ambience mike, not my favorite for drums); live (great
for piano and brass if the pattern can be shaped so as not to pick up other sounds); and theater (four
mikes placed all-the-way downstage, on plexiglass, aiming away from the audience - this approaches
miraculous performance for monitoring and foldback purposes).
Farrell Winter Sueslosky, Independent Productions, Long Beach, CA
TWO NEW PZMICROPHONES FROM CROWN
PZM-2.5 [since replaced by the PCC160]
PZM-2.5
This is Crown’s first directional PZM, highly recommended for stage-floor pickup of drama, musicals,
and opera. The mike capsule is mounted in the corner of three reflective surfaces that shape the polar
pattern. Stage dialog is emphasized while audience noise and orchestra sounds are rejected. The 2.5
provides 10dB of forward gain for outstanding “reach.” It greatly reduces pickup of room acoustics and
feedback. Self-noise is virtually inaudible.
Electronics in the base adapt the unit for phantom powering. The output is balanced, low impedance.
The clear plexiglass boundaries are nearly invisible from a distance, and are carefully sized to enhance speech articulation.
PZM-12SP [now the PZM-30D]
PZM-12SP
The PZM-12SP has a bright, crisp sound like the PZM-30GP, but is designed for somewhat different
applications. Since it weighs very little, the 12SP can be safely attached to ceilings or suspended
panels. And it includes a handle for easy stand mounting - say, over drums.
The housing and plate are made of conductive carbon-filled nylon, which provides better RF shielding
than other lightweight alternatives. Being non-resonant, this material doesn’t “ring” when subjected to
shock. The integral handle permits the microphone to be hand-held, stand-mounted, or simply laid on
any hard surface. Built-in electronics adapt the unit for phantom powering.
###
PZM MEMO
July, 1984
Bruce Bartlett, Senior Editor
Ken Wahrenbrock, Contributing Editor
CROWN PZMs USED IN NASA SPACE SHUTTLE!
PZMs used in space shuttle flight.
Crown PZMs are not only used around the world; they have orbited around the world. During the April
6, 1984 flight of the NASA space shuttle (Flight 11), PZMs provided the sound track for a 70-mm film
showing life aboard the space craft.
The project was sponsored by Imax Corporation, a Canadian film company. Their film will be shown
next summer on an enormous screen for tourists at Cape Canaveral, and at the National Aeronautics
& Space Museum at the Smithsonian Institution.A PZM is an ideal microphone for this application
because the space shuttle has so many reflecting surfaces. The Crown PZMs were appreciated for
their small size, light weight, and clear, natural audio.
The microphones were PZM-6S models [now the PZM-6D], modified by Crown microphone engineering to meet the rigors of space flight. We designed a new battery power supply that weighed less than
the standard PX18 interface, and selected two mic capsules with a sufficient “barometric leak” to
withstand sudden changes in air pressure.
The mics were carefully assembled with special Teflon-insulated mic cable supplied by NASA. The
assembly was potted in place to prevent damage from vibration.
We acoustically “tuned” the two units for the desired frequency response and to match the two mics in
tone quality. The chosen response was midway between that of the 6S (flat) and 6LP (presence
peak), providing an articulate yet natural sound.During the space flight, the microphone plates were
attached with Velcro to the walls of the shuttle to prevent the mics from floating away. The PZMs
plugged into a Sony cassette recorder to record speech aboard the space craft. According to Imax,
they worked fine.
Shuttle flights 14 and 17 will also include PZMs for more sound track recordings. We’re proud that
Crown was selected to help document these historical missions.
PZMs PROVIDE REFERENCE-QUALITY SIGNALS
PZMs are being used to generate clean signals for critical listening tests. The Swiss section of the
Audio Engineering Society met last summer to examine digital recording. PZMicrophones were used
to pick up an orchestra playing in another part of the building, and the signal was brought to a mixing
console which fed a digital Studer A808 prototype PCM transport. Program material was monitored
both before and after tape to determine the audible effects of digital recording.
It’s gratifying that the Swiss section judged the PZMs to be clean enough to provide a reliable signal
source - one that does not mask small differences farther down the audio chain.
STEREO-TV TECHNIQUE
Here’s a stereo-TV application for PZMs. Gary Pillon, of General Television Network of Michigan,
suggests the following boundary system: On top of a portable TV camera, mount a “V” or wedge
made of two pieces of plexiglass one-foot square. Screw a PZM-6LP [PZM-6D] to each panel, aiming
left-front and right-front for stereo pickup.Place the panels in front of the camera, as far as possible,
so that acoustic noise from the camera is rejected.
To cut wind noise in outdoor shots, mount some stretched nylon stockings or open-cell foam over the
microphones. Best wind rejection occurs when the screening is spaced far from the microphones.
Gary also has a tip for PZM users who want to raise heavy PZM boundaries on mike stands. Try a
“Mole High-Riser,” a lighting support used to hold 5000-watt lights 15 feet high. They are available at
many video rental houses.
CROWN PZM VS. RADIO SHACK PZM
Many of you are aware that Radio Shack is selling a low-cost PZM. Crown licensed the right to manufacture PZMs to Radio Shack.Although the Radio Shack model is good for its price, you get what you
pay for.
The Crown PZM most competitive in price with the Radio Shack model is the Crown Sound Grabber.
Here are some advantages of the Sound Grabber that justify its higher price:
*Self-contained. No in-line battery box.
*The battery lasts much longer, so no on-off switch is needed.
*Can be hand-held or stand-mounted as well as used on a surface.
*Lighter weight allows easier mounting on walls and ceilings.
*Unit-to-unit consistency is better, because the microphone capsules must fall within rigid performance
limits.
*Much more sensitive (15 dB).
*Made in U.S.A. by Crown, which also builds highly regarded studio microphones.
*If the user wants to upgrade to higher-quality PZMs, or needs a special-purpose PZM, Crown manufactures an entire line of PZMs for varied applications.
THE DEVELOPMENT OF THE MULTI-BOUNDARY PRESSURE ZONE
MICROPHONE
by Ken Wahrenbrock
EDITOR’S NOTE: This is a comprehensive history of the use of multiple boundaries with PZMs. In
general, the more boundaries that are used, and the bigger the boundaries, the more directional is the
pickup pattern. And the more directional the pickup pattern is, the less is the pickup of ambience,
leakage, and unwanted noise. We thank Ken Wahrenbrock for his pioneering work with multiple
boundaries, and for this interesting history. The models mentioned in this article are not commercially
available, but are easy to build.
In early 1979, during one of the Syn-Aud-Con seminars, Farrell Becker suggested using more than
one boundary for PZMs. So we taped three pieces of base-plate together with gaffer’s tape, and
loosely mounted a PZM cantilever and capsule in the corner (Figure 1).
Fig. 1: 1979 - The first experimental multiboundary PZM put together with gaffer’s tape. The increased gain
and directionality were immediately apparent. It was similar to a PZM-3.
Fig. 2: Early sample of a PZM-2. When a PZM-2 or PZM-3 is placed at the junction of two or three room
boundaries, recorded room ambience is dramatically reduced.
We monitored the microphone with headphones. The gain and directionally were greatly increased,
and the reduction in reverberation pickup was startling - even when the talkers were 30 feet or more
from the microphone.
Some of these early models were made from aluminum plates. The PZM-2, as it was called, had a
second plate wedged on to make an “L” (Figure 2). The height of the backplate was 5". Some PZM-3
microphones (Figure 1) were also made by adding a third boundary welded to one end. The cantilever
and capsule were mounted in the closed corner.
The early testing was done by placing the PZM-2 and PZM-3 at the junctions of walls. With the PZM2, the pickup pattern was reduced from a hemisphere to ‘A of a sphere. The PZM-3 further reduced
that pickup by half.
We found that positioning the microphone on one boundary eliminated the audible effect of reflections
or ambience from that boundary. Placing the PZM at the junction of an additional boundary further
reduced the reflections and ambience. Placing the PZM at the junction of three boundaries increased
the articulation and reduced the ambience still more, because one-half of the room reflections were
audibly eliminated.
These PZM-2s and PZM-3s were shortly tested by Brad Williams in the theatre workshop at Cerritos
College in Southern California. PZMs placed across the front of the stage added 6 dB of gain from the
second boundary. This greatly improved the pickup while reducing audience noise, compared to the
flat PZMs with carpet added for rear attenuation.
The stage pickup was excellent with the PZM-2, although the mic did not discriminate sufficiently
against the orchestra and the audience. The PZM-3, on the other hand, had too-narrow a pickup
pattern and left downstage areas uncovered.
PZM-2.5
Brad sought to solve that problem by splitting the difference - he built some PZM 2.5’s. The enclosed
angle was 135 degrees (Figure 3). These early models were made of dark plastic since aluminum was
expensive. The first prototypes were made in three pieces, with careful angle calculations on the table
saw. The height of the vertical boundaries was reduced to 4" to avoid blocking sighflines for the front
seats in the theater.
During 1980, the vertical-boundary sizes were increased. Constructing the boundaries of clear plastic
made them invisible. An 8" boundary gave a considerable improvement over a 4" boundary, increasing
the reach upstage and providing much better rear discrimination. It also lowered the frequency at
which the 6 dB shelving loss takes place.
These 8-inch tall 2.5’s have been used for solo mikes and group mikes when mounted on stands
because of their excellent reach and rear rejection. Several choral groups have used these for reinforcement pickup to balance the choral level with the orchestra level.
Later in 1980 we increased the boundaries to 12" and heard another order of improvement. TDS
measurements indicated 40 dB of discrimination in the midrange and above when the microphone is
placed on a large boundary like a stage floor. Many stages have used these to pick up musicals, with
the soloists standing 25 to 30 feet away from the microphones.
Many more 12" models are being used for high-school and college theaters, because youthful voices
have less strength and require more assistance. Where school auditoriums are not carefully engineered, PZMs have provided a margin which enabled the drama and music instructors to present their
classes in the best manner possible.
A larger version of the 2.5 - 18" high and over 36" long -is now being used in several ways. One of
these has been used by the San Diego Symphony for pickup of the French horns, and another for the
entire brass section. Again, the pickup with that size boundary is exceptional, and the discrimination
from the back is increased by an order of magnitude.
An additional version of the 2.5 is now being fabricated. The vertical boundary will be a 24" x 36"
piece of plastic, heated and folded to 135 degrees at the center of the short dimension. It will stand
36" high, and will be placed near the music stand for two string basses. This will provide much better
pickup of the total sound because the sounds from the F hole can be more clearly received.
Fig. 3: PZM-2.5 with an enclosed angle of 135 degrees.
Fig. 4: A PZM triangle pyramid. A model with 18" short sides was suspended overhead for stage pickup.
Another model with 4' short sides and 5-1/2' long sides was used to record an organ with reduced leakage.
Later versions of the 2.5 were made with the vertical boundary of one piece heated and bent in the
center. Mounting this on the base increased the strength. The latest version is made with additional
support on the base that allows the vertical boundary and the base to be screwed together. This
construction allows easier storage and shipping.
PZM pyramids
Back when the first 2.5 units were being tested, we also built some plastic boundaries shaped like
pyramids. The PZM capsule was mounted in the inner corner (Figure 4). The first ones were constructed 12" on the short sides of the triangles. Later models were increased to 18" and worked much
better.
Pyramids were suspended over stages in the borders for upstage pickup. Since the pickup pattern
was the extension of the planes of the three boundaries, the pyramid could be directed to cover particular areas. The assembly reduced offstage pickup and eliminated noise from overhead.
These pyramids delighted sound crews and directors. In several theaters, the designing architect was
more pleased with his acoustical and sound-system design when PZMs were used.The pyramids’
application in theater sound reinforcement was spreading. Several touring theater companies, when
introduced to PZMs, found their show engineers purchasing PZMs on their own when the show sound
companies would not make the purchase. The reinforcement was so much improved that the sound
engineer would not go back to traditional shotgun microphones.
Some narrower versions of the pyramid have been fabricated with an angle of 60 degrees rather than
the usual 90 degrees. This reduces the pickup angle. There is a bit of high-end comb filtering, but the
decreased pickup of room ambience and tighter pickup pattern provide greater reach.
Next we made two pyramids that were 48" on the short sides of the triangles, made with Tuffak
Twinwall. They were used for some theater organ recordings to reduce leakage from other instruments. They were suspended from the spotlight bridge in front of the divided organ chambers.
L-squared array
A very flexible version of multiple-boundary PZMs is the L-squared arrayby Mike Lamm (Figure 5).
Several articles have described his array and the variety of pickup patterns he has developed. The
recordings made with the L-squared are excellent and exciting.
Fig. 5: The L-squared array.
PZM Dish
A different type of boundary is a blown bubble boundary which we call the “dish.” The earliest versions
were a mere 6" in diameter with a depth of about 1". The cantilever/capsule was mounted on the
concave surface near the center (Figure 6). These dishes did not provide much more than the standard plates mounted on stands, so nothing more was done with them for a while.
Fig. 6: The PZM Dish, designed by Mike Lamm of Houston, Texas.
In 1981, I built ten dishes 12" in diameter and 2" deep. Dave Johnson used these with the San Diego
Symphony. He considered the results a great improvement over the traditional free-field microphones
he had been using.
Frank Zappa also used them in his classical recording. The engineers felt that they could be improved
by deepening them, so some were made 3.5" deep. These were startingly better, with a tightening of
the pickup pattern and better isolation from nearby instruments. They were used for solo instruments
in concertos, as well as instrumental sections for sound reinforcement of the orchestra.
Some of these were also produced with a diameter of 28". The reach is exceptional, but no practical
use has surfaced for these as yet. In foothall games they clearly pick up the quarterback calls, but
also reach across the field.
PZM Cones
A different form of dish termed the “cone” has been used. It is heat-formed of 1/8" plastic over a form
with an included 60-degree angle (Figure 7). It provides a much tighter pickup pattern than the dish. It
has been used as a “follow” microphone for a roving TV camera to provide an audio perspective
matching that of the video shot.
Fig. 7: PZM Cone. It has been used as a “follow” mike for a roving TV camera by Keith Warrn of Southern
California Edison. It provides the same audio perspective as the video shot.
1560-type boundaries
Crown is making an “L”-shaped boundary accessory called the 1560 [now discontinued]. It is 15" long
by 5" high, and has an enclosed angle of 60 degrees. Several 2260s and 2860s have been made to fit
particular pulpits and lecterns (Figure 8). One version has been built that is 40" long. A single PZM
mic mounted in it can pick up two persons using it at the same time. If one has a stronger voice than
the other, the bar can be offset to compensate.
Fig. 8: A PZM 2260 - 22" long with an acute angle of 60 degrees.
Several of these have been built even larger. One was made 72" long by 6" wide to pick up the marimba in stereo. A boundary was placed in the center and two bars installed as close to the center as
possible.
Two additional models have been tested with the boundaries made of plastic 24" x 36", heated and
folded to an internal angle of 60 degrees to make a microphone 36" long. End plates were installed for
directionality. Two of these have been used by Frank Zappa for stereo background vocals, ambience
pickup, and stereo marimba.
A special version of the 1560 was constructed for use in an auditorium where a teacher had to read at
a desk for long periods of time. Additional gain was required, since the reader wanted to lean back
away from the mike. Two side boundaries were added at 45 degrees on each side to provide additional side discrimination from the loudspeaker cluster (Figure 9).
Fig. 9: A PZM 1560 modified with two side boundaries at 45 degrees on each side. It provides additional side
discrimination from the loudspeaker cluster at Ambassador Auditorium.
Conclusion
This rather quick review of the development of multi-boundary PZMs has undoubtedly missed readers’
developments that may be important and unique. Forward them to Crown. Include pictures or drawings to illustrate the idea and the technique utilized.
There are still many yet-to-be discovered ways that these PZMs can be used; many configurations of
multi-boundary PZMs yet to be developed. The one principle I’m sure of is that PZMs can provide
some microphone pickups that no other microphone can yet accomplish.
LETTERS FROM PZM USERS
PZMs improve conference miking
At a J.C. Penney corporate headquarters meeting room, I saw an odd-looking round device on a
table. It was a conference microphone made by another manufacturer. We suggested they try a PZM
for comparison. They did, and will buy two PZMs! They loved them.
Two years ago, a German magazine research company set up an office in New Jersey. I suggested
they use the PZM, but they thought they couldn’t afford it, and bought two conference microphones of
another manufacturer. Later the research company called to say that the microphones were terrible
and wanted to try the PZM. I gave him one for three days. They reported that his German business
associates heard them and were delighted! He ordered three more PZMs!
The head of the audio-visual department at J. Walter Thompson wanted to try a PZM taped to a l2foot-high ceiling. I told him he should get the prize for unusual usage of PZMs. He said “I knew they
were good but this blew me away!” He bought it.
Sam Helms, Metrorep, 57 South St, Freehold, N.J.
PZMs great for drum reinforcement
I play in a Top-40 band, and recently started using PZMs in live sound reinforcement. I’m using two
inside a large plexiglass barrier for my drums. I place them low and in the corners facing out I also use
one conventional unidirectional microphone overhead in the center, and one on top of the snare
drum.With this setup, I get incredible low end from the toms and bass drums, great highs from my
cymbals and Rototoms, and I only use four channels on the main board. The barrier also cuts down
my stage volume.
Mark L. Wright, Las Cruces, N.M.
Fig. 10: PZM drum miking.
Reply:
Thanks for your notes on PZM techniques for drums. We’re glad you were able to simplify your drum
miking. Some other techniques worth trying are:
*A PZM-30GP [now the PZM-30D] on your chest to pick up the kit.
*Two 30GP [PZM-30D] overhead, back-to-back, for cymbals.
*A GLM-100 clipped onto the snare-drum rim.
###
PZM MEMO
October 1984
Bruce Bartlett, Senior Editor
Ken Wahrenbrock, Contributing Editor
CROWN PZMs ENHANCE BUDDY RICH RECORDING
Tate-Reber Productions, headed by Gary Reber, recently recorded the Buddy Rich Big Band with
extensive use of PZMs. Digital recording equipment was supplied by Abbey Road Studios. The recording will be released in Beta Hi Fi, VHS Hi Fi, analog disc, and Compact-Disc formats.
For overall quad pickup of the band and audience, Gary devised an eleven-foot-wide PZM boundary
array made of 4’x 4' plexiglass panels. The front mics of the array picked up the ensemble, while the
rear mics picked up audience reaction.
In addition, Gary used two PZM Dishes [discontinued] over the drumset, a PZM-2.5 [discontinued] in
front of the kick drum, and a pair of PZM-6S [now the PZM-6D] units underneath the lid of the piano.
In all, eleven PZM-6S and four PZM-2LV were employed. Bass was taken direct and miked off the
amp.
The mix was processed through a Tate quadraphonic encoder/decoder system, which permits panning of tracks anywhere around the listener.
Gary will describe the setup in full detail in future issues of STUDIO SOUND and MIX, and in the next
issue of PZM Memo [Mic Memo]. Watch for this outstanding recording later this year.
PZMs RECORD HOUSTON SYMPHONY
Dove & Note Recording Company, Houston, Texas, recently completed a recording session with the
Houston Symphony Orchestra. Dove & Note suggested PZM applications, supervised the overall
project, did the recording engineering and performed the live stereo mix.
The album material was large-scale classical works performed by the 97-piece Houston Symphony
and the 225-voice Sanctuary Choir of Second Baptist Church, Houston. They were conducted by Gary
Moore, Minister of Music of the church.
Digital Entertainment Corporation, Nashville, supplied a 32-track Mitsubishi X-800 Digital Studio
Recorder; Digital Services, Inc., Houston, provided the remote studio facilities; Crescendo Corporation, Dallas, underwrote the project, and Sparrow Records, Los Angeles, will distribute the recording.
Album release is expected in September.
PZM ON PANEL
I’ve been a sound recording engineer since 1945 (PRE-TAPE). First with AFRTS from 1946-56 and
sicne 1956 to the present with theMotion Picture/TV Dept. at Rockwell International-NAAO (nee
NorthAmerican Aviation.
I’m sure that you’ve had as many ideas for the use of the PZM as there are audio people who write
you. About a year ago, I put together a plexiglass boundary plate for use with our mic stands. We took
some pictures and I am enclosing a set for your interest. Since that time I see you now have one on
the market [discontinued.] I’m sure I was not the only user to come up with the idea.
Fig. 1: PZM-30GP and PX-T on paper-covered plexiglass boundary.
Not long ago I was on location for a Rockwell project to record sound for one of our company films at
an Air Force base. Much of my time there was spent about 200 feet from the main runway. I mounted
a PZM on the side of an Air Force van which was parked parallel to the runway (see photo), to see
what would happen as the various jet aircraft took off and landed on that runway.
Fig. 2: PZM-30GP taped to side of van.
The results were amazing. I used a Nagra III with a multi-step attenuation pad in the mic line. The only
distortion was the natural distortion associated with a jet engine operating at the dB level. The sounds
were recorded mono. I only wish I had a Nagra IVS. While the sound will not transfer to 16mm optical
with that purity, I at least know that the original recording is good.
It would seem that the uses for the PZM are limited only by the imagination. It’s nice to hear “clean”
noise.
Martin Halperin
Audiovisual Program Coordinator
Motion Picture/TV Department
North American Aircraft Operations
Rockwell International Corporation
Los Angeles, California
Fig. 3: Velcro strips hold PZM to panel. Atlas AD-11 flange is screwed to panel. It accepts a tube that fits into a
microphone stand adapter.
PZM ON DISK FOR MIKING CHOIRS AND ORCHESTRAS
Here’s the best way I’ve found to mike a choir/orchestra to achieve maximum gain or reject nearby
sound sources.
1. Cut out a 24"-diameter disk of 1/4" acrylic plastic and polish the edges (see figure).
2. Mount a flange on top of the disk in the center.
3. Screw a gooseneck into the flange. The gooseneck allows leveling of the disk.
4. Mount a 6LP [now the PZM-6D] to the bottom of the disk.
5. Splice the mic cable inside the gooseneck with grey Belden 8451.
I have suspended lengths up to 45 feet without problems.
Fig. 4: PZM on suspended acrylic disk.
RESULTS:
1. More available gain than actually needed! Previously this was unheard-of for a choir.
2. I’m able to reinforce the choir sound back to the choir via an overhead monitor with success. In
other words, the choir can actually hear themselves via the monitor - also previously impossible.
3. We achieve excellent rejection of “above plate” sound sources; pipe organs immediately above the
choir are not additionally amplified.
4. We get the usual PZM benefits. Since there’s a greater area of blending, we can use fewer PZMs
than we would need using cardioid condensers. There’s better spectral pickup of off-axis voices;
therefore better, more natural reinforcement. Choir directors love them.
5. You can hang them via the mic cable without tie lines, fishing line, etc.
I don’t care what [theory] says; placement of the element near the center of the disk produces no
audible problems for sound-reinforcement uses. [Editor’s comment: The response problems caused
by that placement occur only for sources on-axis in a “dead” environment.]
Glen C. Collins, P.E. Allied Sound, Inc.
Nashville, Tennessee
PZM PULPIT MIKING
I need some help concerning monitors, using a PZM as a pulpit microphone. I never have enough
gain before feedback.
Fig. 5: Customer’s PA setup.
The sketch will give you an idea of the pulpit area. We currently use a Neumann KM84, but would like
to eliminate the gooseneck, etc., associated with the Neumann. Please respond with any helpful
information.
Also, can I make the PZM wireless? I have an HME wireless system.
Dale Bettany, Sound Technician, Bethesda Temple, 21960 Fern, Oak Park, Michigan 48237
Reply:
Feedback is sometimes a problem with PZMs because placing them on a surface also places them far
from the sound source. The farther the microphone, the less the gain-before-feedback. The same
problem occurs with any microphone placed far from its source.
Here are some suggestions:
*Raise or build-up the pulpit surface so it’s closer to the talker.
*Try wiring the two monitor loudspeakers in opposite polarity, and place them exactly equidistant from
the PZM. This arrangement partially cancels the monitors’ sound at the microphone, letting you increase the gain-before-feedback.
*Using a graphk equalizer in the monitor channel, cut frequencies that feed back.
*Try mounting the PZM capsule/holder on an angled boundary. This is an L-shaped, 60-degree angle,
clear acrylic plastic corner reflector that makes the PZM directional. It’s designed for use with the
PZM-6LP and PZM-6S [now the PZM-6D] microphones.
*With the angled boundary, the best monitor location might be behind the microphone (the audience
side of the pulpit), if you can place the monitors there.
*You can make your own corner boundary out of wood or plastic. The bigger the boundary, the better
it works. Big boundaries have more bass and better rear rejection than small boundaries. So make the
biggest boundary that is not visually conspicuous.
*Try a Crown PCC-130W, which is a small supercardioid boundary mic.
MULTI-BOUNDARY PZM FOR THEATER
“Brighton Beach Memoirs” just played the Fisher Theatre with PZMs in the footlights, mounted in a
homemade Isoflector-like shield - but with the mic mounted backwards (see below).
[Editor’s comment: This arrangement can be improved by mounting the capsule holder so that the
“nose” or front of the capsule holder touches the vertical boundary. This avoids phase cancellations
and improves rear rejection.]
Fig. 6: Incorrect placement of capsule holder in angled boundary.
ORCHESTRA RECORDING WITH PZMS ON A PANEL
Since this summer’s purchase of two Crown PZM mics we have been in a state of recording bliss!
The difference between these two little mics and any combination of traditional mics we’ve used is
truly remarkable.
Among several concerts so far recorded with PZMs, we had excellent results recording Bach’s Cantata 106 and A. Honneger’s oratorio “King David.” Both performances included orchestra, organ, and
full choir with soloists (instrumental and vocal).
We mounted the PZMs back-to-back on a 18" square plexiglass plate, placed several feet above and
behind the conductor’s head. We obtained a balance and clarity unmatched - even with complex
microphone placements and mixings of the past. So, besides being excellent microphones, they
considerably reduce the time to prepare for a major recording project.
We do have a couple of problems, however. They don’t work with every recorder or mixer I have. Is it
possible to add a line transformer to boost the signal so it will work with my Yamaha K-960 or
Nakamichi BX-2, for instance? Since (alas) I must still haul my equipment all over the place, I prefer to
use cassette decks over the large open-reel machines (when top quality is not of greatest concern).
Also, since we record a good bit of choral music, we have had some complaints of over-emphasized
“essing.” Is there such a thing as an “ess-filter?”
Stephen Heller, Department of Music, Moravian College, Bethlehem, PA
Reply:
You can add a line transformer to boost the signal. The transformer must be connected between the
phantom power-supply output and your recorder input.
There is a signal processor called a ‘De-esser” (a form of compressor) which reduces sibilance without affecting tone quality. Ask your sound dealer. Unfortunately, it requires line-level signals and is
expensive.
Some PZMs (30G, 6LP) [now the PZM-30D and PZM-6D] have an emphasized high-frequency response for brilliance. If you have either of these models, they may be causing your sibilance problem.
Try a PZM-31S or PZM-6S [now the PZM-30D and PZM-6D] which have a flatter high-frequency
response.
PZMs CAPTURE STOCKHOLDER’S MEETING
Industrial Communications of Detroit used seven PZMs in Isoflectors for the dias on GM stockholders’
meeting. We felt it was a stunning improvement over last year’s setup.
Lester J. Hamilton, Fisher Theatre Sound Dept., Union Lake, Michigan
YOU TURKEY!
I recorded a Thanksgiving dinner using two PZMs taped to the turkey. The carving was particularly
dramatic. You can actually hear the difference between light and dark meat!
Christopher S. Johnson, CBS Educational and Professional Publishing, New York, New York
[Editor’s comment: No comment]
PZMs IN BAFFLES AID PICKUP OF A MEETING
Recently we were contracted by the local Alcoholics Anonymous Club to help with their meeting room.
They were using a powered lectern that everyone could hear. But when members of the audience
near the front responded to the moderator, no one in the rear could hear them, since they were facing
the front. Adding to this problem was a large electrostatic smoke precipitator (hung from the ceiling)
which emitted a rumble in the rear of the room.
SOLUTION: We built four plexiglass right-angle baffles (see figure), mounting 6S elements snug into
the corners of the baffles. We located the PZMs for maximum coverage of the front two-thirds of the
audience.
Fig. 7: PZM mounting in angled baffle.
We also located the ceiling speakers toward the rear, and hooked them in series-parallel to present 8
ohms to each channel of the Hafler DH-220 amp.
The other components used in this chain were a Ramko P4 mixer, a Crown PH4 [now PH-4B] Phantom Power Supply, and a Range GE-27 ½-octave equalizer.
Fig. 8: Mic and speaker layout at meeting.
The results were terrific.. .no feedback with the EQ set, and plenty of volume in the rear of the room even with the smoke precipitator running. The club is so delighted that we were contracted to do three
other meeting rooms in the Atlanta area.
Thomas M. Hayward/Rick Rogers, National Sound Engineering, Atlanta (Lilburn), Georgia.
###
PZM MEMO SUPPLEMENT
October, 1984
Bruce Bartlett, Senior Editor
Ken Wahrenbrock, Contributing Editor
1984 PZM CHALLENGE WINNERS
Judging has been completed for this year’s PZM Challenge. It was the third annual contest to determine the best original recordings made with Crown PZMs as the main microphones.
The PZM Challenge is divided into two categories. The “Dealer” contest is open only to Crown PZM
dealers, their employees, and immediate families. The “Open” contest can be entered by anyone
except Crown dealers. Ineligible entrants are Crown employees, sales reps, and advertising or publicrelations agents.
Based on the recordings’ sound quality and creativity in the use of PZMs, winners are determined in
each of three categories:classical, popular, and environmental. The winners from each category
receive their choice of a pair of PZMicrophones. A Grand Prize winner is then selected for each contest from the category winners. Each of the two Grand Prize winners receives a choice of two pair of
PZMicrophones and a PZM accessory. Runners-up from each category receive one pair of PZM
model 180 microphones.
Judging took place on June24, 1984. The judges had long experience in critical listening. They were:
Dr. Clay Barclay, New Product Manager, Crown International. Clay is also a former high-end audio
dealer and recording engineer.
Bruce Bartlett, Microphone Design Engineer and Technical Writer, Crown International. Bruce is also
editor of the PZM Memo, a contributing editor to Modern Recording & Music, and a recording engineer
and musician.
Tom Lininger, Microphone Department Manager, Crown International.
This year’s entries numbered twenty-six. They were uniformly high in quality; we regret not being able
to award more entries. On separate forms, we scored each entry on a scale from 1 to 10. both for the
overall sound quality and for creativity in the use of PZMs. The scores were entered into a computer,
which averaged the results and indicated the winners.
THE WINNERS
Dealer Challenge
Grand Prize In the Dealer Challenge, Popular Category:
ALFRED GRUNWELL and TODD HUTCHINSON. Calf Audio, Ithica, New York; for a recording of folk
singer Mark Rust.
Winner in the Dealer Classical Category:
RICHARD MENASCO, Tallahassee, Florida; for a recording of “St. Nicholas.”
Winner in the Dealer Environmental Category:
JACK FLANINGAN, Triad Audio Systems. Inc.. Fort Wayne, Indiana; for a recording of a steam train.
Runner Up in the Dealer Popular Category:
DAVID MENASCO, Tallahassee, Florida; for a recording of “When I’m 64.”
Runner Up in the Dealer Classical Category:
RICHARD MENASCO, DAVID MENASCO. and MICHAEL
LOWHORN, Tallahassee, Florida; for a recording of “The Messiah.”
Runner Up In the Dealer Environmental Category:
DAVID MENASCO, Tallahassee, Florida; for a recording of rain and birds.
Open Challenge
Grand Prize In the Open Classical Category:
GARY PILLON, Detroit, Michigan: for a recording of “Christ the King Chorale.”
Winner, Open Popular Category:
JIM WILKE, Seattle, Washington: for a solo piano recording of Adam Makowitz.
Winner, Open Environmental Category:
HERB CHALLIS, Ormond Beach. Florida: for a recording of a space-shuttle liftoff.
Runner Up, Open Popular Category:
LEROY SHYNE, Shyne Sound, San Rafael, California; for a recording of three gospel groups.
Runner Up, Open Classical Category:
ANDRJEZ LIPINSKI, Glen Echo. Maryland: for a recording of Vivaldi’s “Four Seasons.”
Runner Up, Open Environmental Category:
FRANK SERAFINE. Serafine FX Inc.. West Los Angeles. California; for a recording of jets at the
Denver airport.
Thanks to everyone who took up the challenge. and congratulations to all the winners. Let’s discuss
each winning entry in detail.
Mark Rust - “Our Families Came to Sing”
World Records, Toronto
Grand Prize, Dealer Popular Category
Engineered by Alfred Grunwell and Todd Hutchinson
Calf Audio, Ithica, New York, 1983
Produced by Bill Usher
This record of folk music sounded open, airy, clean, and well defined. It was well balanced tonally and
very well mixed. The creative recording techniques used in this recording are described below by
engineer Alfred Grunwell, a three-time PZM Challenge winner:
“Philosophically, we (and the producer) like to record all instruments simultaneously for both musical
and economic reasons. (Most of the instruments] were cut live, with the musicians separated by
goboes (baffles] that were sound-absorbent on the bottom, and reflective plexiglass on top. We have
them set up in an “X”, all very close together, good eye contact, playing very softly. With normal mics
this is hopeless, because generally you need to push the mics in very tight to get enough gain. All we
did was tape a pair of PZMs to the tops of each gobo in each artist’s station and roll!
Mark Rust session setup.
On one tune the musicians were so soft that we had the PZMs all the way open - no pads - and the
faders on the board pushed all the way up. It was great - a nice, bright, airy sound, no sweat. No EQ
was used on recording or mixdown.
All instruments on this record were recorded in stereo - usually a pair of PZMs.”
More of Grunwell’s techniques will be covered next issue.
“Harold Schiffernan’s St. Nicholas”
Performed by a woodwind quintet.
Winner, Dealer Classical Category
Engineers: Richard Menasco and David Menasco, Tallahassee, Florida
A very natural, realistic recording of a woodwind quintet, with pleasant ambience and stereo.
The setup, shown below, included two PZM-31S [now the PZM-30D] on the floor near a fieldstone
wall behind the ensemble; and a PZM-3OGP and 6LP [now the PZM-6D] hung on 2' x 2' plexiglass in
front of the ensemble.
St. Nicholas session setup.
765 Steam Train
Winner, Dealer Environmental Category
Engineered by Jack Flaningan, Triad Audio Systems, Inc., Fort Wayne, Indiana
A clean, realistic recording of a steam train, with full stereo motion well-captured by the PZM array.
The recording was made one-quarter mile from any roads, along a wooded stretch of an old Norfolk &
Western track outside New Haven, Indiana. Two PZM-3OGPs [now the PZM-30D] were located ten
feet from the rails in a coincident-pair arrangement.
Lennon & McCartney’s “When I’m 64"
Runner Up, Dealer Popular Category
Engineered and performed by David Menasco, Tallahasse, Florida
This is an amazing re-creation of the Beatles’ tune, made by multiple digital overdubs. Water glasses
are cleverly substituted for chimes. Each instrument sounds natural. The mix is clean and well balanced, with good use of stereo. The lack of hiss after 12 generations speaks well for the digital recording process!
The tape contains recordings of thirteen individual performances. Along with each performance, a
tape of the preceding performances was played, and the sum of these signals was recorded on a
stereo recorder. Thus, the tape has a 13th-generation copy of the bass part, and a 12th-generation
copy of the snare drum part.
Noise buildup was avoided by recording on a Technics SV-P100 digital audio cassette recorder and a
Technics SV-100 digital processor with a Toshiba VCR. The only effect used was the three-band EQ
on the Tapco C-12 mixer, used sparingly.
[Here are the old Crown mic models mentioned below and their current equivalent models:
2LV = GLM-100
6LP = PZM-6D
30GP or 31S = PZM-30D]
The microphone setup was as follows:
BASS:Direct to mixer.
SNARE DRUM AND BACKING VOCAL: 2LV clipped to shirt, 6LP out front on stand, panned left and
right for stereo.
GUITAR AND BACKING VOCAL: 2LV on stand for vocal: 6 LP on wall for guitar amp.
UPRIGHT PIANO: 6LP on stand for bass strings; 2LV on stand for treble strings, panned left and right
for true stereo.
THREE BACKING VOCAL TRACKS: 2LV on mic stand, panned for stereo.
CYMBALS: 2LV on stand over hi-hat; 2LV on stand over cymbal.
BASS CLARINET, FIRST CLARINET, SECOND CLARINET:
6LP and 2LV on stands, left and right, with 31S in center for bass clarinet only.
To achieve the effect of a three-piece combo, David placed the mics for stereo pickup, then positioned
the bass clarinet near the right side, the second clarinet near the left side. and the first clarinet near
the center.
WATER GLASSES: See figure below.
LEAD VOCAL: (and first clarinet on first four and last four measures): David sang about a foot away
from the wall into the same array used on David Menasco’s recording of birds and rain (described
later).
“When I’m 64" session setup.
“Birds and Rain in My Backyard”
Runner Up, Dealer Environmental Category
Engineered by David Menasco
This is a natural stereo recording containing a low-frequency rumble characteristic of the city environment. The microphone array shown below was hung by nails on the back wall of David’s house.
“Birds and Rain” mic setup.
Handel’s “Messiah,” an Oratorio in Three Parts
performed by the Tallahassee Symphony at the Ruby Diamond Auditorium Tallahassee, Florida
Runner Up, Dealer Classical Category
Engineered by Richard W. Menasco, David Menasco, and Michael Lowhorn
This is a subtly multi-miked recording of a large classical ensemble. We heard a smooth, full-bodied
recording with a competent mix of all the instruments and voices. The setup is shown below:
“Messiah” microphone placement.
“Christ the King Chorale concert”
Recorded at Christ the King Church, Detroit, MI
Grand Prize Winner, Open Classical Category
Engineered by Gary J. Pillon
The recording was clean and clear, with a well-balanced blend of the orchestra, soloist, chorus, and
ambience. Although the soloist was picked up at a distance, she was reproduced with amazing presence and immediacy.
Engineer Gary Pillon describes the recording technique:
“For two months beforehand, I was busy pulling all the pieces together for this singular event. General
Television Network supervisor, Chris Allen, was very supportive. He authorized the use of a JVC
BR6200 VHS portable deck, Earthtone location mixer, and other support equipment. One of our VTR
operators, Paul Feinberg, donated his pair of PZM 6LPs [now the PZM-6D] along with a plexiglass
wedge measuring 2' x 2', angled to give a capsule spacing of approximately 9 inches. Interestingly
enough, a piece of video hardware supplied a solid base for the microphones. A Mole-Richardson HiRiser, normally used to support 5000-watt lights, enabled the wedge to fly almost 15 feet above the
audience.
The church has fairly good acoustics, so the microphone placement was a matter of finding the one
“sweet spot” at the nearfield boundary. In this manner an acoustic balance was struck between the
choir and orchestra musicians, letting the wedge capture the event, rather than individual sources.
“Christ the King Chorale concert” mic setup, top view.
“Christ the King Chorale concert” mic setup, audience view.
Once I placed the microphones at their critical distance in the church, I joined the bass section of the
choir, and engineer Loren Mathers took over. We had set up our Technics SV-100 Digital Encoder,
supplied by Hy James Inc., for maximum headroom.
At this point, Alexander Broude Inc. graciously consented to clear the music for the PZM Challenge,
and an analog transfer from the digital elements was supervised by Ed Wolfrum of Audio Graphics in
Royal Oak. The Otari MTR 10/dbx-1 analog copy is virtually identical to the Technics master, and
provides “best seat” perspective to an excellent performance.
I would like to thank everyone concerned for their hard work, and to offer this entry in the spirit of
cooperation that helped create it.”
“Adam Makowitz, Solo Piano Concert”
Performed at the Seaffle Concert Theatre, Seattle, Washington
Winner, Open Popular Category
Engineered by Jim Wilke, Seattle, Washington
This is a solo piano recorded closeup in stereo - a suitable perspective for pop music - with natural
reproduction of piano timbre and dynamics.
Jim attached two PZM-3OGPs [now the PZM-30D] to the underside of the piano lid. No other mics
were used. The recording was broadcast on non-commercial radio.
“Three Gospel Groups”
Recorded at Dominican College in San Rafael, CA
Runner Up, Open Popular Category
Engineered by Leroy Shyne, Shyne Sound, San Rafael, California
Here’s a well-balanced mix with clear cymbals and well-controlled ambience.
The concert was recorded at the sound-reinforcement mix position (in an outdoor ampitheatre) with
two 31S mics. The choir microphones were two Wahrenbrock PZM-150s mounted on 4'
x 2' pieces of plexiglass, angled to reject the monitors behind the boundary plane (see figure below).
The piano microphone,a 6LP [now the PZM-6D], was mounted on the closed lid. Drums were covered
by a Wahrenbrock PZM-150 on a mic stand overhead.
“Three Gospel Groups” mic placement.
“Vivaldi’s Four Seasons - Autumn”
Flute Version - Performed by the Polish Radio & TV Chamber Orchestra
Jadwiga Kotnowska, Flute; Agnieszka Duczmal, Director
Baroque Catholic Church in Pozanan, Poland
Runner Up, Open Classical Category
Engineered by Anchjez Lipinski, Glen Echo, Maryland
This delightful recording had a warm, smooth tonal balance; an appropriate perspective, and wellbalanced stereo. The beautiful, lively hall acoustics gave the recording a ‘commercial” sound.
Engineer Lipinski won an honorable mention last year. He describes the recording as follows:
“The place of the recording was a balcony of the Baroque Catholic Church in Pozanan, Poland. I
accepted as the best possible place for two PZM-3OGPs [now the PZM-30D], 5 to 6 feet apart on a
wide handrail of the balcony. Then I asked the soloist to move behind the orchestra. Finally I added
one coincident stereo mic as a spot for the soloist. and recorded it on separate tracks before
mixdown.”
“Jets at the Denver Airport”
Recorded at the Stapleton Airport in Denver
Runner Up, Open Environmental Category
Engineered by Frank Serafine, Serafine FX Inc.
This recording earned high points for creative usage of PZMs as well as sound quality. As shown in
the figure below, Frank Serafine placed PZMs on the front and rear windshields of his ’79 Olds Cutlass for stereo pickup. He recorded their signals with a Sony PCM-F1 Digital Recorder.
“Jets at the Denver Aiport” mic placement on car windshields.
A jet flying low over the microphones was heard as an enormous scream from speaker to speaker practically blowing out the tweeters. Yet the recording was undistorted.
Another environmental recording that almost tied with the “Jets” tape deserves mention. Reynold
Weidenaar recorded pigs at a feeding trough with a pair of PZMs set on concrete pavement 8 feet
apart, directly in front of the feeding trough. Disgustingly real!
The PZM Challenge was a lot of fun to judge this year. The overall quality of the recordings was quite
high. so we found it difficult to rank them. Many lost only by default to the top entries.
Thanks to all the entrants for your efforts. The winning entries will be played at the Crown booth at the
October AES Show in New York. Many thanks to all who participated.
###
PZM MEMO
January 1985
Bruce Bartlett, Senior Editor
Ken Wahrenbrock, Contributing Editor
CROWN INTRODUCES PCC-160 PHASE COHERENT CARDIOID
PCC-160
Soon to be available from Crown is a new, unidirectional microphone meant to be used on boundaries
like the PZM.
The Crown PCC-160 (Phase Coherent Cardioid) is a surface-mounted supercardioid microphone
intended for professional applications on stage floors, lecterns, conference tables, and news desks.
When used as a “footlight” microphone for drama. musicals, or opera, the PCC provides louder,
clearer sound pickup than previous microphones.
Technically, the PCC-160 is NOT a PZM. The diaphragm of a PZM is parallel to the boundary (a
patented feature): the diaphragm of the PCC-160 is perpendicular to the boundary.
We mention the PCC in the PZMemo because it gains much of the same benefits from surfacemounting as does the PZM. Also. those PZM users who need a directional model but would prefer not
to work with plexiglass boundaries have another option.
The PCC is not a replacement for the PZM. PZMs are preferred in applications where you need a
uniform hemispherical pickup, a shapeable polar pattern, corner mounting, 150 dB SPL capability, or a
flat response down to 20 Hz.
Like the PZM, the PCC is designed to be used on a relatively large boundary surface. Unlike the PZM,
the Phase Coherent Cardioid uses a sub-miniature, professional quality supercardioid mic capsule.
The unidirectional polar pattern increases gain before feedback, reduces unwanted room noise and
off-axis pickup.
Since the microphone capsule is placed on a boundary, direct and reflected sounds arrive at the
diaphragm coherently, or in-phase. The benefits are a wide, smooth frequency response free of phase
interference, excellent clarity and reach, and a “half supercardioid” pattern (based on the hemisphere
created by the large boundary plane).
Self-contained electronics eliminate the need for an in-line preamp box. The PCC-160 may be phantom powered directly from the console or other remote power source providing 12 to 48 volts. A “bass
tilt” switch allows the user to tailor the low-end response for particular applications.
Thanks to its low profile and charcoal grey finish, the microphone becomes almost invisible in use.
The heavy-gauge all-steel body protects the unit from accidental abuse. Capable of withstanding up to
120 dB SPL without distorting, the PCC will never overload in practical use. Its electret condenser
capsule provides a frequency response from 50 Hz to 18 kHz. Sensitivity is very high (-53 dB re 1 volt/
microbar) and self-noise is low (less than 22 dBA).
Production units are expected to be available in January 1985 at a suggested list price of $249. For
more information, contact Customer Services Dept., Crown International, 1718 W. Mishawaka Rd.,
Elkhart, IN 46517.
In a few months, Crown will also introduce the PZM-2.5-FM [discontinued], which uses 18-inch-high
plexiglass boundaries to achieve directionality. How does the 2.5 compare to the PCC? The 2.5 has
lower self-noise and better rear rejection of high frequencies. The PCC has better rejection of low-tomid frequencies, requires no plexiglass boundaries, and has a three-position bass-tilt switch.
WHERE’S THE MICROPHONE?
The following is a true story from Bill Raventos, Microphone Product Manager at Crown.
A woman reported that her school’s PZMs were stolen. She showed up at Crown carrying three PZM
carrying cases, saying ‘This is all that’s left of them.”
Bill opened the cases. In each one was a PZM-30GP and a power-supply interface.
“What was stolen?” Bill asked.
“The microphones,” she replied.
Bill took out the 30GP and explained, “This is a microphone.”
“Oh... Never mind.”
PZM-180s SIMPLIFY MICROPHONE TECHNIQUES
Brian Coviello of Hoffman’s Music in Spokane. Washington appreciates the simplicity of using PZMs in
stereo live recordings.
He used two PZM-180s [now the PZM-185] back-to-back to record a live concert in Calvary Chapel.
The mics were hung over the center of the balcony.
The concert blended live vocals with a pre-recorded instrumental track. PZMs also contributed to the
instrumental track, with 3OGPs [now the PZM-30D] used for percussion and for string ambience
(taped to the control-room window). Mixdown engineers at Whitefield Studio in southern California
were impressed with the PZMs’ sound.
Brian’s live recording was released on MRC records. a label featuring contemporary Christian music.
LETTERS FROM PZM USERS
PZM studio techniques
The following is an excerpt from a letter by Alfred Grunwell of Calf Audio, a grand prize winner in the
1984 PZM Challenge:
One of the great benefits of PZMs is that they greatly expedite the setup procedure. For those used to
taking a lot of time in setting up, it’s astounding. Placement does make a difference, but it is dramatically less critical than with normal mics...
One comment we hear from time to time, and must collectively dispel, is that PZMs tend to sound
harsh on acoustic instruments. In my opinion, there’s some other problem, and not the mic. For example, if you’re recording an Ovation acoustic guitar (the kind with the plastic back, popular for live
playing) with PZMs, then the sound will be bright to the point of thin and/or harsh. But in this case, it’s
the instrument, which is generally acknowledged as great for live work but inappropriate for recording
because of this reason.
On all our vocal work, we use whichever standard mic sounds best on that particular voice, have the
talent sing toward the control-room window (which has a PZM-6LP [now the PZM-6D] on it), and mix a
little delayed PZM sound in on the track. It really opens up the vocal sound by giving it both air and
brightness, precious commodities in contemporary recording. And because it’s a PZM and used in
small proportion, there’s no ugly comb filtering... All multiple-person sections are always done with a
stereo pair of PZMs.
Fig. 2: Grunwell’s drum-miking technique.
On the drums we’re developing more techniques and trying to make them totally PZM while maintaining the standard low, deep studio sound. So we’ve come up with this: We have a “flying V” plexiglass
unit that we use for stereo overheads with PZM-6LPs. We usually use a 6LP [now the PZM-6D] in the
kick and on the high-hat. Our newest breakthrough is to tape the PZMs onto the top of the kick, directly under the mounted toms. And voila: more great sound, bright but deep, lots of attack and plenty
of air.
Alfred Grunwell, Calf Audio Inc., Ithica, New York
More on Grunwell’s techniques next issue.
PZMs help record “Pilot” LP
We used the PZMs for drum ambience (two-wedge configuration), vocal ambience, and sound effects
on the first LP released through Rain Records, entitled “Pilot.”
Band:Pilot, Rain Recording, Mt. View, Hawaii
PZMs for conference and audience
I work in a Media Services center at a college. We’ve purchased a PZM-3OGP, 6LP, and 2LV [current
models are the PZM-30D and PZM-6D].
Our primary use is in our TV studio (which is rather small and not totally soundproofed), and during
the video and audio tapings of small-to-large groups attending conferences on this campus.Here are
some situations where we could use help:
1. How do we get rid of the slight “echo” effect in the studio when using the 30GP or 6LP? [now the
PZM-30D and PZM-6D.]
2. What’s the best way to use PZMs when trying to get audience questions in auditoriums seating 250
and 600 people? (By the way, these people will seldom use aisle microphones set up for this specific
purpose,)
3. How do we avoid sometimes getting radio stations over the audio we are trying to tape?
Any other information from users of PZMs in similar situations would be more than appreciated.
Mikel-Jon Carter, AV Coordinator, Media Services, Bentley College, Waltham, MA 02254
Reply:
To reduce “echo” or reverberation, you can (1) sit closer to the microphones, (2) place the microphones closer to the participants, (3) deaden the studio acoustics with carpet on the floor and thick
curtains spaced from the walls, or (4) use a Crown PCC-160, a supercardioid boundary microphone.
The PCC-160 is unsuitable if the participants surround the microphone, since it rejects sound from the
rear.
To pick up audience questions, (1) try mounting a PZM-6LP [now the PZM-6D] on a 2' x 2' plexiglass
panel several feet above the front row of the audience, just in front of the front row. Aim the microphone side of the panel at the back of the audience. (2) Try one or more 6LPs on the ceiling over the
audience.
To reduce RFI, ground the mic cable shield directly to the mixer chassis. Also, you can install capacitors in the microphone line to shunt radio frequencies to ground. In the mixer mic connector (or in the
interface output connector), solder a .01 mF, 100V capacitor between pin 2 and 1, and solder another
matched capacitor between pin 3 and 1. Alternatively, solder a 470 pico farad, 25V capacitor between
pin 3 and pin 1 in the PZM cable connector (or in the cantilever). Use whatever solution works best.
I hope these suggestions solve your audio problems.
Rock recording with PZMs
With the advent of “new wave” and garage-band rock styles, the recording environments have become diverse and odd.
No longer are these bands satisfied recording one track at a time. Their emphasis is at least 90% live
in the studio, or wherever. Recording such bands requires innovative ideas (especially in small rooms
or clubs). PZM mikes can be very useful in recording rock instruments such as bass guitar. electric
guitar, and the full drum set.
Fig. 3: Mic setup for rock recording.
I know the microphone setup looks odd, but they work with minimal leakage and almost no phasing.
Both direct boxes and PZMs were used in combination with some Shure and Sennheiser mies. The
PZMs give a great full sound enhancement.
I would like to hear more on recording rock hands in small areas and small clubs. Thanks.
The Gang at Squantum, Squantum Sound, Perth Amboy. NJ
PZM for equalization
Used in conjunction with a White 140 Spectrum Analyzer, the PZM-30GP [now the PZM-30D] does a
great job in equalization for masking systems. (A masking system is a speaker system playing pink
noise to make conversations more private).
The noise spectrum was equalized to an NC-40 curve, which slopes downward between 63 Hz and 2
kHz. The PZM is flat in that range. I used the PZM in an open office area on a 2' panel at ear height
(4' off the floor). The PZM gives a much broader area of sampling and works much better than conventional instrumentation microphones in this application.
R.G. Heiser, Industrial Communication Co., Columbus, Ohio
Mics for film/video
I have several clients in the film and video sound business, and they have appliations for which PZMs
could be used.
I would like to see info from people with successful applications of PZMs for location recording of film/
video sound.
Kurt Albershardt, Paragon Sound, Universal City, CA
Reply:
For film/video applications, Crown mics are typically used as follows:
*CM-10 lavalier into a wireless transmitter.
*PZM-6D’s small plate mics) hidden on the set on tables, on props, on walls, behind flower pots, under
thin tablecloths, or on the floor.
*Form a “V” out of two sheets of clear plexiglass, 1 foot square by 1/4" thick. Place the “V” on top of
the video camera with the point of the V aiming at the sound source. Tape PZMs to opposite sides of
the “V” for stereo pickup. (This suggestion courtesy of Gary Pillon of General Television Network.)
Miking interviews with PZMs
I use my PZM-6LP for interviews. My business is making audio tapes for family histories. I put the
PZM on my large teak dining table, and we conduct the interview looking out on a fantastic view of
San Francisco. The PZM-6LP [now the PZM-6D] makes it easy for interviewees to relax and freeassociate.
Overall, the quality of the tape is very good. I have to be sure no extraneous noises will occur during
the two-hour session. I still have to experiment a bit on placement of the mic for a more even response.
David Angress of Sound Genesis suggested the PZM after he became self-conscious during an
interview using a traditional unidirectional mic.
I love receiving the newsletter, although I wish somebody was using PZMs for speech so I could
compare notes.
Adah Bakalinsky, Legacy Unlimited, San Francisco, CA
Violin miking
My idea concerns modifying a chin-rest clamp to hold a GLM vertically along the top edge of a violin.
This would produce (I think) a second boundary to add directionality to the pattern. I thought of this as
a way to use a GLM on stage with an Irish folk group. Any response would be greatly appreciated.
John Halliburton, Carbondale, IL
Reply:
Here are some suggestions on miking a violin with a GLM:
*Clip a GLM to the bridge.
*Put a strip of foam rubber in the clip teeth, and clip the GLM to the short strings behind the bridge.
*Clip the supplied GLM-UM Universal Mount to the tailpiece, and clip the other end to the GLM flex
relief. Position the GLM over an F-hole.
*Place a GLM inside an F-hole and EQ the signal to make it sound more natural.
*Try a GLM vertically mounted as you suggested.
You may want to record yourself with these different microphone placements, then play back the tape
over a hi-fi system to determine which placement sounds best. Also check each technique to see
which gives the most gain before feedback. Good luck!
###
MIC MEMO
April, 1985
Bruce Bartlett, Senior Editor
Ken Wahrenbrock, Contributing Editor
PZM MEMO BECOMES MIC MEMO
Why the name change? We’ve broadened our emphasis in microphone design here at Crown. Having
just introduced the PCC-16O, and with other surprises yet in store, we’ve changed the name of this
newsletter to the Mic Memo to reflect Crown’s broader approach to making interesting, technically
innovative transducers.
Look to these pages in future issues for more information on PZMs, and ALL of Crown’s new microphone products. As always, reader input is welcome!
HELP!
We need suggestions from PZM users on effective audio-pickup methods for location film or video.
This is a neglected area of PZM application. Send us a description of your techniques, and we II he
happy to publish the tips in the Memo.
Here’s one tip: Try a PCC-160 on the floor or on a table near the action. Its half-supercardioid pattern
should help reject background noises and room acoustics.
PZMS COVER OUTDOOR BAND TOURNAMENT
KPHO TV, Phoenix, has developed a unique application for PZMs: pickup of the Fiesta Bowl National
Pageant of Bands. The show and setup are described below by Mark Voorhees, a maintenance specialist and project engineer at KPHO.
In 1983, KPHO began producing this program for national distribution by Broadcast Communications,
Inc. The event is an invitational marching band competition in conjunction with the FIESTA BOWL
football game, with bands traveling from around the country to perform in the 3½ hour live show at
Sun Devil Stadium, Arizona State University, Tempe, Arizona.
KPHO TV, a division of the Meredith Corporation Broadcasting Group, was contracted by the Fiesta
Bowl National Pageant of Bands to produce the television special, hosted by NBC “Today Show”
personality Willard Scott. The telecast is a one-hour edited version of the live show, including one
performance by each participant band.
The engineering challenge involved devising the best audio pickup possible, capable of maximum
quality and versatility. The stadium is outdoors, and, to make matters worse, on the approach pattern
of a major airport. The fact that many stadium seating areas were to be kept empty added to the audio
difficulties.
Our approach was to use the large-plate PZMs (Model 3OGP) [now the PZM-30D] for field pickup of
the bands, as well as audience reaction. We determined that our area coverage required twelve PZMs
for the stadium field, and two for crowd sound.
Since we wanted the most directional control, each PZM was mounted on a 3/8" thick, two-footsquare clear Lexan panel which was mounted (adjustably) to the top of a ten-foot pole, which we
could then mount temporarily on a fence post at the edge of the field. Additionally, the crowd mics
were mounted on the back of two of the center-field mics. (The custom mounts were developed by
KPHO Mechanical Engineer Vernon Prue). The use of the Lexan made the installations almost invisible. See Figures 1 and 2.
Fig. 1: A single-panel PZM mount. Ten of the mic positions were ouffitted with ths mount.
Fig. 2: The dual-panel mounting placed at north a south 40-yard lines.
We chose to aim the PZMs to the working field area, and adjusted position and tilt accordingly. Fixed
percussion instruments were picked up using cardioid dynamic mics, so that coverage could be limited. See Figure 3 for mic placement and aiming.
Fig. 3: Placement of the PZMs on the stadium field. Aiming direction and elevations are indicated.
This arrangement created a “sound dome” over the field area, providing good overall coverage and
good left-right separation. The PZMs rejected background noises and aircraft quite well.
The bands played to the main spectator stands at the west side of thestadium. We wanted less pickup
at the east side so that, when the band turned away from the audience, the level dropped. This provided an audible cue that the band was aiming away. The object was to convey the motion and dynamics of the bands, rather than a constant-level coverage.
This year’s efforts were an expansion of our first use of these mics last year. We learned from that
show that our original placements (for 8 mics) and mounts had to be changed. “Holes” in coverage
plagued our first use of this method, but overall quality was good.
We were very pleased with the PZM performance during taping this year. Although this year’s show
was released in monophonic sound, the entire production was recorded in field-mixed stereo, with
appropriate placement of the panning controls on the Audiotronics console. As expected, the noises
and dead echoes were virtually eliminated; the performances were crisp and clear with outstanding
pickup of solo elements within the bands.
Band directors who screened the final shows from 1983 and this year have complimented us on the
unmatched quality of the audio pickups. We look forward to using the PZMs on this and other projects
in the future.
FOR KPHO TV:
Engineering Supervisor: Walter Beatty
Engineering Audio Supervisor: Mark Voorhees
Engineering Audio Mixer: Robert Carter
Engineering Audio Mixer: Richard Kohler
Remote van provided by TCS Communications, New Kensington, PA.
LAS VEGAS HILTON SHOW BAND USES PZMS
by Ken Wahrenbrock
Hilton Music Director Dick Lane and Sound Engineer Steve Rypka were so pleased with their first
tests of PZMs that the request was “purchase them.” Two PZM-D-3s are used for the trumpets and
two more for the woodwinds. The woodwinds include two players with flutes, clarinets, and saxes.
Piano is miked with a PZM-6S [now the PZM-6D].
The drum kit is screened with plexiglass on three sides. A PZM-6S is placed in front of the bass drum
on the plexiglass. A PZM 2LV [now the GLM-100] is being tested for close pickup on the toms and
snare if needed.
The percussionist is wearing a PZM-2LV for 95% of his pickup. An additional mic is stand-mounted
over a tom. Since his instruments are surrounding him about 270 degrees, he provides the properdirection pickup as he turns to play that particular set of equipment. One sound effect using a boat
whistle did not sound right the first time. He realized that the mic was now below his mouth on his
chest, so he turned the whistle over to radiate downwards.
Steve Rypka is exploring other uses of PZMs with the band and expects to utilize some other PZM
versions in the future. In testing the PZMs, Dick and Steve sought clarity and accuracy. The PZMs
delivered.
PZM ORCHESTRAL RECORDING SOUNDS WONDERFUL
Gary Pillon, a sound mixer for General Television Network just sent in a very impressive PZM recording which was up for a local Emmy nomination. It is a live mix of “The Messiah,” performed by the Fort
Street Chorale and Orchestra on December 8, 1984. The recording venue was a cinderblock-andwood church dating back to the late 1800’s - a marvelous acoustic space.
Performers included 75 choir members, a 2~piece orchestra, and four soloists. The original mono
audio fed a 5-camera video remote truck hired by WTVS, the local public TV station. Channel 56 was
taping the event as the capstone of a 1/2-hour documentary about the choir.
Gary used two stereo pairs of PZM-6S’s [now the PZM-6D]. A 60-degree wedge was placed about 8
feet behind the conductor, even with the overhead chandeliers, out of camera view except for an
extreme wide shot.
In addition, a stereo 2.5 (designed by Mike Lamm of Dove and Note Recording in Texas) was placed
on “apple boxes” and sandbags just behind the conductor. It picked up the sound coming directly from
the orchestra and augmented the soloists, who stood on each side of the Maestro, facing the 800
people who packed the two levels of the church.
Gary also sent a June ’84 recording of The Christ the King Chorale, augmented by a 22-piece cham-
ber orchestra. He used a bipolar PZM (two PZMs back-to-back on a 2-foot boundary) about 17 feet
over the conductor’s head. Equipment included a dbx 700 Digital Processor and a Beta Hi-fl video
deck.
To our ears, the recordings sounded spacious, with a full stereo spread, good localization, and a midaudience perspective. The acoustics suited the music well. Tonal quality was full and smooth, and the
balances among the orchestra, choir, and soloists were just right. This recording could have been a
PZM Challenge winner.
According to Gary, “PZMs really do the job and have a sound that is all their own - the sound of real
life.”
PZMs CAPTURE AUDIENCE AS PERFORMERS
Another intriguing recording was sent in by Ron Streicher, a well-known recording engineer with
Pacific Audio Visual Enterprises. Ron has presented several practical papers on recording techniques
at A.E.S. conventions.
His tape was a recording of “Treatise” by Cornelius Cardew, performed by the AUDIENCE of the
Monday Evening Concert at the Bing Auditorium of the Los Angeles County Museum of Art, on January 7, 1985. Audience members played toy instruments while interpreting the slide-projected score
(examples shown below).
Sample of projected score for music recorded by Ron Streicher.
Another sample of the score.
The recording mics were PZM-150-Ds (made for Ron by Ken Wahrenbrock in 1978), which were
placed on the walls in the four “corners” of the auditorium (front left and right, back left and right) to
surround the audience. Immediately adjacent to each microphone was a loudspeaker system; these
were used to play the recording back to the audience immediately after its performance.
Speaker/microphone layout for Ron Streicher’s recording.
Ron reports: “This performance recording gave me, finally, the opportunity to do something I have
wanted to try for a long time.. to record an environmental “happening” and then to immediately play it
back in the same environment, from the same perspective as it was recorded. Since I was situated in
the middle of the audience (where I was operating the recording/playback system for the concert), I
was in a good position to evaluate the correspondence of the recording to that of the original performance.
It was a remarkable experience! As I had expected, the sounds recorded seemed to be reproduced
with an uncanny relationship to their original locations in the hall. I cannot tell whether this was true for
all participants in all locations, but it was so for me.”
The sound we heard was indeed quite natural, and we could sense the mirth of the performers as they
concocted their own responses to the graphic images of the score.
USING PCCs FOR STAGE LECTURES
The figure below shows a stage arrangement for public group discussions. At the rear of the stage is
a sofa and coffee table; on either side of the stage are two round tables, and at center stage is a
lectern.
A Crown PCC-160 (supercardioid boundary microphone) is placed on the coffee table to pick up the
participants on the couch; another is used on the lectern shelf top. If the participants at each round
table surround the microphone, a PZM can be used. Otherwise a PCC is preferred for more gainbefore-feedback.
PCC/PZM placement for stage lectures.
LETTERS FROM PZM USERS
PZMs great for piano, kick drum
In July we purchased a new Tokai piano. We had been using Shure SM-57s to mike it, however, I
wanted to experiment with PZMs. I finally settled on placing the 3OGP [now the PZM-30D] flat on a
piece of foam on the stand that holds the short and long stick. The piano lid reflects the sound down
into the PZM, and combined with the direct sound Wow! Clear, clean, natural, crisp - with NO added
coloration.
A PZM-31S [now the PZM-30D] is great in a kick drum. Again, natural sound with no coloration, and
ability to withstand the high SPL.
I have learned not to be alraid to experiment with PZMs. You are only limited by your mind - not the
mic!
Bill Wood, Christ Covenant Church, Greensboro, NC
PZMs for studio drums
I’m a drummer in a local studio around Memphis, TN. In my sound-proof box where I record, we
recenfly installed PZM microphones. I’m glad to say that it is the best sound I’ve ever gotten out
of a microphone. I’m proud to say that Crown is the best sound you can get when you’re “ready for
real.” Thank you, Crown; you’re the best.
Derick Kemp, Dirt Music Co. Clarksdale, MS
Hiding PZMs
I would like to conceal PZMs for use in industrial films, but have been unable to find out how to use
them in this situation. Also, have you printed anything about ENGIEFP uses? Have you considered
selling a manual based on your PZMemo?
Zack Schindler Madison Heights, MI
Reply:
Available at no cost is the Crown Boundary Microphone Application Guide, which includes many
PZMemo applications. You can order one from Crown or your Crown dealer.
Here are some suggestions on concealing PZMs:
1.
Clip a PZM-3LV [now the CM-10] lavalier to the shirt under the tie. Boost high frequencies on
your mixer to compensate for the tie’s high-frequency rolloff (unless this boost makes clothing noise
objectionable).
2.
Put a PZM-6S or PZM.6LP [now the PZM-6D] on tables, under tablecloths, behind props, or on
walls.
For elecfronic news gathering:
1.
Use a PZM-12SP [now the PZM-185] as a handheld interview mic, or place it on a desk or
table for seated interview.
2.
3.
Use a PCC-160 on a desk or table to reduce background noise and off-axis pkkup.
For ambient pickup on location, tape a PZM to the side of the news van.
Sound Grabber output pad
I just purchased a pair of Sound Grabbers and am very pleased with their striking clarity and (sensitive) response to very (quiet) sounds. However, because of their high output, they overloaded the mic
inputs on my open-reel deck. A simpIe in-line voltage divider can be made from a couple of I k ohm
resistors. This will reduce the output so they won’t overload the mic inputs.
I have used these mics with musical material with good results. Thanks for a fine product at an economical price.
Russell C. Campbell, Ferndale, WA
SPECIAL PZM FOR FLUTE
by Ken Wahrenbrock
Charlotte Blount is professor of classical flute and baroque flute at USC, California. Her husband
Gilbert is professor of harpsichord there. They have combined talents to present concerts on classical
and baroque flute in many places.
Most halls they have encountered require some reinforcement for the flute to balance the harpsichord
volume. Charlotte has found that a stand microphone and most lavalier mics are unable to provide
faithful reproduction. Gilbert has used a PZM for the harpsichord and enjoyed the PZM’s fidelity. He
contacted Ken Wahrenbrock to see whether something could be done for the flutes.
A 2LV [now the GLM-100] cantilever with a 15-foot cord was mounted on a small bar 5/16" X 3/4".
Velcro was mounted on the flute and on the base of the bar. This arrangement spaced the PZM from
the body of the flute to place the sound entry of the PZM even with the raised emboucher of the flute.
Careful placement of the PZM is required to find the sweet spot so that the reinforced sound faithfully
reproduces the sound heard by the musician’s well-trained ears.
This special PZM was compared to several other microphones (including other small electrets). The
judgement by careful listeners was “no comparison.”
More testing is planned for the wooden baroque flute to find a microphone with the same transparent
reinforcement. The PZM for the metal flute does not quite “cut it,” even though it is superior to all the
other mics tested.
###
MIC MEMO
October 1985
Bruce Bartlett, Senior Editor
Ken Wahrenbrock, Contributing Editor
USING PZMs TO RECORD THE BUDDY RICH BIG BAND
Fig. 1: Buddy Rich Band at King Street Studios.
We’re proud that Crown PZMs were selected to preserve a performance of one of the biggest names
in jazz: Buddy Rich and his big band. An alltime great drummer with masterful technique and tremendous drive, Buddy currently heads the pre-eminent big band in the country.
Bogue-Reber Productions of Los Angeles, in association with One Pass Productions of San Francisco, produced a Buddy Rich Band concert video special on One Pass’s King Street Studios
Soundstage, April 2 and 3, 1985. Crown PZMs were used extensively in this major production.
The two-hour specials were titled “Mr. Drums: The ‘Channel One’ Set and the ‘West Side Story’ Set.”
The programs were licensed to:
Pioneer Artists (a division of Pioneer Video) for worldwide Laserdisc digital-sound videodiscs. Sony
Corporation for worldwide Beta Hi-Fi, VHS Hi-Fi videocassettes, and Video-8 with digital sound. Cafe
Records by Mobile Fidelity Sound Labs (Original Master Recordings label) for two compact discs, two
audio cassettes, and a specially packaged threerecord set.
The project was produced in association with the Bravo Entertainment Network as a pay/cable TV
special, and for the Discovery Music Channel.
Gary Reber was Producer. His credits include the SQ/Tate System surround-stereo soundtrack production of David Bowie’s “Serious Moonlight” and “Dolly Parton in London” HBO specials. Steve
Michelson, President of One Pass, was Executive Producer; and Scott Ross, Vice President of One
Pass Operations, was Director. Ken Rasek of Chicago was the Digital Surround Stereo Soundtrack
Mixing Engineer.
Conceived by Reber nearly a year ago, the project was meant to define the state of the art in film-style
high-tech video production. The 8-camera Ikegami shoot used the revolutionary SQ/Tate surroundstereo system. The event was supported by equipment manufacturers whose reputations for cuttingedge technology are renowned.
In the King Street Studios, the livingroom-size control room was transformed into a Soundex-treated
digital-audio recording/mixdown control room. Equipment included a Yamaha 2000 recording console
and a 16-channel SQ/Tate System position-encoder console to create the final “live-to-two-channel”
encoded surround-stereo mix.
The Tate/SQ position encoder contains 360-degree, fixed-position pan pots which enable the mixing
engineer to assign dialog, instrument, music or effects to a specific spatial location (or pan for motion).
To further enhance the signal transparency and transient definition of the Buddy Rich rhythm section,
special BBE processing was applied to those input channels just ahead of the Tate/SQ position encoder. No other equalization or processing was applied to the mix, except for slight soundfield reverberation produced by a Lexicon Model 200 Digital Reverberator.
To capture the full dynamic range and transient power of the Buddy Rich Band, Reber chose Crown
Pressure Zone Microphones for their accuracy and transparency, and AKG “The Tube” microphones
for their warmth.
Fig. 2. Buddy Rich
Fig. 3. Microphone layout for Buddy Rich band session.
Four AKG “The Tube” microphones were placed for intimate pickup of trumpet, trombone, and saxophone soloists. Additionally, four Countryman Isomax II Condenser Microphones were clipped to the
flutes of the musicians who play saxophones and double occasionally on flute. Buddy’s announce
microphone was a Shure 5M87.
The rhythm section, horns, and ambient surround were recorded with twelve Crown PZM microphones (PZM-315 and PZM-65) mounted on specially designed and surface-treated plexiglass boundary arrays. These arrays were configured by Reber and Vince Motel, the project’s PZM Application
Engineer. Bruce Bartlett, a Microphone Project Engineer at Crown, was consulted about boundary
acoustics and array design.
The entire wiring requirements for the soundtrack production were met by Monster Cable Prolink
Interconnect Cables and Prolink High-Performance Studio Microphone Cables, assuring pristine
signal quality in the transmission from microphones to mixing consoles to recorders.
Storage of the mix was on a combination of state-of-the-art analog tape recorders (by Nagra, Studer,
and Ultra Master) and digital audio processors (by Sony and JVC) coupled to Sony BVU U-Matic
video tape recorders.
The result: A state-of-the-art, SQ/Tate System surround-stereo soundtrack presentation displaying full
dynamic range, wide channel separation, and exceedingly low distortion and noise. The recording had
extraordinary transparency and accuracy.
As Reber states, “The objective was to capture the”live” essence of the Buddy Rich Band concert
experience for replay on videodiscs, videocassettes, analog records, cassettes, compact discs, and
stereo television broadcasts.”
“The equipment chosen for this production produced a quality of audio delivery to make sound real
and dimensional. When replayed through a Tate Surround-Stereo System consumer decoder through
a four-channel audio system, the stereo soundtrack is transformed; and the listener is enveloped
within an entire sound field, just like the “live” experience enjoyed by the audience at the concert.
That’s our purpose: To put you there.”
The opinions expressed in this article are those of Tate-Reher Productions and do not necessarily
reflect those of Crown International.
PZMs ON RECORD
Heard any PZMs on disc lately? Crown is collecting the names of any compact discs or analog LPs
that were recorded with PZMs.
One such recording is “Pan Is Beautiful III,” an outstanding yecording of a steel-band contest (covered
next issue). Another is Frank Zappa’s recording with the London Symphony Orchestra.
The best we’ve heard yet is a jazz-fusion compact disc, “Tricycle” by FIlm and the BB’s, on DMP
records. High-impact drums, piano and sax are picked up with PZMs, along with synthesizers and
Alembic bass. Terrific demo material.
If you know of any records using PZMs, or if you’ve made a commercially released record using them,
please send the record titles to Bruce Bartlett at Crown.
THE PROBLEM-SOLVING PCC
Crown PCC-160s greatly improved the sound reinforcement in a gymnasium/ auditorium at Bethel
College in Mishawaka, Indiana. The microphones picked up a stage production of an original musical,
“Joseph.”
As shown in the figure below, three PCCs were strategically located on a 20’x 40' stage. The gym was
100' deep by 70' wide, with cement block walls and a hardwood floor.
Fig. 5. PCC stage miking.
All three mics were on simultaneously. Although this procedure decreases gain-before-feedback
compared to muting unused mics, the gain was sufficient. There was no need to ride the microphone
faders.
The PCC-160 has a supercardioid pickup pattern with a small rear lobe, and maximum sound rejection (nulls) at 135 degrees off-axis. The sound engineer used this knowledge to advantage when
aiming the mics.
For example, note the piano four feet behind the left-side PCC. When the rear of the microphone was
aimed at the piano, the PCC picked it up slightly. But after rotating the mic to “null out” the piano, the
piano became inaudible through the reinforcement speakers.
As in any theatre sound system, actors who didn’t project were harder to hear. Additional microphones
(PZMs) might be suspended to reinforce rear-stage dialog in future productions.
According to the sound engineer, past setups have always had problems, but the PCCs provided the
best sound in years. The reinforced sound was quite intelligible - despite the gym’s cavernous acoustics.
The South Bend Tribune reviewer praised the show’s sound quality: “The production also is enhanced
by an excellent sound system which does justice to the music.”
Ken Kuespert, a freelance sound engineer, tried PCCs for a recent stage production of “Brigadoon” at
Lakeshore High School in Stevensville, Michigan. Five PCCs were placed as shown in Figure 6: three
across the front of the main stage and two on the thrust stage.
Fig. 6. PCCs on stage.
Ken rode gain on the microphones. He often had GAIN TO SPARE - practically unheard-of in stage
miking. The tone quality was natural; the foot noise was minimal.
In another installation, a user reported that he tried a PCC in his marble-floored church, with amazing
results: A PCC on the floor provided more gain-before-feedback than the standard lectern mic on a
gooseneck!
We don’t expect this result too often, and have encountered installations where only a gooseneck mic
will work. Success or failure depend on the room acoustics and sound system. Still, it’s gratifying that
sometimes the PCC can work so well.
The PCC is a good mic for a lecturer or minister who wanders while speaking. With a gooseneck mic,
the distance from the talker to the microphone varies greatly as the talker moves, because the gooseneck mic is close to the talker. As a result, the microphone output varies greatly. But a PCC is relatively far from the talker, so its output varies less as the talker moves.
A PCC-160 was used on the TV show “Airwolf,” which features a high-tech helicopter. The mic was
placed on the ‘copter’s dashboard to pick up the pilots’ dialog. Since the PCC also looked “high-tech,”
it was left in view for the camera shots!
Wedding recording is another application where the PCC is ideal. Just put it on the floor near the
ceremony. It will provide highly intelligible pickup without detracting from the proceedings.
HOW TO USE A PCC WITH A NEWS DESK
Television directors dislike lavalier mics. These clip-on microphones are visible on-camera; they can
be inconvenient to attach to clothing (especially females), and the cord is subject to much abuse.
The PCC-160 Phase Coherent Cardioid is a viable alternative to lavalier mics in news-desk applications. It picks up approximately the same amount of background noise and room acoustics as a
lavalier mic. Yet, it is invisible on-camera and causes no problems with attachment or cables. A PCC
also can be used as a backup microphone if a lavalier mic fails on the air.
One-to-three people can be picked up with a single PCC.
Try to mount the PCC as shown below. Place it two feet or less from the talent to reduce ambient
pickup. Mount it on a shelf or ledge several inches above the main desk to reduce pickup of paper
shuffling. Many news desks include such a ledge in front to hide the TV monitors.
Fig. 7. News desk miking with a PCC-160.
Putting the microphone on a shelf also prevents the talent from laying papers on top of the mic. If
papers are placed on the microphone, high frequencies are greatly reduced and the response becomes very rough.
On the camera side of the shelf is a small ledge to hide the PCC. The microphone should be spaced
at least twice the ledge height away from the ledge to avoid degrading the polar pattern.
You may want to pad the desk top with 1/8" foam rubber or felt to dampen table taps.
If a raised shelf is unacceptable, place the PCC directly on the news desk and put some thin foam or
felt on the table top in front of the microphone (not on the microphone plate) to reduce table taps. The
foam does not significantly affect the microphone’s frequency response.
Do NOT place foam under the microphone. Foam under a PCC acts as a shock amplifier, not a shock
isolator! In addition, raising the mic off the desk top roughens its frequency response.
With these precautions, you should achieve a clean pickup with no microphones in sight.
The PCC also has applications in radio. The figure below shows a PCC on an announcer’s table
beside the DJ’s console. Such an arrangement is an improvement over a gooseneck mic for inexperienced interviewees. One PCC covering two people picks up less room acoustics than two PCCs.
Note the acoustically absorbent material on the wall behind the announcers. It absorbs room reflections to make a “tighter” sound.
Fig. 8. PCC picking up an interview.
LETTERS FROM PZM USERS
Invisible microphone
As producer of the annual awards banquet for the Academy of Magical Arts, I am always faced with
what magic to include which will entertain and fool an audience of some of the world’s top magicians.
One of the hits of the last two years was my “Invisible Microphone” at the podium. I pretended to
adjust it as I would with a normal podium mic, but I was really using a PZM-6LP. No one could figure
out how the sound was being picked up so well - even when there were two or three people at the
podium. To make the PZM invisible I covered the back with silver metalized mylar tape.
WARNING: When used on a podium, there is a danger of people laying scripts and plaques OVER
the PZM. Position it at the top of the podium to minimize this risk.
Audience miking with PZMs
Writing in reply to the letter from Mikel-Jon-Carter in the Jan.’85 PZMemo, dealing with audio situations in his T.V. studio at Bentley College of Waltham, Mass. One of his questions concerned using
PZMs to mike an audience.
I do audio for a talk show aired weekly on local cable television. Our program is called “Citizen News
on the Air” and is hosted by Stephen Chace-Bass. “CNA” airs every Monday evening on the publicaccess channel in Long Beach, California.
We’ve used PZMs available to us over a year. I’ve learned not to use them for miking talent because
they work too well, picking up clothes rustling, construction sounds from the building next door, etc.
Several recent programs have featured an in-studio audience (albeit no more than fifteen people). I
placed the audience seats around a low table below camera range, and a PZM on the table. I instructed the audience to ask questions from their seats, and explained that it was not necessary to
speak louder or lean towards the table.
As a result, I was able to keep the PZM gain down, avoiding excessive ambient sound and retaining
enough headroom for soft-spoken audience members.
Sound Grabber works great
We have purchased two of your Sound Grabbers from DAK Industries in California to record our
family therapy sessions for our clients. One mic is usually placed on the floor in the center of the
room. It has worked so well that we have failed to consider the possibility that there might be a better
placement. The reduction in background noise amazes us.
In addition, we also utilize them to record our vocal octet and our wind ensemble along with other
musical functions in the community. Again, they are usually thrown somewhere on the floor out of the
way, and give exceptional balance and sound quality. We have discovered they usually provide the
best presence if they are within ten feet of a small group and 15 feet of the larger groups.
I find their capacity unbelievable, having spent ten years as the Supervisor of Recording at
Interlochen, Michigan with the best condensers available at the time. I am turning out recordings on
my home equipment equal to what used to happen with Ampex and Telefunken equipment.
You might be pleased to note that I will be taking your mics and my home machine to Italy with the
MSU Alumni Band tour. The quality of my demo tapes has assured us that at least one of our local
PBS radio stations will be airing those tapes upon our return.
Gary Wakenhut Lakeview, Michigan
More gain-before-feedback
In a large church auditorium, we want to get more gain before feedback, and less importantly, more
feedom of movement for the talkers. The present mikes are AKG 202E5 super-cardioids mounted on
a pulpit and a lectern. Thirty feet directly overhead are an Altec multicellular horn and a bass-reflex
speaker (crossed-over at 500 Hz).
Would the gain before feedback improve if we replaced the pulpit and lectern mikes with PZM-2.5s, or
use a pair of PZM-3LV clip-on’s (or have you other suggestions?). I suspect the talkers would prefer
clip-ons, but feedback control would be sacrificed due to the mike positions changing as the talkers
moved about.
We like the acoustics as they exist; the precedence effect is good and we wouldn’t want to lose it by
moving the loudspeakers forward. The main room ring modes have been suppressed by LC filters in
the speaker line, and the horn has been aimed and cells stuffed for equal-level dispersion.
T. Wickstrom St. Paul, Minn.
Reply:
Try a PCC-160.
Miking percussion with a PZM
I am a percussion player. In exploring your literature and PZMemos, I haven’t found any in-depth
coverage of PZM use in a live set-up like mine.
I perform in a four-piece band (guitar, bass, keyboards) in lounges, clubs, and our own converted
garage/studio.
My set-up includes three congas, a table for handheld percussion (similar in size and height to an
ironing board), a rack approximately 50 inches long with stationary bells and blocks, hanging gongs,
metal tubes 3 to 5 feet from the floor, a snare drum, and a cymbal stand.
I am essentially caged by my noise toys. It seems that a major problem with PZMs in this situation
would be ambient and incidental sounds. I would like to receive any tips and info you or your readers
might have. As far as I can tell, you guys have an amazing product.
Charles Lowrey, Self-Generated Productions, Nashville, Tenn.
Reply:
The usual method of miking a large percussion set-up with PZMs is to strap a PZM to the
percussionist’s chest. The microphone follows the percussionist as he or she moves from one instrument to another. Since only one mic is used there is little ambient pickup.
An alternative is to mount PZMs on several Crown A240 Boundaries. The A240 [no longer available]
is a 2’x2' clear plexiglass panel to which a PZM can be attached to make the microphone dfrectional.
Included with the A240 is a rugged, adjustable stand adapter for mounting the panel to a mic stand.
Aim the microphone side of the panel at the instruments, and aim the opposite side of the panel at the
sound-reinforcement speakers. Use as few panels/mics as possible to cover your set-up.
###
MIC MEMO
January 1986
Bruce Bartlett, Senior Editor
Ken Wahrenbrock, Contributing Editor
ANNOUNCING THE CROWN GLMs: GREAT LITTLE MICROPHONES
Fig. 1. GLM-100 microphone.
Crown is proud to present two new additions to the microphone line: The GLM-100 miniature omnidirectional mic, and the GLM-200 miniature hypercardioid mic.
Both GLMs are miniature electret condenser microphones designed for professional recording or
sound reinforcement. They offer all the quality of larger studio microphones, yet are nearly invisible in
use.
GLMs can be clipped or taped onto an acoustic guitar, sax, or flute to allow the performer freedom of
movement They can be attached to drum rims to pick up a drum set without the unsightly clutter of
boom stands. Suspended over a choir or orchestra, or hidden on a film set, they disappear in use yet
provide excellent sound quality.
Frequency response is wide and smooth: 20 Hz to 20,000 Hz in the omni GLM-10O; 60 Hz to 20,000
Hz in the hypercardioid GLM-200. Other benefits include excellent transient response, minimal off-axis
coloration, and very high overload level (150 dB SPL peak).
The GLM output is balanced, low impedance, which allows long cable runs without hum pickup or
high-frequency loss. The microphone connects directly to a 24-48 volt phantom power supply; no
additional interface is required.
The hypercardioid GLM-200 has excellent rejection of off-axis sounds (over 25 dB at the rear nulls);
this rejection is uniform with frequency. The hypercardioid pattern increases gain-before-feedback and
reduces pickup of room acoustics, background noise, and unwanted sounds behind the microphone.
When used as a lavalier microphone, the GLM-200 rejects background noise and room acoustics
compared to a conventional omnidirectional lavalier.
The omnidirectional GLM-1OO is recommended for extended low-frequency response, lower noise,
and all-around pickup (say, for drum-kit miking with just two or three microphones.)
Included with the GLM is an all-purpose mic clip for mounting the microphone, a tie bar and belt clip
for lavalier use, and a windscreen. Optional accessories allow mounting on various instruments [no
longer available]. Several GLM application notes are available from your Crown dealer.
PZMs IN TELEVISON PRODUCTION
Gary Pillon, a sound mixer for General Television Network of Oak Park, Michigan, is a pioneer in
television-audio applications for the PZM.
Gary won the 1984 PZM Challenge, worked on the Detroit region ITVA Golden Cassette winner and
took home the first local Emmy for field audio (for the syndicated PBS program “Miracle on Fort
Street”).
He was invited to the International Film and Television Workshops last June in Rockport, Maine as a
teaching assistant, specializing in showing the many uses of PZMs in film and video recording. After
reviewing the basics, Gary played his Emmy-winning recording of the “Messiah,” which was very well
received.
The class then went into a field test arranged by the teachers, New York sound mixers Mark Dichter
and Helene Kaplan. A cover shot of a seated, table-top, three-person role play was set up. They
recorded this situation with a Schoeps hypercardioid, a Sennheiser shotgun, three Tram body mikes,
one PZM-6S [now the PZM-6D], and the Schoeps set up on a table mount.
When Gary played back the Nagra recording over IMF speakers, the differences became quite apparent. According to the class, the PZM track was the best-balanced and most lifelike of this particular
test. The other major contender was the table-mounted Schoeps, which costs over three times as
much and cannot be hidden under a tablecloth or prop.
They also recorded on the Rockport dock in an open phone booth. The overhead boom could not get
in the right place to record dialog, so Gary put a PZM-6S capsule into the corner of the glass shroud.
According to the students, the quality of the pickup was startling, and this test further increased interest in the mics.
This summer Gary also constructed a prototype stereo PZM 2.5. Cutting out pieces of foamcore, he
built a device resembling two 2.5 mics joined along their long end (see Figure 2). The assembly could
be stand-mounted from the backside or hand-held if necessary.
Fig. 2. Pillon stereo PZM.
The stereo image, which is partly a result of the 8" capsule spacing, is designed to be like that produced by a binaural recording, but with more-realistic playback over loudspeakers. Ideally, this device
would mount on a Steadicam platform and give an excellent match between audio and video perspective. [The current version of this mic is the Crown SASS-P MKII.]
A different version of the stereo 2.5 has been designed by Mike Lamm and John Lehmann of Dove &
Note Recording in Houston, Texas (see Fig. 3). Gary sent us a variety of recordings made with the
device since its construction for the Messiah concert. The demos he sent us were made with this
“floor model” and a Sony Walkman 6C Pro. As Gary says, “You can take the Lamm and Lehmann
floor array, set it down, and just roll. You get a very close approximation of the real event.”
Fig. 3. Lamm and Lehman floor-mount stereo PZM.
One recording was made in a rock club with the stereo 2.5 inverted and hung from the light bar over
the band. This was not a “tight,” commercial-sounding record, but rather an accurate recording of how
a rock band sounds from the audience - a distant perspective. With the tape playing at full volume
over headphones, you really feel part of the audience!
Another recording was made with the Lamm and Lehmann (L2) array on the floor ofthe band room of a
similar group. A comparison of the two recordings confirms what you might expect: the suspended
mics had less bass and more highs, while the floor-mounted mics reversed the balance.
A third tape of the Christ the King Chorale used a unique microphone technique for classical-music
recording of an orchestra and choir Gary formed a PZM wedge by mounting a pair of PZMs on 2-footsquare panels with edges touching (as in Figure 4). Two bungee cords anchored the wedge from the
top of a Mole Richardson Hi-Riser placing it 17 feet high and 10 feet behind the conductor on the edge
of the near-field boundary. In addition, Gary placed the L2 floor array 8 feet behind the conductor (See
Figure 3). This setup was first used on the Messiah concert.
Fig. 4. PZM wedge placement.
Because of rehearsal delays, he had only one minute to obtain a balanced mix before this concert, but
it worked. To our ears, individual instruments and voices sounded articulate and clear without being
harsh or overbright. Hall ambience was pleasant and full. Stereo images were clearly localized and
the stereo spread was natural. Blending of the orchestral and choir sections was excellent.
We congratulate Gary Pillon on his Emmy award and thank him for sharing his PZM techniques with
us.
PZMs RECORD STEEL-DRUM FESTIVAL
Hayden A. Hart, director of Electronic Services Limited, sent us an outstanding recording they had
done of the “1984 Pan Is Beautiful II” Steelband Music Festival in Trinidad, West Indies.
We heard an open, airy, natural sound; with very wide dynamic range and good imaging. The recording captured the full range of timbres from delicate to piercing. Cymbals sounded smooth, and the low
bass was phenomenal.
The goals for the recording were described by Mark Coffey of Texas Pacific Film & Video of Austin,
Texas, paraphrased below:
Our theory is that distant miking, rather than close miking, best captures the sound of a steel-drum
orchestra. This premise is based on the qualities of the individual pan and the overall sound produced
by multiple instruments of the same tonal range.
Pan has an imperfect quality: When a note is struck off-center there is usually a brittle, noise-like tone
that contrasts to the roundness of the primary tone. Close miking picks up every off-center hit. Because sharp sounds lose their energy faster with distance than round sounds, distant miking would
hear more tone and less attack.
In addition, groups of steel drums never can be perfectly in tune because of the imprecise tuning
method. When large orchestras play, the slightly out-of-tune instruments give rise to a whole other
sound.
The out-of-tune notes beating against one another create a shimmering effect, which helps give pan
its uniqueness. It sounds something like a Leslie organ speaker.
To fully record the shimmering effect, the mics should be placed some distance from the sound
source. I come from the school of thought that says air mixes sound better than electronics. The
interaction of the instruments playing live can be captured only by using distant miking.
Trying to duplicate this sound by close miking would result in the sound of 100 pans playing together
instead of 100 pans playing as one. And it’s this fullness, this power that is the excitement of a steeldrum orchestra and is the sound we want to record.
For the recording of each steel-drum band, Electronic Services Limited used four Crown PZMs: one
PZM-30GP two PZM-6S, and one PZM-6LP [now the PZM-30D and PZM-6D.] These mics were
placed on a 2' x 2' sheet of plexiglass, except for the 6S’s placed on 4' x 4' sheets. They were positioned to capture the most important sections of the orchestra.
Note that there is no standard placement of steel band instruments for classical performance. As a
result, Electronic Services Limited did much preliminary work to determine exactly where the instrument sections were to be located, so that the mics could be properly positioned.
Shown in Figure 5 is a sketch of the microphone placement for the winning band, Amoco Renegades.
Fig. 5. PZM miking of a steel-drum band.
Mic 1: PZM-31S
Mic 2: PZM-31S
Mic 3: PZM-30GP
Mic 4: PZM-30GP
Mic 5: PZM-30GP
Mic 6: PZM-6LPB
The entire recording was closely monitored on-site and captured on a Thscam 34 eight-track recorder
using dbx noise reduction equipment. It was then mixed down to a dbx Model 700 digital processor.
Mark Coffey evaluated the recording as follows:
“Having been present for the recordings at the semi-finals and the finals of the “1984 Pan Is Beautiful”
Pan Festival, I am encouraged that the knowledge to record these instruments properly is developing.
Although I would like to experiment further with mic placements, Mr Hart’s “surround” technique is
based on sound principles.
I think the use of a minimum number of separate tracks is very helpful in gaining a proper balance
among the sections. I continue to like the use of PZMs as the main recording microphones but I could
see experimenting with a more-directional close-miking technique, say for the bass pans...
These recordings have both presence and depth, power and subtlety. For the Merrytones the bass
pans are really standout; giving their calypso punch, definition and power. These are the qualities that
must be captured to have a really effective recording...
Overall, I think these recordings are the best I’ve heard thus far.
REDUCING RFI IN THE PCC
The PCC-160 has built-in protection from radio-frequency interference. If you are using the mic in an
area with an extremely strong AM-broadcast-band signal, you may want to replace the .002 uF capacitors on the output connector with 0.1 uF capacitors. The audio response at 20 kHz will be down 3
dB, but any AM pickup should be eliminated.
LETTERS FROM PZM USERS
Mounting PZMs on boundaries
I enjoy receiving the Mic Memo for the excitement and creativity surrounding the use of PZMs that you
bring out each issue.
I use a Radio Shack PZM taped to a piece of plexiglass for recording interviews with Laotian refugees. I glued a piece of foam rubber to the bottom of the plexiglass boundary. The interviewees simply
rest the affair in their laps, against their chests. After reading one of your issues, I glued another piece
of plexiglass to the foot of the first, gaining better rejection of background noise and slightly higher
sound pressure levels.
Though I discovered PZMs through Radio Shack, I’m about to become a true believer and step up to
a Crown PZM-30GP!
Kevin Merrell Boise, Idaho
Reply:
Thanks for the idea, Kevin. Before you try a PZM-30GP (now the PZM-30D], note that its cantilever is
not detachable from the plate. You may want to try a PZM-6S [now the PZM-6D] which has a removable cantilever.
It’s important to place the “nose” of the cantilever against the vertical plexiglass panel to prevent
phase cancellations. To achieve this arrangement you might try cutting a notch in the plexiglass to fit
the PZM plate.
Combining two PZMs into one input
We are using three PZMs and love them! Two on a large pulpit are super for voice and one on our
grand piano, taped to the underside of the lid - super!
I would like to know about combining the two PZMs on the pulpit, used for PA, into one phantompowered input. Can I do it without loss of sensitivity? We use an Altec preamp model 1690 so we
have plenty of power for the mics. Can I just parallel the connections? I have two PZM-6LPs with two
PX48 interfaces.
At present, we are using two inputs of the 1690 for this one location. I want to retain both PZMs at
their present locations; a single unit reduces gain and flexibility.
Reply:
Paralleling the PX48 outputs will work, but it will reduce each mic’s sensitivity by 6dB. (The same is
true when any two microphones are paralleled.) With the parallel connection, the load impedance
seen by each interface is 150 ohms.
If the interfaces are paralleled, the resulting 150-ohm load may result in distortion with high-SPL
sources. To prevent distortion, solder a 270-ohm, 1/8-watt resistor in series with pin 2 and pin 3 in
both female connectors in your Y-adapter (a total of four resistors).
With this circuit each interface will see approximately a 1000-ohm load. The sensitivity still will drop 6
dB when the interfaces are connected together.
Fig. 6. Mic combiner circuit.
PZM use
I have used the nice PZM-6LP for concerts and for the TV recording studio at the Theater Yaguez and
Channel 3-AS. Thanks, Crown International, for the good mics and equipment.
Jaime Ruiz, Supervisor Sound Technician, Theater Yaguez, Mayaguez, Puerto Rico.
PZM theory
In the Dec.’85 issue of Guitar Player magazine was an excellent article on personal studios. The
article states that PZMs are constructed to pickup only primary [direct] sound waves, and reflect other
waves away from the mic capsule. Is this correct? Also, a figure shows a PZM on a mic stand several
feet in front of a guitar amp. Is this a proper placement?
Reply:
PZMs pick up both direct and reflected sounds, in phase with each other at all frequencies in the
audible band. This provides two benefits: (1) It doubles the microphone sensitivity. (2) It eliminates
phase interference between direct sound and sound reflections from the boundary on which the PZM
is mounted.
PZMs are meant to be used on large boundaries; otherwise the low-frequency response shelves down
6 dB. Placing a PZM on a mic stand may give the desired sound, but you risk losing low-frequency
response and creating phase interference from floor reflections.
###
MIC MEMO
August 1986
Bruce Bartlett, Editor
GLM TECHNIQUES FOR RECORDERS (WOODWINDS)
Fig. 1. Suggested GLM placements for a recorder.
Here is a suggested technique for miking a recorder with a Crown GLM-100 mini omnidirectional
condenser microphone.
For the most natural tone quality with sound reinforcement, you can mike a recorder with a GLM-1OO
as follows (please refer to Fig. 1):
1. Wrap two rubber bands around the recorder on either side of the top-most finger hole.
2. Trap the large clip of the GLM-UM Universal Mount (included with the microphone) under the rubber bands. Place the large clip on the right side of the recorder (player’s perspective).
3. Bend the mount-wire 90 degrees so that the small clip is above the center of the finger holes.
4. Clip onto the GLM flex relief; aim the front of the mic at the recorder.
5. Route the GLM cable down the GLM-UM mount and through the large clip.
The following placement provides the most gain before feedback with a sound-reinforcement system.
The tone quality is slightly less natural, but the pickup of each note in the scale is uniform:
1 .Wrap a rubber band around the recorder next to the rectangular slot by the mouthpiece, on the
player’s side of the slot.
2. Trap the GLM-100 under the rubber band and aim the GLM at the slot. Be sure that the GLM is on
the player’s side of the slot so the GLM is not blown on.
When recording a soloist or group, do the recording in a hall with suitable acoustics - warm ambience
or reverberation. Place two GLM—100s 3 feet apart, recorder height about 3 to 10 feet from the
instrument(s) to pick up room ambience. Alternatively, place two PZMs on the floor about 3 to 10 feet
from the instrument(s), 3 to 6 feet apart.
These suggestions should work well to preserve the beauty of the instrument’s timbre.
GLM BANJO MIKING
The following techniques have worked well for miking a banjo with a Crown GLM-100:
1. For the most natural sound, clip the supplied GLM-UM Universal Mount to a banjo tension rod, and
clip the other end of the mount to the GLM strain relief. Place the microphone about 1 to 2 inches in
from the rim, 1 inch over the drum head, as in Figure 2.
2. For more isolation and more gain-before-feedback, tape the GLM directly to the drum head as
follows: Put some double-sided tape on the GLM on the side marked FRONT (as in Fig. 3). Tape the
GLM to the banjo head about 1 to 2 inches in from the rim, with the FRONT of the GLM aiming at the
head. Tape the GLM to the head with masking tape or drafting tape, taking care not to cover the
sound-entry hole (as in Fig. 2).
Fig. 2. Miking a banjo with a GLM-100.
Fig. 3. Use double-sided foam tape to mount a GLM on a banjo head. Also use masking tape (do not cover
sound-entry holes).
GLM KICK-DRUM MOUNTING
A handy way to mike a kick drum with a GLM-100 is to feed the mic and its cable through the vent
hole in the top of the drum and hang the mic in front of the beater.
If the vent hole on your kick drum is too small for the GLM to fit through, try this:
Hang the GLM by its cable inside the kick drum so it is the same height as the beater. Bend the cable
into a “V” near the vent hole, and insert the point of the “V” through the hole. Tie a knot in the cable
just outside the vent hole to keep the cable from falling through.
The GLM can aim in any direction since it is perfectly omnidirectional at low fequencies.
You’ll probably want to damp the beater head with a blanket to tighten the beat. Lay a blanket inside
the drum pressing against the beater head. Boost the treble on your mixer (ideally, several dB around
2.5 kHz) to increase attack.
UNDERSTANDING MICROPHONE SENSITIVITY
A microphone-sensitivity spec tells how much output (in volts) a microphone produces for a certain
input (in SPL). A high-sensitivity microphone puts out a stronger signal (higher voltage) than a lowsensitivity microphone when both are exposed to the same sound pressure level.
Microphone sensitivity is specified in several ways:
dBV per microbar
Millivolts per pascal
dBm per 10 dynes/cm2
dBm, EIA rating
We’ll explain each of these. First note that
10 dynes/cm2 = 10 microbars 1 pascal = 94dBSPL
1 dyne/cm2 = 1 microbar = 74 dB SPL
An example of a microphone sensitivity specification is:
Open-circuit voltage -60dB re 1 volt per microbar. That means the mic produces -60 dBV unloaded,
when exposed to a sound pressure level of 1 microbar (74 dB SPL). You put 74 dB SPL in; you get 60 dBV out.
A typical sensitivity spec is -65 dBV/ microbar for a condenser microphone and -75 dBV/microbar fbr a
dynamic microphone. Another way to express the same sensitivity is: Open-circuit voltage 10 millivolts
per pascal. That is, the mic produces 10 millivolts, unloaded, when exposed to a sound pressure level
of 1 pascal (94 dB SPL). You put 94 dB SPL in; you get 10 millivolts out.
Here’s still another less common way to specify the same sensitivity: Power level -38 dBm per 10
dynes/cm2. In other words, the mic produces -38 dBm into a matched load, when exposed to an SPL
of 10 dynes/cm2 (94 dB SPL). “Matched load” means that the load impedance equals the microphone
impedance. If the mic impedance is 150 ohms, the load impedance of the mic preamp input is also
150 ohms. This is unlikely to occur in practice; usually the load impedance is at least 7 to 10 times the
mic impedance.
The EIA rating or Gm rating is useful for calculating the microphone output into a matched load for a
given SPL. SPL + dB (Gm) = dBm output into a matched load.
To compare the sensitivities of two microphones specified in different ways, convert them to the same
reference using these formulas:
Millivolts per pascal = 10(4+dBV/2O) dBV/microbar = 20 log (mV per pascal/1000) -20dB dBm/10 dynes/
cm2 = dBV/microbar + 22.2 dB (if mic impedance equals 150 ohms) dB (Gm) = dBm/10 dynes/cm2 94dB.
If you put a microphone in a 20 dB louder sound field, it produces 20 dB more signal voltage. For
example, if 74 dB SPL in gives you -75 dBV out, then 94 dB SPL in gives you -55 dBV out. 150 dB
SPL in gives you +1 dBV out, which is approximately line level! That’s why you need so much input
padding when you record a kick drum or other loud sources.
###
MIC MEMO
October 1986
Bruce Bartlett, Editor
NOVEL CONFERENCE MIKING WITH PZM-20RMGs [now PZM-20R]
PZM-20R
Dave Haneman, the owner/engineer of Advance Video, is an audio/video systems consultant and
contractor. He devised an effective and invisible method of miking conferences with PZM-2ORMG
microphones.
The conference-room installation was done for Schlesinger Associates, a market research company in
Edison, New Jersey. Two PZM-2ORMG mics pick up the conversations of “focus groups,” in which
members of the public are interviewed about products. The focus-group rooms have one-way mirrors
for viewing and video taping.
The two microphones are mounted in upper opposite corners of the 18' x 25' conference rooms. The
rooms seat about 15 people around their tables. Reverberation is well-controlled because the floor is
heavily carpeted; the walls are painted drywall, and the ceiling is fiberboard tile. Each 2ORMG is
screwed into drywall, with the plate extending about 1" in from the wall and ceiling. Aluminum studding
in the walls prevent flush-mounting of the microphones.
Dave reports that results are excellent:
“Most of the group leaders are pleased or impressed with the sound. Intelligibility is very good, yet the
microphones are invisible so that interviewees are less self-conscious.”
Theory explains why this method works so well: Mounting the PZM element in a corner boosts its
acoustic sensitivity 18 dB (6 dB per boundary). That is, direct sound is boosted 18 dB, while reverberant sound, being incoherent is boosted only 9 dB. Thus there is a 9-dB increase in direct-to-reverb
ratio due to corner mounting. This makes voices sound closer and clearer than you’d expect with such
distant miking.
In testing the microphone set-up, Dave walked around the conference room counting his steps as he
went. Listening to the playback, he heard no indication that he was moving - no dead spots or hot
spots.
Through a Rane splitter/mixer, the mics feed two stereo audio recorders and a video recorder Some
clients want video recorded on 1/2" tape, but all 1/2" units have AGC, which raises the ambient noise
level during pauses. This has not been a serious problem, according to Dave. Air conditioning noise
around 1 kHz is partially filtered out with a Rane RE-14 equalizer. All equipment is rack mounted.
Due to budget considerations, no limiter is in the system, so the tape overloads slightly during loud
laughter.
Audio and video signals can be patched to various locations throughout the facility, such as a client
lounge. Most people listen to copies of the recorded conference over dictation machines.
A final note: Since the focus-group interviewees see no microphones in use, they must be reminded
that they are being recorded!
HANGING GLMs
Crown’s Don Peterson came up with this nifty way of aiming GLM microphones that are hung from the
ceiling:
Cut a 2" piece of coat-hanger wire. Tape or heatshrink it to the GLM cable near the capsule. Bend the
wire to the desired angle.
To prevent rotation of the mic, string a length of fishing line between multiple hanging mics.
For clear pickup of a video teleconference, hang a GLM-200 hypercardioid 5 feet over the conference
table, aiming down. The microphone hangs out of camera range, and so is invisible. It picks up only 1
dB more reverberation than a PZM in the center of the table.
UPRIGHT PIANO MIKING WITH GLMs
As an experiment, Mic Memo editor Bruce Bartlett miked a spinet piano with a spaced pair of GLM100 microphones in various positions. The back of the piano was facing a wall in a large carpeted
living room. The mics were always placed 1/3 in from the left and right sides of the piano. Here are the
techniques used and the resulting sound quality compared to the live instrument:
Upright piano miking with GLMs (see text).
Placement 1: Kick panel removed, mics hanging under keyboard 8" from the center of the exposed
soundboard (Fig. 1).
Results: Realistic, uncolored, sounds like it’s in the room with you. Full bass. Good imaging except for
bass notes. Stereo spread is from speaker to speaker. Sounds the most like a grand piano.
Placement 2: Over the open top, a few inches from the strings (Fig. 2).
Results: Colored, thin, constricted, slightly tubby. Good imaging.
Placement 3: On the wall behind the soundboard, PZM-style, soundboard 8" from the wall (Fig. 3).
Results: Mid-rangey. Poor imaging. High SPL, very good isolation.
Placement 4: On the wall behind the soundboard, PZM-style, soundboard 1" from the wall (Fig. 4).
Results: Less colored than placement 3. Pretty good tonal balance, but not very bright. Poor imaging.
Very high SPL, low leakage, very good isolation.
Placement 5: Kick panel removed. Mics taped PZM-style to the underside of the keyboard, about 8"
from the soundboard (Fig. 5).
Results: Less bass than placement 1, somewhat mid-rangey and constricted.
Placement 6: Kick panel removed, 3" from the soundboard (Fig 6.).
Results: Slightly harsh, woody, or “electric:’ Too close.
Placement 7: Kick panel removed, PZM-style on floor about 1 foot from soundboard (Fig. 7).
Results: Natural, fairly similar to placement 1. Slightly more ambient pickup.
PCCs and PZMs SOLVE COUNCIL INTELLIGIBILITY PROBLEM
Vince Taylor, chief engineer of Taylor-Maid Industries (a Palm Desert sound contracting/consulting
firm), supplied the following report and photos through Norm Marshank:
The problem:
Palm Desert’s City Council Chamber is constructed in the round. The interior is all cement and stone including the 24-ft.-high dome ceiling. In the center of the chamber, which houses the public seating
area, the “trash canning” effect is horrendous. Twelve “gooseneck’ mounted E.V RE-11 microphones
cluttered the chamber-members’ 35-ft. long table, the 6 ft. x 7 ft. support-staff table, and the public
podium.
Communication was minimal at best as the city fathers either did not talk into the microphones at all which provided minimal communication between the members and none to the public - or they overvocalized into the microphones, “ping-ponging” sound around the chamber to the point of total unintelligibility.
Two column speakers directed toward the public with no speakers directed toward the chamber members added to the impossible situation.
Taylor-Maid Industries was called in to resolve the problem.
The solution:
Three BES-C-12BT-70 hemispherically radiating speakers were ceiling mounted over the council
rostrum.
Six Crown PCC-160 microphones, one per council member, were mounted on the chamber desk at a
45-degree angle to the center line of the voice and at 2 or 10 o’clock, depending on availability of desk
space.
The PCC-160’s were placed to the side and angled, after a test showed the members using the microphones, placed directly in front of them, as a paper support for the reams of paperwork sifted through
at each meeting. Small TV monitors permanently mounted between every two members further increased the difficulty of “ideal” microphone placement.
Fig. 8. View from the council members’ desk showing PCC-160s.
One PCC-16O mounted on the top shelf of the public lectern solved all the previous problems of
communication between the council members and the public. The individual addressing the council no
longer has to be constantly admonished to “please speak into the microphone.”
Due to the outstanding characteristics of the PCC-16O, gain relative to feedback is excellent. Intelligibility and clarity are nothing short of miraculous, as council members consistently talk off-axis and rock
back and forth in their chairs.
One PZM-6FS [now PZM-6D] centered on the support members’ table very adequately covers all
seated members, usually six, with excellent intelligibility. Once the PZM-6FS has proven itself through
several council meetings it will be replaced with a PZM-20RMG.
From the mayor to the attending public, all are delighted.
We are so delighted, three PCC-160’s and four PZM’s have been spec’d into a local church installation.
RECORDING A ROCK CONCERT WITH TWO MICROPHONES
What happens if you record a rock concert with a classical miking technique - two microphones out
front? You get a realistic, “live”-sounding audience perspective of the concert.
It’s not the tight, polished sound you hear on records, but rather a “you are there” experience. With
this kind of recording, the band can hear how they sound to the audience.
When only two mics are used for overall pickup of an ensemble, the balance between instruments
and vocals is controlled by microphone positioning. The vocals (coming through the PA speakers) can
be made louder or softer relative to the instruments by moving the mics toward or away from the PA
speakers.
I recorded a rock band with two GLM-100 mini omni condenser microphones placed several feet in
front of the band, much as you would record an orchestra. The band was set up in a reverberant log
cabin to play for a dance. Figure 9 shows the arrangement.
Fig. 9. Setup for experimental two-mic recording of a rock band.
I hung the GLMs just above the reach of the audience. The location of the cabin cross-beams determined the position of the mics, which ended up farther from the band than desired. I should have
brought some mic stands to be able to mike closer. Also, once the mics were hung, they couldn’t be
moved during the concert.
The reproduced sound was wide-range with powerful bass and crisp cymbals. It also was very clean
(free of noise and distortion), with clear cymbal transient response. Compared to a record, the sound
was distant and the bass was muddy because of the distant miking. It had an audience perspective.
There was plenty of audience reaction (almost too much), which added to the “live” feeling.
I also tried a pair of PCC®-160 supercardioid boundary microphones, close together and angled apart
110 degrees. When these microphones were placed on the floor they were too far below the PA.
horns to pick up the high frequencies. So I placed the mics on a box near the front edge of the stage.
The resulting perspective was much closer and clearer than with the distant GLMs.
The PCCs were only about 10 feet from loud stage amplifiers, drums, and PA. speakers. Again, the
sound had a wide frequency range, with sharp cymbal transients.
Since people were dancing in front of the band, the PCCs could not be placed far enough from the
band to pick up a good balance. The keyboards were too quiet. So I used the more-distant GLMs for
the rest of the performance.
Doing this recording reminded me of several important tips for on-location jobs:
1. If possible, check out the recording site in advance so you can prepare for unusual circumstances.
2. Check all equipment and cables for reliable operation before packing.
3. Don’t wrap a 50-foot mic extension cable around your arm to coil it. The resulting coil is likely to
tangle. Instead, wrap the cable around a spool or small cardboard box. When you’re ready to use the
cable, it will unwind kink-free from the spool.
4. In planning the system set-up, draw a block diagram and use it to generate an equipment list.
Check off each piece of equipment on the list as you pack.
5. Bring a step ladder, power extension cord with multiple outlets, gaffer’s tape, a flashlight, a tool kit
and spare headphones.
6. Allow plenty of time for setup and last-minute repairs!
LETTERS FROM PZM USERS
Extending the GLM-200 cable
I want to hang some GLM-200’s over a choir but the interface is 8 feet from the mic and becomes
visible in a hanging situation. I want to extend the cable. How long a cable can be used between a
GLM mic capsule and its interface?
Steve Mills Elkhart, Indiana
Reply:
Twenty-five feet maximum is recommended. Here’s how we got that figure:
The impedance of the GLM capsule is 3000 ohms, which is mostly resistive. The capicitance of a 25foot cable of 40 pF/ft is 1000 pF. These two components form an RC lowpass filter. Let’s use the
formula for the frequency response of an RC lowpass filter:
dB = -10 log(1 +(2piFRC)2) where pi is 3.14, F is frequency in Hz, R is resistance in ohms, and C is
capacitance in farads.
At 20 kHz, the response of this filter is down 0.6dB. So, if you want to avoid further rolloff, don’t exceed 23 feet of cable length (assuming your cable capacitance is 40 pF/ft between conductor and
shield).
Belden 8451 is a thin (.135" O.D), foil-shielded mic cable suitable for hanging mics. Its capacitance is
67 pF/ft. With 25 feet of this cable, the response should be down 1.5 dB at 20 kHz.
Also, the cable attached to the mic capsule is a medium-impedance line, which is more susceptible to
hum pickup than a low-impedance line, so the cable length should be kept relatively short.
PZM stage miking
A drama instructor from a local high school comes to you with a problem. The only way that his students can be heard in the auditorium is to drag a hard-wired dynamic mic around with them everywhere they go. He is “TIRED OF IT!” The school board will not spend the money for five-to-eight
wireless lavalier systems, and he wants to know what you can do.
Well, if you’ve never seen a high school teacher grin from ear to ear try this: Sell them four PZM-180’s
[now PZM-185’s] mounted on plexiglass. Hang them out of sight above the stage (approx. 12 feet)
and position them as shown (Fig. 4). Add to this three dynamic cardioid mics (which they may already
own) positioned across the proscenium lip. Your breath can almost be heard from any position on the
stage.
Fig. 10. PZMs on plexiglass boundary.
These mics were installed along with an entirely new sound system from mixer to cluster for under
$7000. Believe me when I tell you, a friend was made.
Best wishes,
Micah L. Collins, Dyna-Might Sound & Lighting, SPFD., MO
###
MIC MEMO
January 1987
Bruce Bartlett, Editor
NEW PZM ARRAY PROVIDES OUTSTANDING AUDIO FOR STEREO TV
GHOSTBUSTERS! GTN Soundmixer Gary Pillon stands ready to capture sound.
Gary Pillon does it again! A sound-mixer for General Television Network of Detroit, Gary devised a
stereo PZM and used it to record exciting stereo sound tracks for video documentaries.
He used two Crown PZM-6S [now PZM-6D] microphones mounted in PZM-2.5 boundaries [discontinued], designed as a single-device stereo shotgun. The mics are 8" apart in an ORTF stereo arrangement, so that the stereo effect works equally well over headphones or loudspeakers. Shown below,
the boundaries provide 18 dB of acoustic gain.
Fig. 1. Pillon’s PZM Stereo Shotgun mic.
Gary describes several applications of this unique microphone.
This Fall has been one of the busiest GTN has ever had. Our success has been due in no small part
to the use of the PZM Stereo Shotgun. Let me give you a chronology of its application this year, and
some of the things we have learned about it.
When I built a large and a small PZM shotgun last December, I hoped to use them as stereo spot
mics along with my overhead wedge array for music recording. The PZM Shotguns really lived up to
their name, giving a close-up perspective that was too tight to match the openness of the overall
sound field.
I therefore decided to get them into TV productions, and test them in places where a mono shotgun
would have been the logical choice.
WDIV-TV Channel 4, the Post-Newsweek station in Detroit, took an early interest in their potential. On
April 27th, the station used the large model as the main stereo crowd mic for a Detroit Tigers ball
game. They were so happy with the results that they booked both models to cover the launch and
detonation areas of the Detroit Freedom Festival Fireworks display on the Detroit River.
However, they had less luck indoors. They tried to use them in their studio while running air conditioning.
Unfortunately, the PZM’s blessing is also its curse: the devices heard too much unwanted sound. The
low-frequency noise due to the omnidirectional pickup at low frequencies could not be corrected
without much equalization. Therefore, conventional mono shotguns were used to reduce sound from
the lights and air onditioning.
Another job proved the true merit of the device and its flexibility for TV: a half-hour stereo documentary on the Michigan Muzzleloaders Festival. This three-day conclave occurs every June at Greenfield
Village, Michigan. People from around the country come to reenact the past in period costumes,
lifestyle, and a black powder shooting contest. The Sound Moves production company wanted us to
get as real a feeling as possible, with a natural, “sense of place” viewpoint.
GTN contacted Kirk Gardner, a local Steadicam owner/operator, to shoot the event with one of our
Sony Betacam Stereo Camera Recorders.
Burr Huntington, the Sound Moves audio man, recorded all his tracks onto a jammed-sync time-code
center-channel stereo Nagra. He matched an AKG CK8 short shotgun with a Beyer ribbon bidirectional, giving him a Mid-Side shotgun that had tremendous reach, while enabling him to match ambience to picture during post production.
I wanted to replace the camera’s mono shotgun with a stereo ambience mic that would make the
visual image as real as possible. To do this, I created two new stereo devices called PZM Stereo
Shotguns. I placed two Crown PZM-6S [now PZM-6D] cantilevers into each specially constructed
Lexan array. Two microphones of each array are spaced 8" apart to mimic human hearing, yet reproduce a very convincing sense of three-dimensional space from two loudspeakers.
My job was to supply stereo audio to the Betacam. I used one of the mics on a television “C” stand,
which gave ten-foot-high overviews of the weekend’s events. Parades, marching bands, and the
gunfire of 80 contestants at a time envelop the listener, even at low levels on inexpensive speakers.
This mic also had a pistol grip for handheld use.
The smaller version of the shotgun was mounted as described in the Boundary Booklet, under the
lens of a Steadicam, feeding its preamps directly.
The audio perspective was a perfect match to the field of view given by the wide-angle setting of the
Sony Betacam zoom lens. While the mic picked up sound from all over Greenfield Village, the central
sonic image always matched the picture.
Parade coverage, field events, and the chase after a six-horse gun carriage gave spectacular proof of
the value of stereo television. This setup was an outstanding success. Its uncanny knack for matching
visual perspective is unrivaled by any other technique. So far as we know, this was the first time that
such a recording has ever been done from the Steadicam platform - a world first for the PZM Shotgun.
It opened entirely new areas of audio recording.
f
PZM stereo shotgun mounted on Steadicam platform.
Dialogue was locked in the center of the image, while a whole sound space was created around it.
This effect also worked well when the camera was on sticks, or hand held, as long as Kirk and I
worked to get the audio and video to match.
The hand mic also worked very well, and direct comparisons of Mid-Side and PZM were often made.
In these cases, we had the added advantage of being able to use the shotgun Mid from the Nagra
tracks and match it with the ambience tracks from the PZM Shotgun. As a result, the dry voice-over
narrator sounded perfectly at home in the new stereo ambience.
The handheld device also worked well on dialogue. Its subjective reach was as great as a shotgun,
and could be augmented by panning the image towards the center without losing a stereo feel. It’s
important to aim the mic properly in the first place.
In September another documentary created the first commercial use of the Stereo Shotgun as the
primary source for stereo audio. Philip Handleman of Handleman Filmworks commissioned GTN to
tape the Annual Stearman Fly In, held each September in Galesburg, Illinois. This year, 91 Stearman
biplanes, the old WWII training planes, were scheduled to spend a week at the Galesburg Airport. Phil
had heard pieces of the Muzzleloaders tracks, and wanted to shoot the whole project, from interviews
to ambience, in perspective stereo.
A Vega wireless for his off-camera questions was mixed with the small shotgun through a Shure FP32
mixer; The output was fed to a Sony Betacam. As you can hear from the tape, the results are outstanding. Dialogue can be understood over heavy background noises, and the flying pass-bys are so
realistic that you can feel planes going by in three dimensions, even on a stereo pair of inexpensive
loudspeakers.
From these stories, I can draw several conclusions:
*The devices work very well if they are properly placed for good standard microphone techniques.
*They blend well with other microphones if you are dissolving between ambience situations. They do
not blend well as stereo spot mics, because of their distinct perspective.
*Room conditions may make their use inappropriate.
In short, I believe very strongly that the PZM Stereo Shotgun has a definite future in the field of location recording.
PCCs SOLVE STAGE PICKUP PROBLEM
Nico Valentijn, media specialist for Central High School in Elkhart, Indiana, started using two PCC160’s for stage-floor pickup of drama. They replaced three EV RE-15’s in mice.
According to Nico, the PCCs “worked quite well.” In fact, the first time they were tried, the sound was
so much louder and clearer that he yelled to others to come listen to the sound. Nico also reports that
the coverage was much better, and the “bottom of the barrel” effect was reduced.
The two PCCs were the main floor mics for sound reinforcement. Another PCC was center stage to
feed a VCR and the dressing room. A fourth unit was upstage on a second level.
In past years, the orchestra was too loud. The RE-15’s picked up the orchestra, but the PCCs did not
as much, so their gain could be brought up. But since the speech was louder, the orchestra started to
play louder too! They were asked to play at a normal level.
LETTERS FROM PZM USERS
PZM Stage Miking
I used PZM-6RB [now PZM-6D] mics in a theatre on stage. They were placed on a pole 18-1/2 feet
over the stage for monitoring in the cabin. Now we have sound in the cabin in Theatre Yaguez.
Thank you for this Crown microphone. It’s number one on stage.
Sound Technician, Theatre Yaguez, Mayaguez, Puerto Rico
Fig. 2. Stage layout of Theatre Yaguez (drawing by Theatre Yaguez sound technician).
PZM sports pickup, PCC on newscaster
I am involved in a lot of remote television broadcasting, mainly sports. I purchased a pair of PZM mics
last summer, and thought I would pass along some of my experience with them.
When the Toronto Blue Jays telecasts went stereo this year, I used the PZMs in a near-coincident
arrangement for stereo crowd pickup. I was impressed at how natural the sound was. It almost
seemed that you were in the crowd.
I have also used them to good effect on a hockey broadcast. I taped them high onto the glass behind
the nets. The skate and board sounds were great but the placement is a bit risky.
When the female talent on our local newscasts decided that they wouldn’t wear lavaliers anymore, we
experimented with a number of desk mics. We eventually tried and stuck with a PCC-160. The sound
quality is best described as “boom like” (the reverberation pickup is similar to that of a boom-mounted
shotgun mic). However, we found it to be a little lacking in the bottom end. (Try the “boost” position on
the PCC’s bass-tilt switch - Ed.)
Paul Patenaude
Toronto, Ontario
###
MIC MEMO
April, 1987
Bruce Bartlett, Editor
PCCs PICK UP BOY’S CHOIR
This application note is from Lance Abair of Paragon Music Center, Florida. At the Florida All-State
Music Educator Clinic, a boy’s choir was accompanied by a piano. Two PCC-160’s were placed on top
of the piano as shown in Fig. 1. According to Lance, the piano sounded excellent, and there was a
very good balance between piano, choir, and soloist.
Fig. 1. Miking a boy’s choir with two PCC-160s.
RIGOLETTO RECORDED WITH CROWN MICS
Mike Lamm, of Dove & Note Recording in Houston, recorded the Rigoletto opera using Crown microphones exclusively, with great success.
A PZM ‘axe” or “wedge” was the primary pickup. An axe consists of two 2-foot-square boundaries
joined along one edge to form a “V’ The point of the V aims at the sound source.
Four PCC-160s on stage were mixed in to add presence on the singers. In all, six mics were used.
According to Mike, “my totally biased opinion is that the tape sounds great!” We agreed. The recording Mike sent us sounded smooth and natural, with just the right amount of ambience, a fine balance
between the singers and the orchestra, and very good imaging.
REINFORCING TRADITIONAL INSTRUMENTS WITH GLMs
At a recent concert in a coffee house, GLMs were used to reinforce and record a wide variety of
acoustic stringed instruments. Dan and Jenny Gellert - an oldtime-music duo who are outstanding in
their field - taped or clipped GLM-l00s to all their instruments: guitar, banjo, fiddle, dulcimer, and
bouzouki.
I did sound reinforcement and live recording for the concert, and had a chance to judge the effectiveness of the GLMs on these acoustic instruments. Figure 2 shows the setup.
Fig. 2. Stage setup.
Loudspeakers were home bookshelf types, EPI-100s. Although they had to be placed close to the
performers, we never ran into feedback. This is partly because traditional acoustic music does not
require a high stage volume. Also, I turned down all mics not in use, which is standard practice to
reduce potential feedback.
Microphone placement was as follows:
Acoustic guitar: Halfway between the sound hole and the bridge, near the low B string, taped to the
guitar PZM-style. This means, the GLM is mounted on the guitar surface, spaced .032" by the included foam spacer, with the FRONT of the mic aiming at the surface.
Dulcimer: Near one of the sound holes, PZM-style. See Fig. 3
Fig. 3. Dulcimer miking with a GLM.
Bouzouki: Near the sound hole, PZM-style. According to Jenny, a bouzouki is “a mandolin with a
hormone problem!” See Fig. 4.
Fig. 4. Bouzouki miking with a GLM.
Banjo: Halfway between the first string and the rim, 1 inch above the head, held by a GLM-UM Universal Mount clipped to the tailpiece.
Fiddle: About 1 inch above an f-hole, held by a GLM-UM Universal Mount clipped to the tailpiece.
I noticed that the GLMs required little or no equalization when mounted in these positions. They accurately reproduced the delicacy of the instruments’ timbres; there was no harsh, electronic sound.
NOTE: When taping a GLM to an instrument PZM-style, it’s important to keep a constant spacing
between the mic and instrument. Don’t let the mic pull away from the surface; otherwise, you’ll lose
high-frequency response. The Gellerts also recommend taping down the cable a few inches from the
mic capsule, allowing some slack between capsule and tape to serve as a strain relief.
As a side note, the power amplifiers in my powered mixer failed fifteen minutes before show time.
Fortunately, the previous band had left their powered mixer on stage. I borrowed it, then quickly soldered together a patch cord to connect my mixer output to the band’s powered mixer It saved the day.
Just goes to show: One life-saving experience with a product can greatly increase your respect for it,
and one bad experience with another product can devalue your opinion of it.
Jenny emphasizes that “We love using GLMs because not only do they allow freedom of movement
on stage, but more important to us, they give the warmest, most natural reproduction of folk instruments. Part of the joy of this music is the unique blend of our vintage Martin guitar with a turn-of-thecentury banjo or handmade fiddle. GLMs faithfully capture these musical subtleties.”
GLM-100 FLUTE MIKING EXPERIMENTS
Where is a good place to put a GLM-100 on a flute for recording or sound reinforcement? We tried the
following experiment to find out:
For a natural-sounding reference, a GLM-100 was placed 2 1/2 feet in front of, and above, a flute.
This mic was plugged into channel 1 of a stereo recorder. Another GLM-100 was mounted on the flute
in various positions. The mic was plugged into channel 2 of the recorder. During playback, we
switched between the two channels and compared the tonal balance. The results are shown in Fig. 5.
Fig. 5. Tonal effects of various GLM placements on a flute.
The embouchure hole is the loudest part of the flute, so the closer the mic is to the lips, the better the
gain-before-feedback. Also, the closer the mic is to the lips, the breathier is the tone. You can reduce
breath noise by aiming the mic away from the lips, toward the flutist’s right shoulder. Mechanical noise
is minimized by keeping the mic capsule away from the body of the flute (say, by taping the cable to
the flute, with the mic capsule an inch or two above the flute).
The following positions gave these results:
On the player’s right ear: dull, no breath noise, poor gain-before-feedback.
On the player’s wristwatch: same as above.
On the player’s lapel near the neck: same as above.
2 inches in front of the lip plate: good gain-before-feedback, breathy, and bright.
In general, no windscreen was needed except for outdoor use.
A good starting position for close-up recording is about 4 inches to the left of the lip plate (looking at
the flutist), 1-2 inches above the flute. This position gives a natural sound with very little mechanical
vibration pickup. A good spot for sound-reinforcement is at the end of the flute near the lip plate (at
the crown), with the mic capsule one inch over the flute, and with some treble rolloff at the mixer to
restore a natural tonal balance.
GLM-100s USED TO DEMONSTRATE FLUTES
When a flute is played, hard blowing causes a shrill tone quality, loses intonation and reduces dynamics. Softer blowing is better, but then the flute has low volume or poor projection. Fortunately, projection can be increased by careful design of the flute’s headjoint, which is the short cylinder containing
the lip plate.
Flutemaker David Wimberly makes special head joints that have excellent projection to a concert-hall
audience. His problem: How can he demonstrate this projection to a flute player? While two different
head joints may sound equally loud to the player, they may project very differently to an audience.
How can he demonstrate audience projection to a flutist, who can’t hear what the audience hears? His
solution is to make a special recording with GLMs.
As shown in Fig. 6, David mounts one GLM-100 very close to the flute to pick it up as the player hears
it. He places another GLM in the audience area of an auditorium. The close mic is recorded on channel 1 of a 2-track recorder; the audience mic is recorded on channel 2. So, he records the flute simultaneously with a close mic and a distant mic.
Fig. 6. Close/distant comparison of flute.
This recording is done with the flutist using a competitor’s head joint. Then, without touching the
record levels, the recording is repeated with the flutist using David’s head joint.
While listening to the playback over mono headphones, the flutist switches between channels 1 and 2
to compare the close sound to the distant sound. This is done both for the competitor’s head joint and
David’s head joint. As the recording demonstrates, the two head joints may sound equally loud to the
player, but in the audience, David’s head joint gives louder projection.
David says that the GLM-100 provides high-fidelity reproduction of the flute’s timbre, and is easily
portable for on-location demos.
SUPERBOWL PZM
At the January Superbowl, a PZM-6LP was used on the turf to pick up the coin toss at the beginning
of the game.
GLM CIRCUIT FOR ACOUSTIC GUITAR
Figure 7 shows a simple circuit you can use with a GLM-100/E to pick up a guitar for sound reinforcement. The 100/E is medium impedance, so your cable to the mixer should be under 20 feet long. Use
a 0.22 microfarad capackor or greater for more bass; use a 0.1 microfarad capacitor for less bass.
Little or no equalization should be needed.
Fig. 7. GLM circuit for acoustic guitar.
Tape the GLM cable to the pick guard, so that the mic is flush with the sound hole near the bottom.
The result is a natural-sounding pickup with good gain-before-feedback, and for less than $99.00.
MICROPHONE COMBINING CIRCUIT
Suppose you want to hang two mics over a choir for sound reinforcement, but you don’t have enough
inputs on your mixer. Here’s a simple circuit (Fig. 8) that combines the outputs of two microphones
into one without loading down the mics:
Fig. 8. Microphone combining circuit.
LETTERS FROM PZM USERS
Theater miking
I am a sound technician of the company Theater Yaguez De Mayaguez, Puerto Rico. In exploring your
literature and the Mic Memos, I haven’t found any in-depth coverage of PZM use in a live setup like
mine.
I perform living-theater production on stage for my cabin work. My setup includes PZMs 25 feet high
off-stage for live recording on stage, which pick up every instrument on stage, like the last concert of
Spader Yadia jazz. It seems that a major problem with PZMs in a situation like this is the excessive
pickup of ambience (reverberation). It is up to you on your setup.
I love your PZM product.
Jaime Ruiz Placido, Theatre Yaguez, Mayaguez, Puerto Rico
Reply:
To reduce ambience pickup, place your PZMs closer to the musicians. For starters, try a placement 10
feet in front of the front-row musicians, and 10 to 14 feet above the stage floor as shown in Fig. 9.
Fig. 9. Stage miking with a PZM wedge.
Try a PZM wedge, which is made of two 2-foot-square panels joined along one edge to form a “V”.
Mount a PZM on each panel so that the mics are about 8 inches apart.
You may want to mix in several closeup “spot” microphones on drums and instrumental sections for
extra presence.
PCC stage miking
This setup (Fig. 10) gave an incredibly natural pickup of the stage without picking up too much orchestra (obviously because of the supercardioid pickup pattern). Also, there was plenty of gain before
feedback.
Mark Bunce
College of Music Recording Services
Bowling Green State University
Bowling Green, Ohio
Fig. 10. PCC stage miking.
PZM stage miking
We use two PZM-6LPG’s [now PZM-6D’s] on 2-foot plexiglass panels for plays and assemblies. With
young (short) people, I usually mount the mics as shown (in Fig. 11 below). Is this the best way?
Martin Guttenplan, Drama Dept. head
Maclay School
Tallahassee, Florida
Fig. 11. A PZM stage miking method.
Reply:
The way you showed is good, Martin especially if the pit orchestra is on the back side of the panel.
Here’s another way that (1) makes the mics more directionaL (2) makes them reject sound behind
them, and (3) increases their sensitivity:
Mount the mics in the junction of the stage floor and a vertical 1-foot plexiglass panel, as shown in
Fig. 12. The large plex panel disappears at a distance.
Fig. 12. Making PZM directional with boundaries.
Better yet, try two or three Crown PCC-160 microphones spaced across the front edge of the stage,
on the stage floor. These supercardiod boundary microphones have very good rear rejection and
excellent gain-before-feedback.
###
MIC MEMO
June, 1987
Bruce Bartlett, Editor
CROWN REVEALS THREE INNOVATIVE HAND-HELD MICROPHONES
Three new hand-held microphones designed and built by Crown were shown at the June N.A.M.M.
show in Chicago. These are the CM-100 PZM hand-held omnidirectional [discontinued], the CM-200
cardioid [now the CM-200A], and the CM-300 Differoid [now the CM-310A]. All are electret-condenser
types. They provide studio-quality sound, yet are rugged enough to withstand hard professional use in
the field.
Their outstanding performance is complemented with handsome styling and a comfortable balance in
the performer’s hand. In each microphone, a built-in pop filter effectively suppresses explosive breath
sounds. Handling noise is extremely low The units can withstand repeated drops and abuse, as well
as extremely loud sound pressure levels without distortion. They are balanced, low impedance, which
allows long cable runs without hum pickup or high-frequency loss. Each microphone can be phantom
powered from the console or other remote power supply. Included with each microphone is a convenient carrying pouch, an adjustable microphone stand adapter for mounting the unit to any microphone
stand, and a foam windscreen for outdoor use or additional pop protection.
The Crown CM-100 [discontinued] is a hand-held omnidirectional condenser microphone for professional stage-vocal use where feedback is not a problem. Frequency range is wider than that of standard vocal microphones (20Hz-20kHz). The CM-100 has the desirable studio sound of the PZM-6R
[now the PZM-6D] in a more convenient package. Since it has no proximity effect, it provides a natu-
ral, articulate sound without equalization.
CM-100
The Crown CM-200 [now the CM-200A] is a cardioid condenser microphone for stage vocal/ instrumental use. The sound of the CM-200 is smooth and non-harsh - yet very articulate - with a wider
frequency range than standard vocal microphones (80Hz-15kHz). When used up-close, its proximity
effect boosts the bass for a warm, robust sound. An upper-midrange “presence peak” aids intelligibility. The cardioid polar pattern increases gain-before-feedback, rejects unwanted background noise
and leakage, and discriminates against sound approaching the rear of the microphone.
CM-200
The Crown CM-300 Differoid [now the CM-310A] is a close-talking, hand-held differential-type condenser microphone for professional stage-vocal use. Frequency response is 60Hz-18kHz - unheard of
for a differential microphone. The noise-canceling capsule provides exceptional gain-before-feedback.
It permits extremely loud monitor levels before feedback occurs. This is due to Crown’s new patented
methods of improving rear discrimination, far-field rejection, and high-frequency response. The CM300 also rejects unwanted background noise and leakage, and discriminates against distant sound
sources such as monitor loudspeakers or instruments.
CM-300
PZMs FEATURED PROMINENTLY IN REQUIEM BROADCAST
In a recent PBS broadcast of Verdi’s Requiem Mass in the Spectrum Arena of Philadelphia, four
Crown PZMs on plexiglass boundaries were used to pick up the orchestra.
Conducted by Lorin Maazel, the Opera Company of Philadelphia chorus and orchestra accompanied
Luciano Pavarotti and the winners of the international voice competition. (This competition was
founded in 1980 by Pavarotti and the Opera Company of Philadelphia). John F. Pfieffer was Audio
Director for the show, and William King was Audio Supervisor.
As shown in Fig. 1, each PZM was mounted in the center of an octagonal plexiglass panel raised on a
mike stand. The panel appeared to be about 4 feet diameter and raised 12 feet high, aiming down at
the front row of the orchestra. In addition, there were spot mics on the orchestra, choir, and soloists.
The announcer for the broadcast said, “On stage we see the octagonal-shaped Pressure Zone Microphones which help provide a concert-hall-like sound.”
[Fig. 1. PZM placement at Requiem Mass.]
NOTRE DAME JAZZ FESTIVAL USES CROWN MICS EXCLUSIVELY
Once a year in April, big-band jazz groups from colleges around the country come to South Bend,
Indiana, to play at the Notre Dame Collegiate Jazz Festival - the oldest such festival in the country.
The musical talent displayed at this concert is remarkable.
In past years the event was competitive, but recently the contest aspect has been de-emphasized in
favor of promoting a festival feeling. Bands play in a relaxed, friendly atmosphere, while the judges
(most of whom are professional musicians) critique talent. Still, there is an “Outstanding Performance”
title awarded to the most deserving big bands and combos, as well as an “Outstanding Instrumentalist” certificate for individual performers.
Chicago nightclub owners scout the festival for talent, while judges sometimes recruit promising musicians for their groups.
Many participants have gone on to major success in the recording industry, such as David Sanhorn,
Bob James, Al Jarreau, and the Brecker brothers.
Friday evening during the festival, the judges get up on stage and jam, to general amazement. This
April the judges’ jam included Frank Wess, saxophone; Red Rodney, trumpet; Kenny Kirkland, piano;
Charlie Haden, bass; and Roy Haynes, drums. Judges in past years have included such stellar musicians as Winton and Bradford Marsalis, Lew Tabackin, Alan Dawson, Ron Carter, Tony Williams,
David Sanborn, Clark Terry, and John Lewis, to name a few.
Providing quality sound reinforcement for this important event is a major consideration. This year,
sound reinforcement was ably handled by Pro Audio, a company based in Grand Rapids, Michigan.
Richard Dekker, a house mixer and technician for Pro Audio, provided the following information on the
sound system.
All the microphones and amplifiers in use were made by Crown International. The house mixer was a
Soundcraft Series 800 B, and the loudspeakers were Pro Audio’s custom designs using components
made by JBL and Community Light & Sound.
Figure 2 shows the stage layout and microphone setup. Pro Audio used Crown GLM-200’s for many
of the instruments. The GLM-200 is a miniature hypercardioid condenser microphone. It was used on
the horn sections, drum overhead, snare drum, percussion, grand piano, electric guitar, and acoustic
bass. All GLMs were used as supplied from factory stock with a slightly rising high end. Monitor mixer
Tony Francisco reports that feedback was never a problem.
Fig. 2. Typical stage layout.
The GLMs were mounted in GLM-OHM boom arms [discontinued], which use 1/4" diameter black
rods. Since the booms are inconspicuous, the stage setup was clean and uncluttered.
A Crown PCC-160 supercardioid boundary microphone was used in the kick drum. Equalization was
typical for a kick drum: extreme cut around 400 Hz and boost around 2.5kHz. One drummer whacked
a GLM with a stick, but it kept on working.
Two mics were placed in the grand piano with the lid closed to reduce leakage. A PCC-160 was
mounted on a foam block on the soundboard, aiming at the treble strings, about 2 1/2 feet from the
hammers, The bass strings’ were covered by a GLM-200 aiming down at the sound board, attached
near a rib by a GLM-HM horn mount, also 2 1/2 feet from the hammers.
Dekker said he was impressed with the clarity of the piano reproduction. Even though the lid was
closed, the sound was not muddy. Piano solos cut through the instrumental backup.
The acoustic bass had an unusual miking arrangement. A GLM-200 was clipped to a GLM-HM horn
mount, and inserted into an f-hole, about 7" inside the cavity of the instrument. The other end of the
horn mount was clipped onto the f-hole. This GLM was mixed with a direct feed from a pickup on the
instrument. According to Dekker, this resulted in the best acoustic bass sound he has ever heard.
The new Crown CM-200 [now the CM-200A] cardioid condenser microphone was used for soloists,
virtually without equalization. Dekker said the microphone was “super,” “phenomenal,” with “a nice
high-end crispness and airiness:’ He said he was “really impressed,” and added that “even the judges
were talking about the microphones.” Dekker wants to try these mics for his home studio.
Solo trumpets and saxes were miked about 8" away with the CM-200.
Crown amplifiers included PSA-2 and Micro-Tech 600 LX units for the house systems, mounted in two
roll-around racks near each speaker cluster. The monitor system used Micro-Tech 12OOLX’s and D75’s.
To my ears, the overall sound quality at the festival was well-mixed, clear and bright, with a studio
“sheen.” We’re happy that Crown mics and amplifiers contributed to the enjoyment of the festival.
NOVEL GLM SETUP PROVIDES NATURAL RECORDING
’Twas an evenin’ of Irish music and poetry at Notre Dame University Library. There I recorded a hammer dulcimer, guitar, bouzouki, pipes, flutes, and bodhran drum with two GLM-100/E microphones on
a boundary. The results were delightful.
Figure 3 shows how the two GLMs were mounted. They were placed on a 2-foot-square plexiglass
boundary (Crown A240) [discontinued] as a spaced-pair array. The mics were only 14 inches apart,
yet provided excellent stereo. Each GLM was mounted facing the boundary, with a gap or spacing of
.032 inch.
Fig. 3. GLMs on boundary.
The boundary was placed on the carpeted floor, angled up to aim at the performers about 5 feet away.
I heard no comb filtering due to floor reflections. In general, the boundary/mic array was placed in the
center of the performers (Fig. 4). When only two musicians played, I placed the boundary between
them, out front.
Fig. 4. GLM placement near group.
An alternative stereo technique using a single boundary is to place the mics on either side of the
boundary, and aim the edge of the boundary at the performers. This provides a coincident-pair pickup.
In the Notre Dame recording, however, the boundary was facing the performers to provide forward
directionality. I didn’t want to pick up the PA. speakers at either end of the performing ensemble.
Each GLM-100/E was powered from a 9V battery, and ran unbalanced, medium impedance, through a
25-foot mic extension cable to a Sony Walkman Pro. I was impressed at the quality of the recording
obtained. No hum, hiss, or high-frequency loss was audible.
The overall sound was clear, natural, spacious, and wide-range, with good imaging. It was simply
realistic, giving a “you are there” feeling.
I recommend this setup and equipment to anyone wishing to make purist, true-stereo recordings of
small acoustic ensembles. Caution: floor monitor speakers near the microphones may degrade the
recordings, so try to position the mics to avoid picking up the monitors.
PCC-160 PAD
In some applications, PCC-160 supercardioid boundary mics are used along with PZMs. The PCC160 is about 13 dB more sensitive than current PZMs because the PCC is used mainly for distant
pickup on stage floors.
If you want to make the output levels of the two mics more equal, try the circuit shown in Fig. 5. It is a
13-dB pad to reduce the sensitivity of a PCC-160 to that of current PZMs. Plug the pad in-line with the
PCC’s output connector.
Fig. 5. PCC-160 13 dB pad.
USING A GLM OR A PZM ON A 2-FOOT DISK
If you mount a GLM on a 2-foot-diameter plexiglass disk, how does its response differ from that of a
PZM on the same disk? Figure 6 shows the results. Figure 6-A is the frequency response of a GLM100 mounted PZM-style in the center of a 2-foot diameter disk. Figure 6-B is the same with a PZM-6S
[now the PZM-6D]. The bump around 500 Hz and dip at 1kHz are due to sound waves generated at
the edge of the boundary interfering with incoming sound waves.
Note the improvement that occurs when the microphone is placed off-center (Figs. 6-C and 6-D). The
response is smoother because the distance from the mic to the disk edge is different in every direction. Consequently, phase interference from edge waves is less.
Fig. 6. Frequency response of GLM and PZM on 2-foot disk.
PZMs USED IN AIR SUPPLY CONCERT TOUR
In the recent tour of the pop group Air Supply, house mixer Steve Zelanka used a Crown PZM in the
kick drum. He mounted a PZM on a 12" x 10" x 1/2" plexiglass sheet, which was placed inside the
drum. The PZM output was gated, compressed, boosted around 8OHz-lOOHz with a Klark-Teknik
DN33 third-octave graphic equalizer, and finally went through a dbx model 500 Boom Box.
LETTERS FROM CROWN MICROPHONE USERS
Padding plexiglass boundaries
We use two PZMs on stage for sound reinforcement on high-school musicals. They fit in plexiglass
triangle units. Speakers hang behind them facing the audience, creating a slight ring when the gain is
pushed to the limit.
I found that by padding the plexiglass (as in Fig. 7), I could help the actors a bit more and eliminate
the ring.
Fig. 7. Padding a plexiglass pyramid.
###
MIC MEMO
December, 1987
Bruce Bartlett, Editor
MIKING THE ATLANTA SYMPHONY WITH GLM’S
“All the results are very, very good,” says Rex Garrett about reinforcing the Atlanta Symphony with
GLM microphones. Rex is with Showorks, a Crown dealer in Marietta, Georgia. He is the monitor
mixer and handles close miking of the symphony for concerts. Walt Wynn is the sound contractor,
house mixer and does overall miking.
They use Crown GLM-200 miniature hypercardioid microphones on violins and violas. Rex modified
the GLM electronics for flat response by changing the plug-in resistor according to Crown GLM Technical Bulletin no.1. For extra bass response, they use GLM-100 miniature omnidirectional microphones on cello and bass.
Overall boom miking is employed if the orchestra plays by itself. For pop concerts with orchestral
accompaniment, each instrument has its own microphone. Some recent pop concerts featured such
performers as Donna Sommers, Ray Charles, and Lou Rawls.
For violin miking, they tried clipping a GLM-UM Universal Mount to the tailpiece, but it is uncomfortable to the player to have anything in the way. They also tried clipping the GLM-TM Tie Mount onto
the bridge, but its weight mutes the instrument slightly. Currently they are experimenting with an elastic Velcro piece that wraps around the bridge and holds the tie-tac mount. Another idea is to clamp
onto the ribs of the violin — or the chin rest — and use a bar to hold the GLM over the sound board.
Cellos and bass are miked with a GLM-UM Universal Mount clipped to the tailpiece, holding the mic
near the bridge.
There are three trumpet players; each is picked up with a GLM-200 clipped to the top of a music
stand. To reduce low-frequency feedback, frequencies below 200 Hz are rolled off. “Hot Spots” are set
up close to the horn players’ heads for stage monitoring. According to Rex, the trumpet players are
“exceptionally happy’ with this setup.
For piano miking, they plan to use three GLM-200 mics as follows:
*One under the sound board
*One over the sound board near the bass strings
*One over the sound board, near the treble strings, near the keys.
*Alternatively, they will try a coincident-pair setup clipped to the bridge of the piano.
There’s a lot of cabling on stage, which makes quick changes between sets difficult. It helps if the
musicians take their mics with them when they go off-stage. Rex and Walt provide a microphone
junction box to accommodate every four players.
They are planning to try a 50-input passive mixer stationed off-stage. This mixer would include phantom power, cue buttons, and a mute button for each microphone. The mute buttons are necessary
because some string players occasionally move the bow over the microphone. The off-stage mixer
would combine the 50 inputs into 10 outputs to be sent to the house mixer.
According to Rex, the reinforced sound is very natural.
CROWN CM-200 MICROPHONES USED EXTENSIVELY IN SPECIAL
OLYMPICS
The Crown CM-200 cardioid condenser [now the CM-200a] was the microphone of choice for the
1987 International Summer Special Olympics Games. This was the world’s largest amateur sporting
event of 1987. It represented a world-wide effort to recognize the skills and courage of mentally handicapped athletes.
Participating in the event were 4,700 athletes from 72 countries, plus 12,000 volunteers, included
hundreds involved with the audio systems at the Games. Audio was supervised by Tom Durell, a
leading freelance audio engineer who was sound engineer for last summer’s Liberty Weekend and the
1984 Summer Olympics in Los Angeles.
Held at the campuses of Notre Dame and St. Mary’s college in South Bend, Indiana, the Special
Olympics ran from July 31 through August 8.
The Olympics required several elaborate sound systems because much of the program included
musical entertainment. In addition to the Opening Ceremonies, small concerts kept the spectators
occupied and entertained. In all, there were 314 sound setups used in 8 days!
The sound systems included the following:
Opening Ceremonies (broadcast by ABC)
International Dance System (live dance music for the athletes)
VIP Reception jazz concert
Lunch time entertainment systems (live music)
Athletic-event systems
Awards systems
Olympic Town — a week-long series of concerts, 5 to 6 hours per day.
Nearly all the microphones in use were Crown CM-200 [now the CM-200a] cardioid condenser units.
According to Bill Raventos (Crown’s Microphone Product Director), Tom Durell was “ecstatic” about
the CM-200’s. Several sound engineers said that the microphones sounded “great.” They were used
everywhere, for instruments as well as vocals. The mics were reported to have no breakup, even
when used on musical instrument loudspeakers.
CM-200a
Crown Select Series wooden-handle microphones [discontinued] were custom engraved with the
names of the participating celebrities. Oak-handle units were presented to Barbara Mandrell, Oprah
Winfrey, Whitney Houston, John Denver, Don Johnson, and Jeff Margolis. Craig Golins received a
microphone of ziricote wood, and Lee Miller used one made of laminated birch.
Don Johnson was so impressed by the CM-200 he used that he showed it to Eunice Shriver. Mrs.
Shriver later called Crown’s Margo Sousley, asking if her daughter, Maria (also a participant in Olympic ceremonies), could have a mic with her name engraved on it.
IN ALL, THE OLYMPICS USED 92 CM-200’s, 5 CM-100’s, 20 CM- 300’s, AND 10 GLM-100’s.
We’re proud that Crown microphones played a vital part in the success of the 1987 Summer Special
Olympics.
HOW TO USE A CM-300 DIFFEROID MICROPHONE [now the CM-310a]
Sing close to the microphone.
The Crown CM-300 Differoid is a differential cardioid microphone that cancels distant sounds. Consequently, it must be used close up — lips touching the grillescreen. In addition, the user should sing
directly on-axis, into the front of the microphone. Otherwise the singer’s voice will be cancelled or
sound thin.
By taking these precautions, the user will experience phenomenal gain-before-feedback: up to 12 dB
more than comparable microphones.
NEW GLM ACCESSORIES
Three useful new accessories for GLM microphones have been just introduced:
*GLM~TM Tie Mount. This is a clip-on mount for ties and clothing that lets the GLM swivel to any
desired position. Unlike the older, fixed Tie Mount, the new mount lets the user place the clip anywhere on the shirt or necktie while still aiming the GLM at the mouth. The new TM will be included
with all GLM-100 and GLM-200 microphones.
*GLM-SP Stick Pin Mount. This mount lets the user fasten a GLM-100 to clothing by pinning the
mount to fabric. The SP will be included with all GLM-100’s.
*GLM~SM Surface Mount. This accessory converts a GLM for boundary miking, either on musical
instrnments (guiitar, banjo, piano) or on plexiglass boundaries.
GLM-SM Surface Mount
With the GLM-SM, you can mount a GLM-100 omnidirectional microphone face-down nexi to a
surface or boundary. This effectively converts the GLM-100 into a Pressure Zone Microphone, eliminating phase cancellations due to delayed sound reflections from the boundary. The polar pattern of
the GLM-100 mounted PZM-style is hemispherical.
The GLM-SM Surface Mount also lets the user mount a GLM-200 hypercardioid microphone on-edge
next to a surface. The axis of the microphone is parallel with the surface. With this mounting, phase
cancellations due to surface reflections are moved above the audible range. The polar pattern of the
GLM-200 mounted this way is half-hypercardioid.
GLM-SM Surface Mount used to make a hypercardioid boundary mic.
Packed with the GLM-SM are several pieces of double-sided foam tape. Each piece goes between
the mount and the body of a musical instrument to prevent rattles when the instrument is played. To
attach a GLM-SM to a plexiglass boundary, use ordinary duct tape or drafting tape.
MICROPHONE POLAR PATTERNS
The polar pattern of a mIcrophone is a graph showing how the mic responds to sounds coming from
different directions. The graph is a plot of microphone sensitivity in dB vs. angle of sound incidence.
Polar pattern: Omnidirectional.
Omnidirectional microphones are equally sensitive to sounds coming from all directions. Unidirectional
microphones are most sensitive to sounds coming from one direction — in front of the microphone.
Polar pattern: Cardioid.
Three types of unidirectional patterns are the cardioid, supercardioid, and hypercardioid pattern. The
cardioid pattern has a broad pickup area in front of the microphone. Sounds approaching the side of
the mic are rejected by 6 dB; sounds from the rear (180 degrees off- axis) are rejected 20 to 30 dB.
The supercardioid rejects side sounds by 8.7 dB, and rejects sound best at two “nulls’ behind the
microphone, 125 degrees off-axis.
Polar pattern: Hypercardioid.
The hypercardioid pattern is the tightest pattern of the three (12 dB down at the sides), and rejects
sound best at two nulls 110 degrees off-axis. This pattern has the best rejection of room acoustics,
and provides the most gain-before-feedback from the main sound reinforcement speakers.
Choose omnidirectional mics when you need:
All-around pickup
Pickup of room acoustics
Extended low-frequency response (in condenser microphones)
Low handling noise
Low wind noise
No up-close bass boost
Choose unidirectional mics when you need:.
Selective pickup
Rejection of sounds behind the microphone
Rejection of room acoustics and leakage
More gain-before feedback
Up-close bass boost (proximity efr fect)
An omnidirectional boundary microphone (such as a PZM) has a half-omni or hemispherical polar
pattern. A unidirectional boundary microphone (such as a PCC-160) has a half-supercardioid polar
pattern. The boundary mounting increases the directiionality of the microphone, thus reducing pickup
of room acoustics.
LETTERS FROM CROWN MICROPHONE USERS
Crown mics in Puerto Rican theater
I am a sound technician for the Teatro Yaguez Municipio of Mayaguez. It is the best theater in the
western area of Puerto Rico. The theater was built in 1919 and remodeled in 1976 with federal and
municipal funding. We have modern electronic equipment, including many Crown microphones. We
are proud of doing our work for the Theater Yaguez. Best wishes to Crown.
Jaime Ruiz Placido, Theater Yaguez, Mayaguez, Puerto Rico
Sound Grabber for camcorder
We recently purchased a Sound Grabber PZM microphone for our video camcorder as an external
mic. We were dissatisfied with the camcorder built-in mic’s performance, as it picked up motor hum. I
place the PZM in my shirt pocket while taping, and get excellent results.
We’ve tried all kinds of TV appliance stores for mics, and I’m glad we stumbled onto yours. It is a fine
piece of equipment which we are proud of. Keep up the good work!
Darwin L. Hjort, Stacy, Minn
Sound Grabber is convenient for interviews
This past year you donated some Sound Grabbers to the Summer Institute of Linguistics-Wycliffe
Bible Translators. I received one of these microphones.
I am investigating one of the Indian Languages of Mexico. While sitting at a desk with one of my
Indian helpers, I find it convenient not to hold a microphone to her mouth. By just leaving it on the
table in front of her, I can record with enough quality to hear the sounds of the words that I need to
hear to do my investigations.
And if I need to make comments, I can do so without bringing the microphone to my mouth. I can just
make the recording from where I sit at the other end of the desk.
Larry R. Harris
###
MIC MEMO
April, 1988
Bruce Bartlett, Editor
“BAD” MICROPHONES
Clair Brothers, the superstar sound-reinforcement company, is using Crown CM-300 Differoid microphones [now the CM-310a] on the current Michael Jackson tour for background vocalists.This tour
promotes Jackson’s recent album, “Bad.”
The singers were having a problem with feedback and lekkage because of high stage-monitor levels.
Other microphones were tried, but only the Differoid provided enough isolation and gain-before-feedback.
The Differoid is a differential cardioid condenser microphone for hand-held vocals. It cancels distant
sounds and rejects sounds approaching the rear of the mic. This permits very high monitor levels
without feedback. By rejecting background noise on stage, the microphone lets the mixer operator
“pull the mic out of the mud.” That is, a vocal can be brought up clearly in the mix without bringing up
everything else along with it.
When the Differoid was first tried, console problems caused the mic to be underpowered, so that it
faded out after half an hour. Engineers from Crown and Clair Brothers worked together toward a
solution. We determined that the house-console phantom supply needed some re-design to perform
closer to DIN standard. Also, since the microphone was paralleled to feed two consoles, one console
loaded down the other, causing the phantom voltage to sag to 5 volts! See the article “PhantomPowering Precautions” in this issue for more detail.
To temporarily solve the problem, the Differoid was powered from both consoles. Gene Clair said that
the Differoid sounded “great,” had no feedback problems, and projected the vocals clearly. Not bad!
PHANTOM-POWERING PRECAUTIONS
There’s a new problem with phantom powering condenser microphones, and it could affect you. It’s
becoming more common with today’s multi-console systems, in which you “Y” or split a microphone
signal to feed more than one console in parallel. In this case, the phantom-supply voltage may drop
from, say, 48 volts to 5 volts — too low for the microphone to operate properly. You’ll hear distortion or
level loss.
There are several ways to solve this problem of power-supply sag. But to understand them, we need
a brief review of phantom powering itself.
Definition
A phantom-power supply is a circuit that supplies DC powering (12-48V) to condenser mics, using the
same conductors as the audio signal. The microphone receives power from, and sends audio to, the
console along the same cable conductors. Phantom power operates the microphone circuitry. In an
externally biased mic capsule, phantom power also is used to polarize the condenser transducer.
(Microphone capsules using the electret or RF principle do not need external polarization, but the mic
circuit still needs power.)
If a stand-alone phantom supply is not used, power is applied to each mic connector in the console,
and is usually switchable ON or OFF for each input.
Two types of remote powering are phantom and AB. Phantom, the most common, is a positive voltage
on pins 2 and 3 with respect to pin 1. The cable shield is the supply return. This is DIN standard 45
596, which is called “multiplex powering.” (Apparently the terms “phantom” and “multiplex” are interchangeable - we welcome letters clarifying this subject). Pin 1 is ground; pin 2 is audio in-phase, and
pin 3 is audio return. Although the audio signal has polarity, phantom power has no polarity because
both pins 2 and 3 have the same positive DC voltage.
Fig. 1. Phantom voltage applied through two equal resistors.
Fig. 2. Phantom voltage appllied through a center-tapped transformer.
The phantom voltage is applied either through two equal resistors to pins 2 and 3 (Fig. 1), or through
a resistor to the ungrounded center tap of the microphone input transformer (Fig. 2).
AB remote power (used in some Sennheiser RF condenser shotgun mics) applies positive voltage to
pin 2 and negative voltage to pin 3. This is DIN standard 45 595, modulation-lead powering. AB powering is used almost exclusively in the motion-picture industry in the
U.S.A.
Causes of Power Supply Sag
There are at least two causes of power-supply voltage loss that occurs when a mic is plugged in:
1. The phantom supply in the console is improperly designed.
2. If the mic inputs of two consoles are connected in parallel, the mic input of the second console
might be loading down the power supply of the firsL That can occur as follows: When the second
console’s phantom is switched off, a bleeder resistor is switched across the capacitor connected
across B+ (Figure 3). This resistor draws excessive current from the other console’s supply, dropping
its voltage.
Fig. 3. Phantom supply with bleeder resistor.
Solutions:
1. If there’s a resistor between B+ and the two equal resistors that go to mic-connector pins 2 and 3 in
the console, remove (short) that resistor. The microphone may pop when it’s plugged in, but at least it
will work.
2. Supply phantom from both consoles (use caution).
3. Supply phantom from the console that is better regulated (assuming that the consoles don’t load
down each other), or
4. Use a transformer-isolated mic splitter (expensive but effective).
Phantom Power-Supply Design
If you’re adding phantom power to your own customized console, you can use two methods:
1. Apply phantom power through two equal resistors to pins 2 and 3 (Figure 1).
2. Apply phantom power through one resistor to the ungrounded center tap of the input transformer
(Figure 2).
What value resistors should you use? The table below answers this question. It’s based on DIN specification 45 596.
Many thanks to Gene Clair and Ron
Barthwick of Clair Brothers for their help and suggestions about this problem.
For 12V supply voltage, use 680 ohms for 2-resistor ckt; use 340 ohms for C.T. transformer.
For 24V supply voltage, use 1.2 kilohms for 2-resistor ckt; use 600 ohms for C.T. transformer
For 48V supply voltage,use 6.8 kilohms for 2-resistor ckt; use 3.4 kilohms for C.T. transformer.
GLM-200 CHOIR MIKING
The Crown GLM-200 miniature hypercardioid condenser microphone provides high-fidelity, inconspicuous miking of a choir. The microphone practically disappears in use. Its hypercardioid polar
pattern increases gain-before-feedback in sound-reinforcement systems.
Don Peterson, Crown’s National Service Manager, provided this suggestion on miking a choir with
Crown GLM-200 microphones:
First, you might want to modify the microphone for flat response as described in Crown Technical
Bulletin No.1 [discontinued].
You can either hang the microphone from its cable or mount it on a boom mic stand. You might want
to experiment with placement using the mic stand, then hang the microphone after finding a suitable
position.
If you’re hanging the microphone, first tilt it back to pick up the front row and to reduce echo from the
wall behind the choir. To do this, bend a brazing rod or a coat hanger as shown in Fig. 4, and attach it
to the GLM-200 cable with shrink tubing.
Hanging device for GLM-200.
Fig. 5. Choir mic positions.
We recommend the following placement as a starting point (Fig. 5): Using two microphones 10 feet
apart, locate them about 1-1/2 feet in front of the front-row musicians, and 1-1/2 feet above the heads
of the back-row musicians. If feedback is not a problem, you can place the mics farther from the choir
to improve the blend.
You may want to attach a 5-lb. nylon fishing line between the side walls adjacent to the choir, and tie it
to both microphones to stabilize their direction. Fasten the line to the side walls slightly below the
GLMs to provide a slight downward pull.
GLM-1OO/E microphones with 40' cables are available from Crown on special order. Using this long
cable lets you locate the connector/electronics out of sight. [Currently available from Crown are the
CM-30 and CM-31 choir mics. They have less self-noise than the GLM-200.]
CLOSE-MIKING A SYMPHONY
When miking a symphony orchestra; most engineers would use a few microphones overhead and out
front. But when this method was tried last July on the Atlanta Symphony playing with the Temptations,
it didn’t work. Leakage of the monitor speakers into the overhead mics caused a hollow reinforced
sound. This problem was compounded by sound reflections from the band shell.
William “Billy T” Talarico, sound engineer for the Temptations, had a better idea. He thought of tightmiking the symphony, and suggested that idea to Walt Wynn, who is a sound contractor associated
with the Atlanta Symphony. They tried it. According to William, “It was really successful... The orchestra sounded like Vegas strings.” The symphony members enjoyed the sound too.
William used all Crown GLM-200 miniature hypercardioid condenser mics. They were set to a bright
frequency response for the strings (as supplied from the factory) and to a flat response for everything
else. Since the orchestra members did not want anything attached to their instruments, the mics were
attached to boom stands with goosenecks.
Although distant miking works well for recording orchestras, tight miking is demanded in unusual
circumstances, such as reinforcing an orchestra playing with a pop group.
PCCs COVER PHILADELPHIA’S MUMMER’S DAY PARADE
Here’s a tough one: How do you pick up a good balance on an enormous marching band parading
down the street? That problem was addressed by KYW-TV 3 in Philadelphia. Ron Little, KYW-TV
Production Manager, worked on this project with help from Crown’s Microphone Product Director, Bill
Raventos.
KYW provided coverage of the Mummer’s Day Parade which is held every New Year’s Day. This
parade is something like Mardis Gras, with vocal performers, string bands, and symphonic bands. It
runs from 8 AM to 8 PM with continuous TV coverage.
For the main stereo pickup, Ron used a pair of PCC-160 supercardioid boundary microphones placed
back-to-back on a 2-foot-square piece of plexiglass. To reduce wind noise, the plexiglass boundary
was wrapped in acoustically transparent fabric. The PCC’s bass-tilt switch was set to “flaL”
This arrangement was suspended on cables 32 feet over the street, and 24 feet in front of the performance line of the bands as shown in Figure 6. A similar array was mounted on a boom standing in the
middle of the groups’ performance area.
Fig. 6. Parade miking setup.
Two backup mics were also mounted on the same boundaries, making a total of 8 mics used. Backup
mics were needed because it would have been impossible to change a mic in the middle of the 14hour performance. Four microphones contributed to the final mix.
KYW-TV 3 used phantom power from the remote-truck board. Since they didn’t want any break or
connectors between the mics and the truck, they made two cables which ran from the mics directly
back to the truck, so that the lines were unbroken.
According to Ron, “We achieved excellent results. The stereo mix and balance by far surpassed our
1987 parade coverage where we had used conventional mics, shotguns, etc. I do believe we have
found the proper answer to the audio situation. KYW-TV is proud of the resulting coverage of this
year’s parade, and hope that Crown also feels some measure of pride for the part they played.”
LETTERS FROM CROWN MICROPHONE USERS
Mic for voice-over
I always enjoy keeping abreast of today’s fast-paced advances in audio technology and especially my
most important tool of trade — the microphone. I maintain a small audio studio facility in my home, the
sole purpose of which is voice-over production. Among other things, I have a Crown PZM and an AKG
414. (also have a couple of RCA 44’s and 77’s as a reminder of those good old days.)
Browsing through the December issue of Mic Memo, my eye was drawn to the piece re: “How to Use
a CM-300 Differoid Microphone.” In pondering over the interesting details, I couldn’t help but wonder
what the Crown experts would prescribe from their stable of equipment as the ideal microphone where
the prime use is voice-over?
I realize of course that today’s recommendation may well be outmoded by tomorrow’s advances, but I
just had to pop the question. Any response at your convenience will be appreciated; meanwhile I look
forward to the next issue of Mic Memo.
John J. Strader, JJS Enterprises~Productions, Cincinnati, Ohio.
Reply:
Several Crown microphones can be used for voice-over, depending on your application:
*For a lavalier mic, the CM-10.
*For a boom-mounted cardioid mic, the CM-200a (with its foam pop filter) or the CM-700 (with a hooptype pop filter).
*For a boundary microphone, the PZM30D.
All these are condenser microphones and require 12-48V phantom power, either from your console, or
from a Crown PH-4B or PH-1A phantom power supply.
The CM-10 lavalier is worn by the user, so it remains a constant distance from the mouth, which aids
consistency. There’s no problem with breath pops. When using it, angle the script stand away from
the user so that the sound does not reflect back into the mic and cause phase interference. Ask the
announcer not to move his or her head, if possible, because this can change the tone quality.
Place the CM-200a or CM-700 cardioid mic about 8 inches from the user, with the microphone perpendicular to the script stand. This way, sound reflecting off the stand is rejected by the “dead” back
side of the microphone. Position the mic off the axis of the mouth to prevent breath pops. Use a
spacer to ensure that the announcer maintains a constant distance to the microphone for every recording.
Tape the PZM-30D to a 2-foot-square script stand. Take care not to make too much paper noise when
you turn the script pages. The sound may be a little thin due to the small boundary.
Let us know how these suggestions worked. Good luck!
Padding down a Sound Grabber
When quality is not important, I often use a “boom box” recorder with my Sound Grabbers. However,
the automatic level control is really activated by them. What kind of pads could I build that would cut
the level about 10 dB?
Gary Wakenhut, Lakeview, MI
Reply:
Try the 10 dB pad shown in Figure 7. For more loss, increase the value of the 2200-ohm resistor, or
decrease the value of the 1000-ohm resistor.
Fig. 7. Sound Grabber 10 dB pad.
Reducing vibration, reducing highs
We have a couple of problems with our Crown microphones.
1. The GLM-200 microphones when used with the GLM-OHM boom assembly have extreme sensitivity to low-frequency vibration, so much so that walking across the stage or studio floor is a problem.
Have you any recommendations on attaching the mics to the boom assembly so as to effectively
decouple the microphones from the boom-stand-floor?
2. The PZM-20RG microphone has excessive high-frequency response which, rather than contributing
to intelligibility, makes the unit extremely prone to feedback even at moderate gains. Have you any
recommendations on attenuating the high-frequency peak?
Anthony J. Gnazzo, Department of Music, University of California, Berkely, California
Reply:
1. Tape the GLM cable to the boom arm so that the capsule is held only by its cable, and can vibrate
freely. Or isolate the boom stand from the floor by mounting the stand on sponges or foam rubber. The
thicker the sponges are, and the smaller their ‘foot-prints” are, the better the isolation is.
2. The PZM-20RG was designed for maximum intelligibility for conference recordings, but if feedback
is a problem with sound-reinforcement, try the following solutions:
Cut out a thin rectangle of open-cell foam (such as used in microphone windscreens). Using a sharp
knife or razor blade, gently insert the foam fully into the gap under the microphone cantilever. The
thicker the foam, the more the high-frequency rolloff If this is not possible, put thick foam around the
nose of the cantilever to attenuate the highs.
###
MIC MEMO
August, 1988
Bruce Bartlett, Editor
PZMs WIN FOUR EMMYS!
Crown PZM microphones helped their users win four Emmy awards in the last three years. These
were:
1. The April 1985 award for a December 1984 music recording by Gary Pillon, General Television
Network, Oak Park, Michigan.
2. The May 1987 award for a December 1986 music recording by Bill Samples, WJRT Tv-12, Flint,
Michigan.
3. The May 1988 award for a December 1987 music recording by Bill Samples.
4. The May 1988 award for a June 1986 documentary recording by Gary Pillon (tied with Bill
Samples).
Bill Samples won two Emmys, one year apart, for the same type of recording: the Saginaw Symphony
pops concert held in the Saginaw Heritage Theater. Patterned after the Boston Pops’ Christmas
concerts, the Saginaw concert added a 125-member choir on the second occasion. Program material
ranged from “Go Tell It on the Mountain” to “The Halleluiah Chorus.” The show was simulcast over a
local PBS radio stafion.
Bill used PZMs because they were aleady in use at the Saginaw Heritage Theater, and the theater’s
sound engineer recommended them. The first year, Bill used the theatre’s two PzMs on a “wedge” or
V-shaped plexiglass panel (Fig. 1). The wedge consists of two panels (each 2-feet square), angled 60
degrees apart. The point of the V aims at the sound source. Even though the two PZMs were not the
same model and differed in sensitivity, the recording won an Emmy!
Fig. 1. PZM wedge.
The second year, Bill bought three PZM-6R [now PZM-6D] microphones, the small-plate unit with a
rising high-frequency response. In addition to the PZMs on either side of the wedge, he placed a third
unit in the middle of the back side to pick up hall reverberation (Fig. 2). This array was suspended 15
to 20 feet over the front row of musicians, even with the curtain line. Bill noted that the band shell
focused sound on the PZMs, so that there was less need for spot mics.
Fig. 2. PZM wedge with rear pickup.
To compensate for the low-frequency shelf of the 2-foot boundaries, he boosted +6 dB at low frequencies. Another PZM was used on the floor to pick up a madrigal group. Bill used spot mics on certain
choir members, violins, and percussion.
According to Bill, the PZMs “did an excellent job,” with “super separation” and “unbelievable stereo.”
Gary Pillon used a similar PZM wedge (with two microphones) to record the Fort St. Chorale and
Orchestra performing the syndicated PBS program, “Miracle on Fort Street,” which featured Handel’s
Messiah. The recording venue, Fort St. Presbyterian Church in Detroit, was a cinderblock-and-wood
building dating back to the late 1800’s - a marvelous acoustic space.
Gary used two stereo pairs of PZM-6S [now PZM-6D] (Fig. 3). A 60-degree wedge was placed about
10 feet behind the conductor and 17 feet high. It was anchored by two bungee cords from the top of a
Mole Richardson Hi-Riser. This placed the wedge even with the overhead chandeliers, out of camera
view except for an extreme wide shot.
Fig. 3. Mic setup at Fort St. Chorale recording.
In addition, an L2 array (Fig. 4) designed by Mike Lamm of Dove & Note Recording in Houston was
placed on apple boxes and sandbags 8 feet behind the conductor. It picked up the sound coming
directly from the orchestra and augmented the soloists, who stood on each side of the Maestro, facing
the 800 people who packed the two levels of the church.
Fig. 4. L2 array.
To our ears, the recording sounded spacious, with a full stereo spread, good localization, and a midaudience perspective. The acoustics suited the music well. Tonal quality was full and smooth, and the
balances among the orchestra, choir, and soloists were just right.
Gary’s second Emmy was for a half-hour documentary on the Michigan Muzzleloader’s Festival. This
three-day conclave occurs every June at Greenfield Village, Michigan. People from around the country
come to re-enact the past in period costumes, lifestyle, and a black powder shooting contest.
Gary devised a stereo PZM shotgun consisting of two PZM-6S [now PZM-6D] cantilevers mounted in
a special Lexan array. The two mics are 8 inches apart, and each is fitted in the apex of a pyramidshaped structure (Fig. 5). Two models were made, small and large, which fed a Sony Betacam.
Fig. 5. Pillon PZM stereo shotgun.
The larger unit was used on a televison “C” stand, which gave ten-foot high overviews of the
weekend’s events, such as parades, marching bands, and gunfire. This mic also had a pistol grip for
handheld use to pick up dialogue.
The smaller version was mounted under the lens of a Sony Betacam on a Steadicam platform (the
first application of this type). The audio perspective was a perfect match to the field of view given by
the wide-angle setting of the zoom lens. While the mic picked up sound from all over Greenfield Village, the central sonic image always matched the picture. In post production, Gary equalized the PZM
stereo shotgun for a flatter response.
Burr Huntington of Sound Moves was Gary’s partner, providing mid-side stereo pickup which was also
used in the program.
This sound track was the finest we have ever heard for a television documentary. The dialogue was
clear; sound effects were stunning in their realism, and stereo imaging was sharp and effectively used.
We congratulate Bill and Gary for their Emmy awards, and thank them for sharing their PZM techniques with us.
PZM MODIFICATION FOR PURISTS IMPROVES SOUND QUALITY
Here’s a modification for any PZM that makes an audible improvement in sensitivity, frequency response, and clarity. We first suggested it to Pierre Sprey, an audiophile PZM recordist for Maple
Shade Studio, Glen Dale, Maryland. He tried it and was delighted with the results.
This modification is for audio purists who are willing to put up with the following disadvantages:
*You need unbalanced mic inputs with an impedance of 10 kilohms or higher.
*The circuit works on 9V batteries rather than phantom power.
*Total cable length should be under 25 feet. Use audiophile-grade cable.
*The handmade circuit may not have the professional look of a manufactured product.
*You might void the microphone warranty.
You also need direct access to the mic capsule leads. In older PZMs that have an in-line interface
(interface PA-18, PX-18, or PX-T), the capsule leads go directly to the XLR-type connector in the
microphone cantilever. You can plug a female 3-pin connector into the PZM 3-pin connector to connect to the mic-capsule leads.
In newer PZMs having a built-in interface, you must remove the interface from the microphone or mic
connector and unsolder the capsule leads from the printed circuit board. NOTE: This will void the
warranty.
Build the circuit shown in Fig. 6. For older PZMs with an external interface, connect the shield to pin 1,
the B+ lead to pin 2, and the audio lead to pin 3. For newer PZMs with a built-in interface, connect the
shield to the grey lead, the B+ lead to the red lead, and the audio lead to the orange lead.
Fig. 6. Schematic for PZM powering system.
The mic capsule is powered by bipolar power (+/- 9v). Since the impedance-matching transformer is
missing, the microphone impedance will be 1.14 kilohms, which is still low enough for short cable
runs.
According to Pierre, the results are superb. Sensitivity is increased 11 dB; S/N is improved (by overriding mixer noise), the treble is cleaner and sweeter, and the low end is more detailed. Presumably,
all these effects are due to omitting the impedance-matching step-down transformer.
Pierre also reports that the Sound Grabber can be powered by two 6V photoflash batteries for greater
sensitivity and headroom.
INDY 500 USES CROWN MICROPHONES
Over this Memorial Day weekend, a half-million people watched the Indianapolis 500, the world’s
fastest auto race. Crown shared its equipment and technology with audio people connected with the
race.
The high-level P.A. was provided by three Crown MacroTech 10,000 power amplifiers. Four are installed; one is a standby unit.
All track announcers were heard through CM-300 [now CM-310a] Differoid microphones. A CM-200
[now CM-200a] cardioid microphone was used for Opening Ceremonies and for the interview with
winner Rick Mears. A pair of GLM200/EQR [now GLM-200] microphones were prepared in an X-Y
configuration for stereo pickup of some of the pit stops. The evening after the race, the LM-190 [now
LM-300] lectern microphone provided audio for the official banquet.
Crown received glowing endorsements from the President of the Indy 500 and the chief track announcer. In addition, the Indy 500 radio network broadcast “Thank you” messages mentioning Crown.
The following is from a letter to Crown from John Royer (with the Indianapolis Motor Speedway Radio
Network):
“We greatly appreciate getting to use the Crown microphones. As usual, the PZMs, the CM-200s and
the CM-300 all worked great. The LM-190 is truly unbelievable: for the first time at the Victory Banquet
you could actually hear the drivers speak.”
Chief track announcer, Don Carnegie, had this to say about the CM-300 [now the CM-310a Differoid.]
“This microphone is the finest I’ve ever used in 43 years of broadcasting on the world’s largest P.A.
system. Believe me, this microphone... is compatible with the job that we have to do to inform on
qualifying day a crowd of some 250,000, and on race day a crowd in excess of 400,000. In short, I
love it. And whoever put it together, let me have one each and every year. That’ll keep me coming
back to the track.”
###
MIC MEMO
November, 1988
Bruce Bartlett, Editor
AN IMPROVED DIFFEROID MICROPHONE: THE CROWN CM-310 (now
the CM-310A)
Crown has improved the CM-300, a differential cardioid handheld microphone that provides outstanding gain-before-feedback and isolation. The replacement model, CM-310, has
*significantly lower noise
*higher SPL capability (151 dB!)
*lower current drain
*a smoother high end, and
*a warmer tonal balance.
The external appearance is identical:
CM-310
All this has been achieved without sacrificing gain-before-feedback. In fact, during a field test of a
CM-310, a monitor-mixer engineer for a major tour gradually turned up the CM-310 gain until the
monitor-speaker level was more than he could stand. “Stop!” he said, “This microphone does not feed
back!”
Of course, the CM-310 can be made to feed back, but at monitor levels that may be hazardous to the
speaker drivers. Use with caution.
A technical paper of the development of this microphone will be presented at the November Convention of the Audio Engineering Society.
MILES DAVIS RECORDED WITH CROWN PZMs
How do you mike a trumpeter who won’t stand still? Miles Davis moves around while he plays, which
forces engineers to find novel solutions. Clipping a microphone to the bell can yield an unnatural tone
quality compared to distant miking.
A solution was found by engineer Steven Strassman and producer Marcus Miller working on Miles’
album, Siesta. They taped Crown PZMs to the walls all around the trumpeter.
According to Miller, “We put them all over the place and worked out the phasing, and that way Miles
could go wherever he wanted. We got a really warm sound. The room we worked in was small, so he
couldn’t get too far away. When he was playing into the [stand-mounted] mic, it was fine, and when he
didn’t feel like playing in the mic we’d just raise the [level of the] PZMs and catch him off the walls. He
couldn’t get away from a microphone.
“I used the same mics on the bass clarinet. I’d play to one mic on the wall, and it sounds real interesting. It gets all the air. When I play bass clarinet there’s a little bit of air that escapes out of the corner
of my mouth - a problem I never bothered to correct from high school - but it works really well on
something like this because it gives it this sizzle at the top.”
PZM CHOIR PICKUP
Leroy Shine of Shine Sound has devised an effective way to reinforce choirs with PZMs. He starts
with a plexiglass boundary measuring 1 1/2 feet x 2 1/2 feet. Then he adds an Atlas studio mic stand
with a heavy triangular base and a right-angle boom. A flange on the back of the boundary screws
onto the boom.
Figure 1 shows the setup. A PZM is mounted near the top of the boundary. This boundary is raised so
that its bottom is just above the heads of the front row, 3 to 4 feet in front of them. The boundary is
angled to aim at the back row, so that closer voices are more off-axis.
Fig. 1. Leroy Shine’s method of miking a choir with PZMs.
According to Leroy, he gets a balanced, even blend of all three rows on risers, with good gain before
feedback. He employs up to six boundaries for choirs of 750 people.
This arrangement has been used for Rev. James Cleveland’s Gospel Music Convention, consisting of
many different groups singing about ten minutes each.
Choir members can hear themselves due to reflections off the boundary. Plus, visual reflections reveal
any deadpan faces!
PCC LEGISLATURE INSTALLATION
When the chambers of the Alberta, Canada Legislature were being revamped for television, a new
microphone system was needed. Don Scheirere and Comtec Associates were called in to design and
install the system. They mounted a total of 93 Crown PCC-l60’s in members’ desks, conference
tables, and the Speaker’s chair.
In the Omnimedia publication, “Audio Directions” (Aug.’88), Don describes why he chose the PCC-160
for this job:
“We looked at all the big names in microphones. Primarily we needed something that would meet the
aesthetic requirements: low profile, something that was non-microphone in appearance, that could be
fitted into the architecture of the desks that wouldn’t take away from the refurbishing. My prime consideration was something that would give us a good presence from a distance and that could take
advantage of the surface. What it basically came down to was that it had to be supercardioid and
have a decent response.
“It also had to be something that could take a lot of thumping because the members, as they respond,
are banging the desks. The other factor that we had to contend with, and you will anytime there’s an
assembly or debating situation, is that the darn thing is going to have to handle some dynamic range
(115-120 dB SPL) without distortion.
“The PCC-l60 met those requirements. What makes it unique is that you can build it into the architecture without it looking mic-ish. We did the same job for the Saskatchewan Legislature only we used
another brand of mic of conventional design. It works fine but the PCC-l60 is better. It gets far better excellent - presence. That’s what everybody comments on. They hear the stuff at home and it sounds
like the guy is sitting right there. I wish we had had access to it on the Saskatchewan job.
“We’ve also used the PCC-160 in the studio and put it into conference rooms with excellent results.”
PHANTOM FIGURE CORRECTION
In the April ’88 issue of Mic Memo, there was an error in Figure 3 in the article “Phantom-Powering
Precautions.” It should have appeared as shown in Fig. 2 below.
Fig. 2. Correction to phantom-power circuit.
Note that the 51-ohm bleeder resistor is not a good idea. If the mic inputs of two consoles are connected in parallel, the bleeder resistor of the second console can load down the phantom supply of the
first console. That resistor should be increased in value or omitted entirely.
PZM/PCC USERS
Crown PZMs and PcCs have been used in a wide variety of applications. Here are just a few of their
users:
Miscellaneous
Wayland Baptist University
Aetna Insurance Co. - teleconferencing
Starlight Theater, San Diego
Long Beach Symphony
“42nd St.” show at Kennedy Center
San Diego Opera
Wolf Trap
San Francisco Opera
University of Denver Miracle Theater Co.
LA Philharmonic
Syracuse Symphony
Atlanta Symphony
Opera Theater of Syracuse
Cerritos Community College
Downey Civic Light Opera
Moravian College of Music
Las Vegas Hilton - show band
Christ Covenant Church, Greensboro, NC - piano and kick drum
Palm Desert City Council Chamber
Superbowl (coin toss)
Indy 500 - race track
Imax film on NASA space shuttle
Paragon Music Center, Florida
Dave Andrews Audio
Theater Yaguez, Mayaguez, Puerto Rico
Harrahs Marina Hotel Casino
Recording Studios
Las Vegas Recording
Tres Virgos Studios
Wally Heider Studios
Ryder Sound Services
Dave Andrews Audio Consultants
Dove & Note Recording, Houston
Award Shows
American Music Awards & Grammy Awards (piano)
Academy Awards (audience)
Amusement Parks
Six Flags Over Texas - live gunfight show
Leisure Village, Camarillo, CA
Ringling Bros.
Universal Studio Tours - live gunfight show
Recordings
Pan Is Beautiful III - steel drum contest
Flim & The BB’s - “Tricycle”
Beach Boys LP - “Keeping the Summer Alive”
Willie Nelson LP - piano
Debbie Boone LP - strings
Bill Gaither Trio - “Live at Grand Old Opry”LP - drums
Mel Torme - audience reaction
Frank Zappa - London Symphony
Barry Manilow - piano
Shelly Manne - drums
Average White Band - lead vocal
Buddy Rich - “Live at King Street” LP - drums and brass
Radio and TV
WJRT TV-12, Flint, Michigan (Two-time Emmy winner)
KPHO, Phoenix - Fiesta Bowl National Pageant of Bands
KSOR, Oregon
KZLA, Los Angeles
WSKG/FM/TV - symphony recordings
WGCI, Chicago - talk shows
ABC-TV
National Public Radio
America Radio Theatre
KYW-TV 3 Philadelphia (Mummer’s Day Parade)
PBS
General Television Network, Detroit (Two-time Emmy winner)
TURN YOUR SOUND GRABBER INTO A STUDIO MIC
Here’s a modification for the Crown Sound Grabber that converts it into a studio-quality microphone.
We first suggested it to Pierre Sprey, an audiophile PZM recordist for PMS Inc. in Maryland. He tried it
and was excited with the results. The Sound Grabber was originally designed for noncritical conference recording, but it can be upgraded for musical applications. This modification is for audio purists
who are willing to put up with the following disadvantages:
*You need unbalanced mic inputs with an impedance of 7 kilohms or higher.
*Total cable length should be under 25 feet.
*You will void the microphone warranty.
Referring to Fig. 3, please proceed as follows:
Fig. 3. Sound Grabber enhancement.
I. Open the Sound Grabber and locate the printed circuit board near the cable end. Remove it by
cutting away the sealant.
2. The circuit board contains a 2.2 kilohm chip resistor and a chip capacitor. Replace the resistor with
a 2.2 kilohm metal film resistor for lower noise.
3. If your mixer input is capacitor coupled, short the chip capacitor. If not, replace it with a 1 microfarad
polypropylene capacitor. This extends the bass response to 30 Hz. And, Pierre says, the polypropylene capacitor has less veiling effect on the high end than the chip capacitor. (Poly caps are big and
probably won’t fit inside the mic.)
Pierre also has glued open-cell foam around the edges of the gap near the capsule to reduce its highfrequency rise. Plus, he has damped the underside of the plate with lead.
Using the Sound Grabber without a boundary, Pierre aims the nose of the microphone at a singer or
sax player. This orientation gives a more natural sound (a flatter response) by avoiding the 3 kHz
peak due to sound diffraction of the plate built into the microphone.
“It’s a first-class microphone for music,” he reports. According to Pierre, the modified Sound Grabber
has more mid-bass articulation on voice and sax than larger-diaphragm mics (such as the Sony C37
or Neumann U 87i), which tend to smooth over this area. The Sound Grabber’s reproduction is more
clearly delineated and has a better transient response. Pierre also notes that two Sound Grabbers can
be paralleled without problems.
LETTERS FROM CROWN MICROPHONE USERS
Talk-show miking
Here at the Illinois Bell Corporate TV Center, we produce over 200 video programs every year, covering every topic from financial affairs, to corporate safety, to a monthly news magazine for employees.
For years, we have relied on multiple-microphone layouts for our studio programs, but in the last year,
we have switched to a new application that not only makes things much more comfortable for our
executives and guests, but provides excellent overall signal as well.
Since a good number of our interview programs involve from two to five people, we switched our
format from multiple chairs placed in a “Talk Show” style to gathering the principals around a mediumsized table for “round-table” discussions. After wrestling with the multiple-mic proximity problems that
this produces, we covered the tabletop with a neutral-color carpet-like set material, cut a flap, drilled a
1" hole through the tabletop, and placed a single PZM-3OGP [now PZM-30D] microphone in the
center of the tabletop (as in Fig. 4).
Fig. 4. Talk-show miking with a PZM.
The results have been phenomenal! Not only has the PZM performed with signal clarity and strength
equal to a lavalier mic for all subjects around the table, but our guests have been able to just walk in,
sit down, and start their discussion without having to fuss about mic placement.
I heartily recommend this procedure for any and all studio interview recordings, both for audio and
television.
Jay J. Silvio
Illinois Bell TV Center
Chicago, IL
Harp and dulcimer miking
We just returned from performing at a music festival and the pickup on our Celtic harp and hammered
dulcimer left much to be desired. Can you or some of your readers suggest microphones and/or placement which could alleviate our problems? We suspect having our own microphones and doing our
own placement would help considerably with inexperienced sound engineers.
Secondly, we have a set of your Sound Grabbers and use them extensively for music recording and
sound reinforcement. We have also built some corner plexiglass baffles to be used with the microphones when we are providing sound reinforcement for our local school musicals. Our question is:
where and how should the Sound Grabber be placed in a three-walled boundary to maximize the
gain?
Gary Wakenhut
Erholengsland Personal Growth Center
Lakeview, MI
Reply:
For the harp, Gary, try one or two Crown GLM-100 miniature omnidirectional condenser microphones,
each in a GLM-SM Surface Mount. Tape them to the sound board, either on top or inside. Experiment
with position for the most natural tonal balance.
Try the above arrangement with the hammered dulcimer, too. As shown in Fig. 5, mount two GLMs
under the strings, on top of the sound board, spaced about 8" apart to pick up each half of the dulcimer equally.
Fig. 5. Dulcimer miking with a GLM-100.
Feedback is a real problem with the hammered dulcimer because it is such a quiet instrument. Miking
under the instrument helps gain-before-feedback, but it sounds unnatural. I asked for suggestions
from David James, a prominent local hammered-dulcimer player who has won several contests. He
told me of a solution devised by Malcolm Dalglish, the fine dulcimer player with Metamora.
Malcolm has used two C-ducer tape pickups mixed with top-mounted microphones. One C-ducer tape
goes under the bottom of the bass bridge; the other goes under the bottom of the treble bridge.
These are panned left and right for a pleasant, spacious effect. In addition, two cardioid mics are
placed on either side of the top, aiming toward the center, as in Fig. 6. A Crown CM-200 [now CM200a] cardioid condenser microphone is a good choice for this method.
Fig. 6. Stereo dulcimer miking.
For maximum acoustic gain with the Sound Grabber in a three-walled boundary, place the nose of the
microphone (containing the mic capsule) in the corner of all three boundaries. To do this, cut a slot in
the boundary as shown in Fig. 7 so that the Sound Grabber’s plate will slide under the boundary. If
possible, seal the slot to the Sound Grabber with clay or RTV Sealastic.
Fig. 7. Positioning a Sound Grabber in a corner boundary.
An angle of 135 degrees between boundaries has worked well. The bigger the boundaries, the more
directional is the microphone at low frequencies.
The impedance of the Sound Grabber is medium (1,600 ohms). Consequently, long cable runs (say,
over 50 feet) could result in hum pickup or high-frequency loss. You might be able to locate your mixer
near the stage to keep the mic extension cables short.
MOUNTING A GLM ON A FLOATING CEILING
Here is a tip from Crown’s Don Peterson for recording conversations in rooms with floating acoustictile ceilings. Some of these are research labs, interview rooms, teaching hospitals, police interrogation
rooms, etc.
1. Mount a GLM-SM Surface Mount on the metal ceiling grid.
2. Attach a GLM-100 microphone to the GLM-SM.
3. Run the cable up behind the tile into the ceiling, and to your mixer or recorder.
4. Using a small paint brush, paint the mic and its cable to match the ceiling. Take care not to paint
over the mic grille (the sound opening).
###
MIC MEMO
August, 1989
Bruce Bartlett, Editor
RECORDING VOCALS WITH PZMs
In the February ’89 issue of Recording Engineer/Producer, Dan Torchia interviewed Ed Seay about his
recording techniques. For the No.1 record “Cry, Cry, Cry,” Seay mounted a Crown PZM on a board
placed on a music stand. The female vocalist did overdubs with the PZM.
According to Seay, ‘She was singing into this board and she could not break up the PZM. It took a
little EQ to bring back the body of the sound. Because the mic is a hemispherical omni, it rejects
sound reflections from the control-room window.”
PZM OVERHEAD DRUM MIKING
In the June 1989 issue of Mix were some suggestions on miking drums overhead with PZMs. Gary
Platt, Vice President of Engineering at Platinum Recorders, had this to say:
“I like to put a pair of Crown PZMs on top [of the drums] by hanging them from the rafter or putting
them on a tall stand. It’s nice for a little high-end zip:
“I’ll take about 16kHz from [the PZM pickup] and roll off the rest. It works incredibly well.”
HOW TO MAKE BETTER STEREO RECORDINGS
The advent of digital audio, stereo television, and stereo film has sparked a renewed interest in truestereo microphone techniques. These methods use just two or three microphones to pick up a group
of sound sources as a whole.
During reproduction of a stereo recording, the listener can locate each instrument or instrumental
section between the stereo pair of speakers. The spaciousness of hall ambience is reproduced as
well.
A phantom image of each instrument is heard at various positions between the speakers. The position
of each image depends on the position of each real instrument around the microphone pair.
Stereo miking has several applications:
*Recording and broadcast of classical-music ensembles and soloists
*Stereo dialog and background ambience for film, video, and Electronic News Gathering (E.N.G.)
*Stereo pickup of piano, drums, and background vocals in pop-music recording
*Stereo sampling
*Television-audience miking
*Sound-effects recording
*Sports broadcasts.
An easy way to record in stereo is to use a stereo microphone. The ideal stereo microphone would
have these characteristics:
*Mono compatible. The frequency response is the same in stereo and mono.
*Insensitive to wind noise and mechanical vibrations
*Easy to aim
*Simple to use, without a mid-side (M-S) matrix box
*More portable than a spaced pair of microphones
*Inconspicuous (unlike a dummy head)
*Low cost - current models of M-S stereo mics cost $2,000 to $3,000.
*Compatible for headphones and loudspeakers. Coincident-pair stereo techniques have less stereo
spread over headphones than they do over speakers, making it difficult to judge imaging on location.
Further, the ideal stereo microphone would have:
*Sharp and accurate imaging
*An airy, warm, and spacious sense of ambience.
*Low off-axis coloration.
*Wide-range smooth response, low noise, and low distortion.
*Low interchannel phase shift at low frequencies for ease of record-cutting.
Crown has developed a new stereo microphone to meet all these requirements. The Crown SASS-P
[now SASS-P MKII] or Stereo Ambient Sampling System (Fig. 1) is a patented, stereo condenser
microphone using PZM technology. It was invented by Mike Billingsley, a Vermont recording engineer,
and was developed by Crown into a finished product.
Fig. 1. Crown SASS-P PZM stereo microphone.
The SASS-P uses two premium-quality Pressure Zone Microphones mounted on boundaries to make
each microphone directional. The capsules are spaced as far apart as your ears. A foam barrier
between the mic capsules reduces acoustic crosstalk which otherwise would cause phase cancellations in mono. Another Crown model, SASS-B [discontinued], is a similarly shaped stereo boundary
mount for Bruel & Kjaer 4006/4003 microphones, permitting 10 dB less noise.
For each channel, an omnidirectional microphone capsule is mounted on a boundary approximately 5"
square. The two boundaries are angled left and right of center. The sound diffraction of each boundary creates a directional polar pattern. At low frequencies up to about 800 Hz, the polar pattern is
omnidirectional, and becomes increasingly directional with frequency. The patterns aim left and right
of center, much like a coincident or near-coincident mic array.
The polar patterns of the boundaries and the spacing between capsules have been chosen to provide
natural perceived stereo imaging over loudspeakers and headphones. Carefully controlled listening
tests have shown that the SASS creates well-focused images, accurately placed and with no hole-inthe-middle.
A foam barrier/baffle between the capsules shapes the pickup angle of each capsule in the front and
limits overlap of the two sides at higher frequencies. Although the microphone capsules are spaced
apart, there is little phase cancellation when both channels are combined to mono because of the
shadowing effect of the baffle. Even though there are phase differences between channels, extreme
level differences caused by the baffle reduce phase cancellations in mono.
People who are familiar with PZMs might wonder whether the SASS has a good low-frequency response, since its boundaries are relatively small. The SASS has a flat response down to low frequencies; the usual 6-dB shelf does not occur. Here’s why: Since the capsules are omnidirectional below
500 Hz, their outputs at low frequencies are equal in level. These equal-level outputs are summed in
stereo listening, which causes a 3-dB rise in perceived level at low frequencies. This effectively counteracts 3 dB of the low-frequency shelf normally experienced with small boundaries.
In addition, when the microphone is used in a reverberant sound field, the effective low-frequency
level is boosted another 3 dB because the pattern is omni directional at low frequencies and unidirectional at high frequencies.
All of the low-frequency shelf is compensated, so the effective frequency response is uniform from 40
Hz to 18 kHz (Fig. 2). This can be proven in an A-B listening test by comparing the tonal balance of
the SASS to that of flat-response omnidirectional microphones. They sound tonally the same at low
frequencies.
Fig. 2. SASS-P Frequency response. Sound incidence perpendicular to boundary. Response up to 1 kHz is
the effective diffuse-field response with stereo listening.
The broad acceptance angle of each side’s capsule (125 degrees) picks up ambient sidewall and
ceiling reflections from the room, providing an airy perspective well suited to the reproduction of
acoustics in good halls and ambient environments. This pattern is consistent to well above and below
the microphone.
As a near-coincident array, the SASS forms stereo images by a combination of spacing, isolating, and
shaping the directional pattern of otherwise omni capsules to create time and spectral differences
between channels. Its stereo localization mechanism varies with frequency as described below:
*At low frequencies below 500 Hz, the SASS produces equal-level outputs from both channels, with
direction-dependent delay between channels.
*At frequencies between about 500Hz and 1500Hz, the stereo localization of the SASS is mainly due
to time or phase differences between channels.
*At mid frequencies (1.5 kHz to 3kHz), the localization of the SASS is due to a combination of time
and intensity differences.
*At high frequencies above 4 kHz, SASS localization is due mainly to intensity differences.
In other words, the localization mechanism of the SASS crosses over from low-frequency arrival-time
differences to high-frequency intensity differences in the vicinity of 2000 Hz. This is very close to the
mechanism used by the human hearing system, or by a dummy head.
Let’s run through the list of claimed advantages and explain how the SASS achieves each one:
*Mono compatible: The foam barrier between capsules prevents acoustic crosstalk which can cause
phase cancel lations in mono. As proof, record a person speaking in a normally reverberant room as
he or she walks around in front of the SASS. The reproduced tone quality will be the same in stereo or
mono.
*Low cost: The price is $799 for the SASS-B (without microphones) and $849 for the SASS-P (with
microphones).
*Compatible for headphones and loud speakers: The mic’s similarity to the human head assures
accurate headphone reproduction, and the spacing and polar patterns create accurateimaging over
loudspeakers as well.
*Insensitive to wind noise and mechanical vibrations: This is due to the highly damped, low-mass
diaphragms of the omni capsules.
*Easy to aim: Because of its shape, the SASS is intuitive to aim. And because it has a fixed position
when handheld, the SASS provides stable imaging.
*Simple to use, without a matrix box: Outputs are left and right channels. If desired, the user can
adjust the stereo spread in post-production with pan pots.
*More portable than a spaced array: It’s a single-point pickup.
*Inconspicuous (unlike a dummy head): The SASS looks mechanical rather than human.
*Sharp and accurate imaging: This claim is based on carefully controlled listening tests described in
Audio Engineering Society Preprint 2788 (A-i).
*An airy, warm, and spacious sense of ambience: This is due to the capsule spacing.
*Low off-axis coloration: This is due to the extremely small capsules in the PZM version, and the nose
cones in the B&K version which make the microphones more omnidirectional at high frequencies.
*Wide-range smooth response,low noise,and low distortion. The omni condenser capsules have an
extended response down to 20 Hz. According to TEF measurements, the response of both models is
wide-range and smooth. The measured self-noise of the SASS-P is 20.5 dBA; of the SASS-B is 11.5
dBA. Maximum SPL of the SASS-P is 150 dB SPL; of the SASS-B is 143 dB SPL.
*Low interchannel phase shift at low frequencies for ease of record-cutting: This is because the capsule spacing is only a few inches: a small fraction of a wavelength at low frequencies.
Included with the SASS are these items:
*carrying case
*windscreen
*auxiliary foam wind protectors [now discontinued]
*stand-thread adapter
*hand grip
*swivel mount
*phantom or internal-battery powering (SASS-P only) built-in low-cut switch (SASS-P only).
We hope that the SASS will become a useful new tool for the audio industry -especially for classical
recording and stereo ENG.
HOW TO HIDE A GLM IN THE CEILING
Crown’s Don Peterson invented a slick way to camouflage a GLM near a ceiling speaker baffle so that
the mic is invisible. Please refer to Fig. 3.
Fig. 3. Hiding a GLM near a speaker baffle.
1. Just outside the area covered by the speaker baffle, in the acoustic tile, cut a groove the same size
and depth as a GLM-100.
2. Lay a GLM-100 in the groove so that it is flush with the acoustic-tile ceiling.
3. To disguise the mic, paint it with Testors paint the same color as the tile, being careful not to get
any paint into or on the exposed capsule grille.
PLUG INTO YOUR ACOUSTIC GUITAR
Here’s a great suggestion from Doug Krehbiel, a musician in North Newton, Kansas. He plugs into his
acoustic guitar for convenient sound reinforcement. Figure 4 shows how.
Fig. 4. Connecting a GLM to an acoustic guitar.
Doug mikes his acoustic guitar with a GLM-100 mounted inside on the surface nearest the player,
facing the strings. Screwed into the end of his guitar is an end-pin jack. An end pin is a metal cylinder
to which you attach a guitar strap, and an end-pin jack is an end pin with a built-in 1/4" phone jack.
Inside the guitar, the GLM-100 plugs into the end-pin jack. When Doug wants to amplify his guitar, he
plugs a long custom cable into the end-pin jack, and connects the other end of the cable to a PA.
mixer unbalanced mic input.
The custom cable is shown in Fig. 5. One end plugs into the guitar’s end-pin jack; the other end plugs
into the mixer high-Z mic input. Power for the GLM is also applied at the mixer end from a 9V AC/DC
converter.
Fig. 5. Custom GLM cable for acoustic guitar.
Inside the guitar is a 1-foot cable (Fig. 5). One end is wired to the end-pin jack; the other end is wired
to a stereo phone plug. This plug connects to a stereo phone jack that is wired to the GLM-100.
For P.A., plug the GLM-100 into the end-pin jack and plug the long custom cable into the guitar and
PA. mixer. For recording other instruments, unplug the GLM from the end-pin jack, remove the GLM
from the guitar, and plug the GLM directly into the long custom cable.
Although the cable from guitar to mixer is long and unbalanced, Doug reports that it picks up no audible hum. This is because the GLM capsule is fairly low impedance (1.1kilohm). Doug also notes that
the GLM sounds great and has adequate gain for P.A.
###
MIC MEMO
December, 1989
Bruce Bartlett, Editor
SASS TABBED “FAB” AT NAB CONFAB
At the last NAB (National Association of Broadcasters) convention, the Crown SASS [now the SASSP MKII] was voted one of the top five new audio products out of 3000 products! Source:June 1989
Video Systems Magazine.
HOW TO LISTEN TO MUSCLES
Scott Robbins and Don Peterson, customer-service advisors on Crown microphones, described an
unusual request. Biomedical researchers at the University of Michigan and with Indiana Brace Co.
needed a microphone to pick up the sounds that muscles make.
The microphone was intended to be used by a physically handicapped person as a sensor to activate
an artificial hand. When the person wearing the artificial hand moves certain arm muscles, the microphone on the skin picks up the sound the muscles make. The resulting mic signal activates an artificial hand. This microphone pickup eliminates the need for implanted electrodes.
Muscle sounds are in the frequency range of 5 Hz to 25 Hz. So we recommended a microphone with
an excellent low-frequency response: the Crown GLM-100/E, which is a miniature omni condenser
microphone. By wiring it unbalanced without a transformer (Fig. 1), the user can obtain a response
that is flat down to very low frequencies (-3 dB at 20 Hz!). The mic will be encapsulated in silicone
rubber to prevent perspiration damage.
Fig. 1. GLM-100/E circuit diagram.
PZM PIANO MIKING
At a concert in North Africa, db Magazine journalist Ed Learned used a Crown PZM along with a
Sennheiser 421 for piano miking. He taped a Crown PZM-3lS [now PZM-30D] to the side of the piano
near the sound holes and cushioned the PZM with foam to prevent mechanical vibration. The lid was
on the short stick. He placed the 421 where the low and mid strings cross, aiming towards the hammers.
Learned reports that, with this method, the gain-before-feedback was adequate and the piano still had
“air.”
HOW TO REDUCE MIC NOISE
Want to reduce microphone hiss? Place the mic closer to the sound source.
Rex Garrett of SHOWORKS in Atlanta, Georgia, recorded a vocal and dulcimer with a Crown SASS-P
[now the SASS-P MKII].
The microphone was about 8 feet away at head height. He reports that the recorded stereo ambience
was “incredible.” But since the dulcimer is a quiet instrument, Rex had to raise his mixer gain to the
point where hiss just became audible.
We recommended that he place the mic closer - 3 to 4 feet - to increase the sound pressure level at
the microphone. This louder sound tends to override microphone and mixer noise. In addition, the
closer placement helps to reduce pickup of audience noise.
SASS APPLICATION NOTES
The following application suggestions are by the SASS inventor Michael Billingsley, who has used it in
the field and in the studio for several years. He also has recorded SASS stereo samples for
Synclavier.
The SASS is capable of seamless stereo at all distances beyond three feet. At closer distances, there
is some hole-in-the-middle effect (weak center image) because neither capsule can see a centered
sound source due to the center baffle.
In live-to-2-track recording, it’s best to make the final mic placement decisions while monitoring on
loudspeakers for more-accurate imaging.
If the correctly monitored stereo spread is excessive (because of close mic placement), run the SASS
signals through a stereo mixer with pan pots, and pan the two channels toward center until the stereo
spread is correct. This can be done during recording or post-production.
For a large musical ensemble, place the SASS 4 to 15 feet from the front row of musicians, angle it
down to aim at the performers (when raised), and raise it about 15 feet high on a microphone stand.
Closer placement sounds more edgy, detailed, and dry; farther placement sounds more distant,
blended, and reverberant. Try to find a spot where you hear a pleasing balance between the direct
sound from the ensemble and the hall ambience.
Because the SASS is quite sensitive to the sides as well as the front, closer placement will not be as
dry as with directional microphones. Hence, the SASS can be placed into an ensemble farther than is
ordinarily possible, providing great detail and spread if that is desired, without feeling forced or unnatural. The center of the sound image and the hall reverberation are still retained.
If you are recording a choir that is behind an orchestra, experiment with stand height to find the best
balance between the two sources. The strings project upward while the choir projects forward, so you
might find a better balance at, say, 9 feet high rather than 15 feet high.
For recording small ensembles, soloists, samples, or sound effects, the microphone need not be
raised above ear height.
When you mount the SASS on a moving vehicle, you should devise a shock-mount system to be used
under the microphone. Also be sure to use the windscreen, and enable the low-cut switch (or use lowcut filters in your mixer).
Often you can record news commentators without an auxiliary talent microphone. If the ambient noise
level makes this impractical, use a mixer to blend a talent microphone (panned to center) with the
SASS. The SASS will give a slight but noticeable boost to the appropriate side if the talent moves
away from frame center.
If the SASS is camera mounted, use the windscreen to subdue wind noise caused by camera movement.
The SASS can be mounted on fishpoles, floor stands, boom stands and tripods, in addition to the
handgrip.
When you record samples or sound effects for keyboard, drum-machine, or disk soundbank reproduction, any recorded ambience will be reproduced as part of the sample. For added future flexibility, you
may want to make several samples of one source at different distances to include the range of added
reverberance.
Off-center images can be reproduced accurately by sampling the sound source in the desired angular
position as perceived from stereo center. Recorded ambience will sharpen the image, but is not
necessary.
If angular positioning or ambience is included with the sample, and pitch shifting is anticipated, the
direction of the image and the size of the room will be affected by most pitch-changing algorithms. To
minimize these undesirable effects, try sampling at intervals of one-third octave or less.
Try to control the room ambience when looping so it is consistent before and after the sample (unless
reverbererant decay is desired as part of the sample).
When recording a moving sample or effect, experiment with distance between the microphone and the
closest pass of the sound source. The closer the SASS is to the path of the subject, the more rapidly
the image will pass the center point (almost hopping from one channel to the other). To achieve a
smooth side-to-side movement, you may need to increase the distance.
SASS AMPLIFIES BRASS IN OUTDOOR P.A. SYSTEM
At a summer outdoor concert in Elkhart, Indiana, a Crown SASS-P [now SASS-P MKII] was used to
pick up a brass ensemble for sound reinforcement. As the photos show, the SASS was placed a few
feet in front and above the ensemble. The microphone picked up an overall acoustical blend of the
performers and relayed it accurately to the audience.
Fig. 2. SASS carrying case.
Fig. 3. SASS picking up brass ensemble.
COMPARING LECTERN MICROPHONES
Scott Carpenter of Rainbow Sound, a church sound consultant in Huntsville, Alabama, compared the
Crown LM-200 Lectern Microphone [now the LM-201] to the competition. These are his unedited
comments:
LM-200
“The Crown LM-200 is the hands-down choice for this application. The most popular mic in use on
pulpits is the Audio-Technica AT 857-QM. We have used 857’s for many years with acceptable results. Since the introduction of the LM-200, we have begun to use it exclusively.
“The LM-200 has a solid steel tube and a base as rugged as a Sherman tank. Children can play stickshift with it all day without weakening the support. The AT gooseneck can become limp which makes
it difficult to keep in place. The tube on the LM-200 is longer than the AT’s, which gets the capsule
close to the source and improves gain-before-feedback. The supercardioid polar pattern further improves gain-before-feedback compared to the AT’s cardioid pattern.
“The integral pop filter on the LM-200 greatly reduces plosives which severely detract from a service.
Even with the foam windscreen installed on the AT, an over-emphasized “p” is reproduced as a small
explosion from the speaker cluster.
“The sound quality of the LM-200 has been highly acclaimed by all who have heard it. It has a wide
frequency response and an overall sound that is exceptionally faithful to the source. The sound is so
natural that soloists in one church preferred to sing through the pulpit mic rather than use the expensive Beyer handhelds they had.
“Probably the best feature of the LM-200 is its excellent isolation. The AT sends pulpit bumps and
kicks through the sound system which can be annoying and distracting. The LM-200 has isolation
comparable to a studio isobox [stand-mounted shock mount]. This substantially reduces mechanical
noises from the pulpit. This feature has made the LM-200 a favorite with pastors as well.
“In applications where the pastor moves or leans left-to-right and requires a wider field of pickup, the
Crown PCC-160 or the PCC-200 [discontinued] is optimum. The PCC-200 is simply a gated version of
the 160. Both mics are as small as a deck of cards, and exhibit excellent sonic characteristics. Although the isolation and gain-before-feedback are not quite as good as that of the LM-200, they are
superior to other mics we have tested for this application and work quite acceptably. They are also
excellent for use as an altar microphone and can be used on the floor to pick up large groups. This is
particularly useful for Christian drama.”
CHOIR-MIKING TECHNIQUES
Scott Carpenter also offered many tips on miking a choir with the GLM-200:
“The Crown GLM-200 is ideal for this application. It is less than half the size of a postage stamp,
which makes a group of them virtually invisible to the congregation. The Audio Technica 853 is the
most popular mic for this application. The AKG 460 is one of the most expensive.
“The GLM-200 has a hypercardioid pattern which provides higher gain-before-feedback than the AT.
Its wide frequency response and low off-axis coloration are closer to that of the AKG. They cost
roughly the same as the AT.
“Perhaps the neatest feature of the GLM-200 is that it can be mounted on a clear plastic stand from
the gound up. This eliminates all the scaffolding and overhead wiring as well as all the fishing line and
spider webs used to position the mics. Lexan corner molding is used for the stands. It is manufactured
by Tri-Guards Inc. and is available at your local Sherwin Williams store. The small 8-foot section sells
for under $4.00. The stands can be cut to the desired height and mounted to or near the choir rail (as
in Fig. 4). The mic itself can be mounted with hot-melt glue for permanent istallations, or taped to
allow removal.
Fig. 4. GLMs on clear plastic stands.
“The GLM-200’s can be removed and used in a similar fashion to mike a small orchestra or choir
during Christian dramas and special music presentations. This allows the music director to put the
choir where desired, and place the choir mics near the choir.
“The 200 can also be hidden in scenery and used for nearfield dialogue pickup. This extra flexibility,
which is impossible with fixed hanging mics, coupled with its outstanding performance, makes the
GLM-200 a clear winner for choirs.
“If for some reason the mics must be used hanging, such as for an exceptionally large choir, a coil of
small stiff wire around the end of the cable and the base of the mic will allow proper orientation and
positioning.”
MIKING A PIANO WITH A GLM-100
More tips from Scott Carpenter, this time on using a GLM-100 to mike a piano:
“An esteemed colleague in Atalanta told us about the excellent results he had obtained from using an
omnidirectional mic to pick up the piano. Because of feedback concerns, we had never considered the
use of an omni mic for live sound reinforcement. We try to be open-minded about innovation, so we
tried it and were amazed at the results.
“The Crown GLM-100 was the mic we used. It had much more even pickup of the different tones than
the cardioids we had been using. Experimentation with placement quickly yielded optimum placement
for the different instruments we tested. The mic works well on uprights, baby grands and grands. The
close placement coupled with the high output of a piano prevents problems with gain-before-feedback.
Even in applications where the piano was run hot through speaker-cluster monitors, feedback was not
a problem.
USING CM MICS FOR HANDHELD VOCALS
Finally, some more comments from Scott on Crown’s handheld microphones:
“The Crown CM-200 [now the CM-200A] is our microphone of choice for handheld vocals. Condenser
vocal mics typically exhibit better frequency and transient response than dynamics, as well as better
pattern control. The problem is that most condenser mics are cost-prohibitive. There are a few condensers with prices comparable to a good dynamic, available from manufacturers such as E.V., Audio
Technica, AKG, and Crown.
CM-200
“Suffice it to say that after playing with all of them, we felt that the Crown CM-200 was best in terms of
performance, durability, and price.
“Several churches have reinforced our opinion, since auditions of the CM-200 caused them to replace
their exisiting mics with Crowns.
“In extremely high-level applications, the CM-310 Differoid [now the CM-310A] provides the highest
level of gain-before-feedback we have heard from any mic anywhere.
HOW THE SASS PROVIDES GREAT STEREO
As we described last issue, the Crown SASS or Stereo Ambient Sampling System is a new stereo
microphone that provides very accurate and pinpointed stereo imaging. Figures 5 and 6 show two
models, SASS-P [now the SASS-P MKII] and SASS-B [discontinued] respectively. How do they work?
Fig. 5. SASS-P (rear).
Fig. 6. SASS-B (since discontinued).
At low frequencies, the SASS localizes images by arrival-time differences between channels. At high
frequencies, it localizes images by amplitude differences between channels. This is very close to the
mechanism used by the human hearing system, and for dummy-head recording.
Is there a theoretical basis for such a system? According to Gunther Theile of the I.R.T. (German
broadcast organization), the interchannel differences needed for best stereo are head-related. A
dummy head or similar system produces interchannel spectral and time differences, which Theile
claims are optimum for stereo.
He proposes a new theory of localization: the association model. It suggests that, when listening to
two stereo loudspeakers, we ignore our inieraural differences and instead use the speakers’
interchannel differences to localize images. (Reference: “On the Stereophonic Imaging of Natural
Spatial Perspective Via Loudspeakers:Theory”, by Gunther Theile (Institut fur Rundfunktechnik),
Perception of Reproduced Sound 1987, ISBN 87-982562-1-1.)
Since the SASS uses interchannel differences similar to those of the human head, it should provide
optimal stereo, based on Theile’s model of localization. According to listening tests described in Audio
Engineering Society preprint 2788 (A-I), the controlled polar patterns and head-sized spacing between
capsules create very well focused,natural stereo imaging with no hole-in-the-middle. The reproduction
of the sound field is precise and realistic.
###
MIC MEMO
March, 1990
Bruce Bartlett, Editor
INVISIBLE MICS SAVE THE DAY
How do you record an old-fashioned wedding with no microphones in sight? Try PZMs on the floor!
I was asked to record a wedding service and wedding music played by acoustic instruments. But this
wedding was different: It was an old-fashioned type with early-American music played by traditional
acoustic instruments. The bride did not want to see high-tech recording equipment distracting from the
old-time setting.
PZMs to the rescue. I was able to record all the wedding music in stereo, and the service itself, with
two PZM-30FS [now PZM-30D] microphones on the floor.
Figure 1 shows a typical layout. The musicians — playing hammered dulcimer, whistle, fiddles,
accordians, andboudhran — were on a 12' x 12' stage. The PZMs were placed about 3' apart on the
floor in front of the musicians.
Fig. 1. PZMs recording wedding music.
I had to change mic positions quickly for different musical ensembles, but it was easy to pick up the
PZMs and replace them in an intuitively correct spot.
For example, some of the music was performed by a singer who stood far in front of the other musicians. Since the PZMs were behind the singer, she could not be heard clearly in the recording. Before
the next number, I put one PZM in front of the musicians, and one in front of the singer. This was a
pickup of two mono sources rather than a stereo recording. It greatly improved the balance between
the singer and the backup band.
The PZMs also picked up the wedding service clearly. The preacher, bride and groom stood near the
PZMs at their feet.
I recorded on a Sony DAT, which came in handy because of its 2-hour nonstop recording time. I could
leave the recorder unattended much of the time and join the wedding festivities.
The sound quality was lively and natural. The PZMs picked up just enough crowd noise to convey the
feeling of celebration. All the audible spectrum was reproduced with realism, from the low thump of the
Irish drum to the delicate tinkle of the hammered dulcimer.
Problems cropped up, of course. Before the wedding I taped the PZMs to the wall in front of the musicians as an alternative pickup. But I heard a buzz in the monitored signal. The culprit was a dimmer
that faded the light over the stage. I couldn’t locate the dimmer, but I noticed that the hum field was
directional. When the mic cables were horizontal, the buzz stopped. So I finally laid the PZMs on the
floor.
After the wedding, back at home, I ran the DAT tape through a mixing console to EQ it. In quiet passages, a little buzz remained which I removed with a 4 dB cut at 10 kHz. Several of the songs had no
low-frequency content, so I rolled off the low end on these songs to reduce noise. The console signal
fed a cassette deck to make cassette copies, which became a prized momento for the bride and
groom.
I doubt that I could have done this recording as well - and as inconspicuously - without PZMs.
GLM VIOLIN MIKING
It’s very difficult to reinforce a quiet instrument, such as a violin, without feedback. One fiddle player
tried mounting a GLM-l00 omni and a GLM-200 hypercardioid next to an f-hole, but she had feedback
problems onstage. The solution was to place a GLM-100 inside the violin (through the f-hole). Then
there was plenty of gain-before-feedback.
STEREO LOCATION RECORDING WITH THE SASS
by Mike Billingsley (BACKTRACKS Location Recording)
Did you ever question the “real-ness” of soundtrack stereo?
There is a barebones method for lending extraordinary realism to a stereo production without having
to string out a half-dozen talent mics,or putting a suitcase full of unidirectional mics in front of every
instrument in the orchestra or every kid in the choir.
By adding one high-quality stereo microphone to your setup, with maybe some primary talent mics
plus a 4-into-2 or 6-into-2 location portable mixer, a very different (and exciting) stereo soundtrack can
be mixed live on location, with very little post-production sweetening required.
I’m not talking about the usual mid-side stereo or “stereo shotgun,” which use only interchannel intensity differences to create the right-left image.
Instead, I have fortunately been able to make use of a new microphone which establishes sound
location by time delays in addition to intensity differences - by spacing the two mic capsules about the
width of a human head while baffling the space between them with acoustic absorbing foam.
The audible effect of this microphone, Crown International’s SASS, is quite remarkable.
By itself, in the field, the SASS can record direct to a portable cassette, reel-to-reel, VTR or DAT
machine for extraordinarily detailed stereo imaging. The spaced mic capsules allow the mind of the
listener to accurately recreate the position of each cricket in a field, individual drops of rain on leaves
in a forest, or each of many footsteps or murmurs in a midday crowd.
As a wild-sound recording microphone, or as an ambient mic to catch surrounding and background
action, the SASS is unparalleled. I have used it to record hurricane surf, beaver ponds at dawn, traffic,
fairs, restaurants, wind in forests, splashing bathers and rattling machinery.
The author collecting wild sounds of chain saws and skidders for the soundtrack of “Patrick’s Walk.”
In addition (as music recordists might expect) the SASS makes an excellent primary mic for the recording of symphonic concerts, choirs, percussion ensembles and acoustic jazz and folk - not to
mention probably the best image of an acoustic piano going.
For scripted drama, sports, audience participation shows, and documentaries, the SASS establishes a
true stereo presence around your primary action or characters - the acoustic “ambience” that surrounds the event on screen - which cannot be created any other way. A dozen or more panned mics
through a giant console just fake it.
The technique is simple. As the SASS follows the camera angle, either by being panned with the
camera by the soundperson or by being mounted on the camera, it gives a detailed, left-to-right image
of the acoustic environment pictured.
All that remains is to pan any talent mics (and they may not be necessary) to the position in the stereo
perspective that matches where they are heard by the SASS,and then to bring up that mic on the
portable mixer until it is just audible enough to lend the needed clarity to speech.
In a pinch, a single talent mic (or even two) can be center-panned even if there is some on-camera
movement. The SASS imaging is so precise that, within certain readily apparent limits, it will “pull” a
mono-centered mic in the mix toward the side where it “hears” that talent position - giving the benefit
of that additional mic without having to do “follow-panning.”
This also works in a live concert situation for pop music. In this case, the portable mixer can be used
to mix in the mono public-address feed (pre-EQ and post-fader) with the SASS stereo image - putting
the SASS abovethe musicians on stage so there’s a good spread from left to right. Again,just bring up
the mono feed a tad to give the clarity needed for vocals and instrument solos.
All-in-all, the SASS is an incredibly versatile microphone, extremely useful to me in almost all my
work. Its other virtues are a phenomenal low-end (extremely useful for sound effects recording), an
even frequency response without obnoxious peaks, no proximity effect (the capsules are omnis) and,
for its size, extremely light weight (slightly over a pound).
I use the SASS-P [now the SASS-P MKII] with on-board choice of batteries or phantom for all my
location work, and the SASS-B [discontinued] (which acts as a frame for a pair of Bruel & Kjaer studio
mics) for my remotes and studio work with musicians.
The SASS represents a trouble-free method to introduce breathtakingly real stereo for producers on a
tight budget with a small crew, and allows some confidence in productions where, until now, there
were usually only headaches.
Mike Billingsley is producer/owner at BACKTRACKS Location Recording in Monipelier, VT... specializing in location and remote recording of digital sound. BACKTRACKS has a digital post-production
editing room and releases sound effects, samples, and acoustic music albums, under the Straight
Arrow Recordings label.
LETTERS FROM CROWN MICROPHONE USERS
PZM chest mount for drum pickup
I mike my whole set of drums, indoors or out, with great results using only one PZM-30FS [now the
PZM-30D].
I cut out a 7"x8" 16-gauge aluminum plate with one hole in each corner for attaching two 12" elastic
straps (Fig. 2). One end of each strap is tied to the plate, stretched around the body or neck, and
attached to the other side of the plate with a small hook made out of coat-hanger wire.
I duct-tape the PZM around the plate borders to secure it to the “chest mount.” This effectively puts
the PZM right in the middle of things.
It clearly picks up all toms, snare, bass drum, and cymbals. In small clubs, or on large outdoor
stages, one PZM beats ten regular mics for convenience any day in my book. Thanks!
Chris J. Altizer, Barboursville, West Virginia
Fig. 2. PZM chest-plate mic.
###
MIC MEMO
June, 1990
Bruce Bartlett, Editor
GET A GREAT DRUM SOUND WITH THE SASS
At a recent recording session, the Crown SASS-P PZM stereo microphone helped to create an awesome drum sound.
The artist being recorded was Zoro, the exciting drummer with the Lenny Kravitz group (recently on
tour with Tom Petty). Zoro and keyboardist Kenneth Crouch set up in a house near Crown to record
segments for an upcoming SASS demo CD.
Zoro
Tom Edmonds, who has done sound for such acts as Meafloaf and Miami Sound Machine, was engineer/producer. Within five minutes, he came up with a sound that, he said, “would have taken hours in
the studio to create.”
Zoro’s drums were placed in a brick-lined reverberant room in the home of Clay and Gerry Barclay. In
addition to offering the use of their home for the session, they provided a Biamp mixer, Crown MicroTech 1200 power amp, and Community monitor speakers.
Edmonds mounted a SASS-P close to the drum set, in front, just above the snare-drum height and
below the cymbals. He used an AKG D-112 in the kick. Edmonds also placed two SASS-P microphones about 25 feet out in the room, spread far left and right, for ambience pickup (Fig. 1).
Fig. 1. Drum and ambience miking with SASS mics.
The result was a powerful sound, close but spacious. Stereo imaging and spread were outstanding,
and transient attacks were clean. Zoro said that his drum and cymbals sounded more realistic with the
SASS than with any recording he had heard before.
It was easy to vary the drum sound by bringing the ambience mics up or down. With just the close-up
SASS on, the sound was tight and detailed. With the ambience mics up, the sound was “heavy metal.”
All this with NO signal processors in use!
Ken Crouch expertly played a Clavinet and a Korg M-1, which were recorded direct. All the drum mics
and keyboards were mixed live to a Sony DAT recorder.
Dan Fye of DAF Studios helped set up the drums and assisted with the session, while Zoro’s wife
Andrea Tipon added good vibes.
Edmonds calls the SASS his “secret weapon.” He plans to take it on tour with Zoro and use it for
future recording sessions. In fact, the SASS appeared on the Feb.28 Arsenio Hall show, where the
Lenny Kravitz band played “Let Love Rule” and “Mr. Cab Driver.”
We suggest you try the SASS too, and see if you aren’t amazed at how easily you can get a clean,
larger-than-life drum sound.
Zoro’s drum set miked with the SASS-P.
Zoro’s drum set miked with the SASS-P.
PZMs ON RECORDS
In a recording session with Jason and the Scorchers for A&M Records, engineer Justin Niebank
placed a PZM behind the guitar amp cabinet. It was a strange placement, but he liked the sound.
For Siouxsie and the Banshees’ 10th LP, producer Mike Hedges used two PZMs on the ceiling over
the drums.
Here’s an unusual miking setup: When recording the Pogues, engineer Chris Dickie tried a PZM on a
flight case behind the drum kit, and said it “sounded great.”
Source: Feb. ’89 Stage and Studio.
HOW TO RECORD GROUP DISCUSSIONS
Dr. Cynthia Cohen, a researcher with a company called Verdictsuccess, uses a Sound Grabber to
record group discussions. She videotapes them with a camera behind a one-way mirror, while the
Sound Grabber picks up the conversation.
To ensure that the AA battery for the Sound Grabber will work, she replaces it just before each taping
session.
At Crown we experimented with several placements of the Sound Grabber to pick up a person speaking in a small room. This is what you’ll hear with the mic in different positions:
*On the floor: relatively bassy and boomy.
*On a table: less bassy.
*On a wall: clearest sound.
Apparently, the wall makes the Sound Grabber like a directional mic aiming at the person. If the
Sound Grabber is on the floor, it’s directional, but aims up - not at the person speaking. The wall
placement gives a higher ratio of direct-to-reverberant sound, which aids clarity.
“S” sounds radiate straight ahead from the mouth, but not so well to the sides or rear. For this reason,
it’s important to place the mic so that it can “see” everyone’s mouth. If the mic is behind a person’s
head, the voice becomes muffled or weak in “S” sounds.
To connect the microphone to a remote cameorder’s mic jack, you need a microphone extension
cable. Use oneconductor shielded mic cable with an 1/8" phone jack on one end and an 1/8" phone
plug on the other.
How long can this cable be? At Crown we put a 60-foot extension cable on a Sound Grabber and
recorded a person speaking. It sounded clean. The microphone impedance is fairly low - 1600 ohms so you can add at least a 60-foot extension cable to the Sound Grabber without hum pickup or loss of
clarity.
REPORT FROM GENERAL TELEVISION NETWORK ON THE SASS
Gary Pillon, a sound engineer at General Television Network, used a SASS-P [now the SASS-P MKII]
to record a 45-piece vocal group and a pipe organ. The SASS was run through two Boulder low-noise
mic preamps into a DAT. Gary compared the SASS to conventional condenser mics, and to a PZM
wedge (2’x2' plex boundaries in a “V”).
Pillon says that the SASS reproduction is “phenomenal,” “uncanny,” “musical-sounding,” and “pleasant.” He is “very, very impressed.”
The SASS, he says, “is its own animal.” It sounds neither like the wedge nor the conventional mics,
but sounds more like the conventional mics than the wedge. It gives a close perspective but with
plenty of room ambience... “Just right there. The wedge has a little more air, but the SASS has a
better low end.”
According to Pillon, SASS imaging is excellent, and gives the impression of a three-dimensional
sound space. He even hears a sense of front/back (sound sources behind the head) when wearing
headphones.
He likes the frequency balance. “It has plenty of bottom... it’s nice to hear that without resorting to
EQ.” The noise floor is sufficiently low for his work. Unlike with some other microphones, it was easy
to hear an absolute polarity reversal with the SASS.
He also likes how the microphone is lightweight, and noticed no pickup of hand vibration through the
hand grip.
Pillon plans to make a CD of this recording.
RECORDING BONES WEST WITH THE SASS
At the recent NAMM show in Anaheim Crown engineers used a SASS-P [now the SASS-P MKII] to
record the big band, Bones West. As the photos show, the mic was about 8 feet high and 20 feet
back. The result was a realistic recording of the event. The kick-drum reproduction was particulary
deep and impressive.
SASS recording Bones West. Mic Dept. manager Tom Lininger monitors the recording.
CONQUERING FEEDBACK WHEN MIKING A CONFERENCE
A Crown microphone user had feedback problems with PZMs when picking up a conference. As
Figure2 shows, the conference tables were arranged in a “U” about 28 feet wide. Sixteen PZM-2ORG
[now PZM-20R] microphones were mounted in the ceiling every 4 1/2 feet apart over the tables.
These mics were amplified through 20 ceiling speakers.
Fig. 2. PZMs over U-shaped table.
Gain-before-feedback was inadequate for several reasons:
*Too many mics were used. The more open mics, the poorer the gain-before-feedback.
*The mics were too far from the talkers. The farther the mics, the poorer the gain-before-feedback.
*The 2ORG is omnidirectional. An omnidirectional mic has poorer gain-before-feedback than a cardioid mic.
*The ceiling speakers were close to the microphones. The closer a speaker is to a mic, the poorer the
gain-before-feedback.
So, we recommended that the user follow these suggestions:
*Cut the number of mics in half.
*Use an automatic mixer.
*Put the mics on the table.
*Use directional boundary mics (PCC-160).
We also suggested that the user configure the automatic mixer so that, when a mic gated on, loudspeakers near that mic were made to gate off.
When all these suggestions were followed, the gain-before-feedback improved dramatically.
MEATLOAF’S SOUND ENGINEER ON CROWN MlCS
Jim Stanforth, sound engineer on the Meafloaf tour, has this to say about Crown microphones:“CM100: [discontinued] Excellent handling noise (or lack thereof). Really smooth sounding, although we
missed and had to EQ in proximity effect [up-close bass boost] found in cardioids. Monitor levels were
a bit of a problem with wedges.
“GLM-100: Marvelous in percussion such as octobans, timbales, single-head toms (from inside).
Heard a bit too much reflection from front head on kick drums. Sounded like a PZM-31S placed in the
bottom (or anywhere on the shell) of the drum.
“GLM-200: Fantastic!! Great success in kick drum (very smooth and clean). Worked well on the whole
drum kit. The least EQ ever used on a kick drum. Produced a solid, clean sound.
See Figure 3 below for Jim’s kick-drum miking setup. Although the GLM-200 worked well in this application, readers should note that the GLM-100 has a better low-frequency response and higher overload capability than the GLM-200. Try them both on kick drum -Ed.
Fig. 3. Mount for GLM-200 miking a kick drum.
PZMs FOR AMBIENCE AND INTERVIEWS
At a taping of a television concert in Sudan, sound engineer Ed Learned placed a Crown PZM on a
“flat” or scenic partition behind the Jay Haggard Quintet to pick up ambience.
Learned reports, “After the music was done, we cut a short interview with Jay. I miked the interview
with my PZM placed on the floor in front of the seated subjects. It worked fine, with the added advantage of being invisible to the camera. PZMs were new to Sudan; the engineers were quite amazed by
their quality and versatility.”
Source: Jan/Feb ’90 db Magazine.
GLMs AT THE GRAMMYS
At the Grammy Awards on November 24, 1989, sax player Clarence Clemens used a GLM-100 in a
GLM-HM Horn Mount to pick up his saxophone. He is a member of the band, Living Legends.
AMBIENT MICS INCREASE REALISM
Scott Carpenter, a church sound consultant in Huntsville, Alabama, has this to say about using Crown
microphones for ambient miking:
“Recordings and remote feeds of a worship service sound much more realistic when a couple of
ambient mics are mixed into them. There are a number of sounds during a service, such as congregational singing, that simply are not picked up through the reinforcement mics.
“Ambient mics give the listener a much better sense of ‘being there.’ The optimum mics depend on the
size and acoustics of the room, but some experimentation with GLM 100s and 200s, PZMs, and the
PCC-160 will quickly yield good results.”
GLM-200 CHURCH APPLICATIONS
Scott Carpenter has other comments on Crown microphones:
“In our opinion, the GLM-200 is the workhorse of the Crown line. In churches with instruments on
stage, it is completely versatile.
*It can be taped facing the head of each drum in a kit, and extended over a kit for cymbals.
*It can be taped to the face of a guitar amplifier with excellent results.
*A pair can be placed on either side of the Leslie rotating speaker in a Hammond B-3. This stereo
pickup will produce exhilarating results if the house system is a stereo split cluster type. You can pick
up the pedals with a direct box.
*They also work well taped to a stand for acoustic-guitar pickup.
*You can stick one on the wall in the baptistry and pick up not only the words, but also the water
splashing.
*They can be easily taped to wind instruments and have the capacity to reproduce their high output
without distortion.
“We normally specify extra GLM-200s in our systems, and are pleased to see that they are rarely on
the shelf.
“You can place one GLM-100 omni inside an upright piano, close the lid, and pick up all the notes
without feedback.”
RECORDING A BRASS QUARTET WITH GLMs
Recently a local brass quartet asked to be recorded for an audition tape. I attached a GLM-HM Horn
Mount [discontinued] to the bell of each instrument: first trumpet, second trumpet, French horn, and
baritone. Onto each Horn Mount was clipped a GLM-100 omni mini mic. Each GLM was placed a little
off-axis of each horn, and as far from the bell as the Horn Mount would allow.
The performers liked this style of miking because they could move around. They didn’t have to keep
their instruments aimed at a microphone.
The resulting sound from such close miking was a little bright and thin. To compensate, I applied this
equalization:
Trumpets: +3 dB at 175 Hz, -3 dB at 3 kHz and 10 kHz.
Baritone: +3 dB at 100 Hz, -3 dB at 10 kHz.
French horn: -12 dB at 10 kHz (to reduce breath noise).
LETTERS FROM CROWN MICROPHONE USERS
Preventing phase cancellations with the SASS
I’m using a SASS-P [now the SASS-P MKII] to pick up a performance of actors on stage. Even though
the SASS uses PZMs, I’m hearing phase cancellations from floor reflections. How can I prevent this?
Reply:
Try placing the SASS even with the stage floor, out front, as shown in Fig. 4. In this position, the
microphone can “hear” the sound sources, but cannot hear any sound reflections from the stage.
Fig. 4. SASS placement near stage edge.
If the microphone is too low, below the stage floor level, it can’t see the actors so the sound may be
dull. If the mic is too high, it will pick up floor reflections that can cause phase cancellations.
Any PZM eliminates phase cancellations from the boundary it is nearest to, but not from distant
boundaries. If a PZM is raised above a floor, you need to place it carefully to prevent phase interference from the floor reflections.
Ken Wahrenbrock update
Ken Wahrenbrock developed the first commercial PZM and invented several PZM multiple-boundary
arrays. This recent letter from Ken shows that he is still actively promotmg the PZM concept:
“I had to do a quickie recording of a theater organ concert for a young blind organist and used my
SONY TCD-5 with a stereo PZM like the one Gary Pillon made. [This microphone is made of two
small plexiglass pyramids angled apart, with PZM capsules at the apexes, ear spaced. See the Crown
Boundary Microphone Application Guide for details, available free from Crown - Ed.] I recorded from
about 3/4 back in the auditorium at San Gabriel and got some good cassettes with surprisingly good
bass for the small boundaries.
“La Mirada Theater is using Crown PCC-160s [supercardioid boundary mics] across the stage for a
play.
“Several junior-high and high schools around this area are using PZM 2-1/2 x 12" units with PZM-6S
[now PZM-6D] cantilevers. [A PZM 2-1/2 is a V-shaped plexiglass boundary that sits on the floor. The
PZM capsule is mounted in the apex of the 135-degree angle. -Ed.]
“I’m still finding that the 2260s [plexiglass wedge, 22" long, 60-degree angle] are providing pulpit and
lectern coverage at churches around here. The staff likes the freedom from having to [speak into] a
mic on a gooseneck.
“Next June at the Annual Conference in Redlands, we are going to use two of the new Crown podium
mics [LM-200] [now the LM-201] for the lectern and Bishop. The video people want a smaller [microphone] than my redundant PZM hand-held with 2 1/2"-diameter heads. Wish I could use 2260s, but
the parameters won’t allow it and give me enough gain-before-feedback in the reverberant house.
“The Mic Memo continues to be an excellent update on miking, with the practical input from those who
are using them.”
NOW AVAILABLE: CROWN MICROPHONE SLIDE RULE
If there’s any microphone spec that’s confusing, it’s sensitivity. How do you compare two microphones
rated in different ways? One spec might be in dBV per microbar; another might be in millivolts per
pascal.
There’s help. Crown is offering a low-cost, fiberboard slide rule that lets you easily convert from one
microphone-sensitivity specification to another. It also helps you calculate the microphone output
voltage for a given input sound pressure level.
All the sensitivity ratings are here: open-circuit sensitivity, power sensitivity, and EIA rating. If you
know one sensitivity spec and the microphone impedance, the slide rule calculates the rest.
Attractive and easy to use, the slide rule also includes a polar pattern chart which describes the characteristics of each pattern.
You can order the Crown Microphone Sensitivity Slide Rule for $5.00 (check or money order) directly
from Crown Intemational, P.O. Box 1000, Elkhart, IN 46515-1000.
###
MIC MEMO
September, 1990
Bruce Bartlett, Editor
GENTLEMEN, START YOUR ENGINES!
Mrs. Hulman starting the race.
Those famous words that began the Indy 500 auto race were heard over TV, radio, and the track P.A.
system — thanks to a unique Crown microphone with three mic capsules in one grille. Mrs. Holman,
owner of the Indianapolis 500 Motor Speedway, was picked up by this microphone when she started
the race.
Crown engineers modified a CM-200 microphone so that three miniature mic capsules fit inside the
grille. Each of these capsules fed a separate electronics interface. The three interfaces had isolated
outputs, preventing ground loops between the three feeds.
One feed went to ABC Sports for their TV broadcast of the Indianapolis 500 auto race; another feed
went to the Indy 500 Motor Speedway radio network, and a third went to the track P.A. system.
CM-230 Tridundant microphone in use.
Why not use three microphones instead? The speedway’s technical people wanted a cleaner television shot of Mrs. Holman. Putting three mic capsules in a single microphone was the solution. Three
separate capsules, with their electronics, made a highly reliable “tridundant” system. One capsule’s
signal went to an Altec mixer, then to a distribution amplifier providing feeds for other users.
Crown microphones produced audio for several other applications at the race:
*The track P.A. annoucer used a CM-310 Differoid. He sat in the stands while announcing, and
needed a microphone that didn’t feed back or pick up leakage from the race track.
*Two PZMs in plexiglass wedges picked up the Purdue Band playing “Back Home in Indiana.”
*A PCC-160 on the pavement picked up the race cars starting and driving away. This mic fed the
Motor Speedway radio network.
*A PZM on the track wall picked up the cars for ABC Sports.
*The person who introduced Mrs. Holman used a CM-200 cardioid condenser microphone, as did Jim
Nabors and others when they sang.
*ABC Sports hung a SASS-P PZM stereo microphone over the audience to pick up the race in stereo.
SASS clamped to fence.
*The Motor Speedway radio network used a SASS-P for the same purpose. This microphone was
mounted on a fence rail using an adapter built by John Royer, head of audio for the race track. His
adapter matched the 5/8"-27 thread in the SASS swivel mount to a 3/4" pipe. The pipe was clamped
to the fence by two angle irons.
*The radio network hung a SASS-P over the finish line.
Other Crown products contributed to audio at the race. Four Crown Macro-Tech 10,000 amplifiers
powered the track P.A. system. This is the biggest P.A. in the world, employing 460 speakers. Since
each amplifier carried one-fourth the load, the amplifiers were practically “loafing” while in use.
A Crown IQ-2000 System connected to a MacIntosh computer was used to monitor the MT-10K’s and
three Comm-Tech CT-400’s. The CT-400’s provided P.A. in the new Tower Terrace Suites, 1/4 mile
away from the computer. The IQ System was used to set input gains, and to monitor output levels
and temperature of all the amplifiers.
We’re proud that the Indianapolis 500 Motor Speedway relies exclusively on Crown for microphones
and amplification. We’ll be back the next time those intrepid gentlemen start their engines.
SASS USED IN HUNT FOR RED OCTOBER
Check out the Sept. ’90 of Mix magazine for an article on audio for the movie Hunt for Red October.
A SASS-P up sounds inside the submarine interior which added greatly to the realism of the film.
More in the next issue!
PZM WIRING
Many users have PZMs that they want to connect to a wireless transmitter. The table describes how
to connect each model.
Old PZMs
30GP, 31FS:
Connect pin 2 or orange to audio in.
Connect pin 3 or red to B+.
Connect pin or grey to ground.
6LP, 6FS:
Connect pin 2 or white to audio in.
Connect pin 3 or red to B+.
Connect pin 1 or black and shield to ground.
New PZMs
First unsolder the leads from the printed circuit board.
30R, 30F:
Connect orange to audio in.
Connect red to B+.
Connect grey to ground.
6R, 6F:
Connect white to audio in.
Connect red to B+.
Connect shield to ground.
[The current PZM models, PZM-30D and PZM-6D, need phantom power so they can’t be connected
directly to a transmitter.]
LIST OF SASS USERS EXPANDS
The University of Michigan has purchased a SASS-P PZM Stereo Microphone for making stereo
recordings of the Wolverine Marching Band.
Three reviews of the SASS, all highly favorable, can be found in the first issue of EQ magazine, April
1990 Mix, and April 1990 Electronic Musician.
MIKING A FLUTE WITH A GLM-100/E
Monte Stewart, a flutist in Modesto, California, uses a broom clip from a hardware store as a flute clip
for a GLM-100/E mini mic. He glues felt inside the broom clip to prevent marring the flute’s finish, and
traps the mic cable under the clip.
THUNDERING MICROPHONES, BATMAN!
VROOM! In the movie Days of Thunder starring Tom Cruise, Crown PZM and SASS mics captured
sound effects in the racecar scenes.
A SASS-P inside the car picked up ambience in stereo. One PZM-30R was mounted inside the
engine compartment, and another was mounted outside the car to pick up the slipstream and passing
cars.
In spite of the high sound pressure levels, the mics provided clean sound with thunderous low frequencies.
NEW PRODUCTS
Newly introduced from Crown is the LM-200a, a lower-noise version of the LM-200 Lectern Microphone. The LM-200a is nearly identical in performance and appearance to the LM-200, yet has several dB less self-noise. Another model, LM-190a, is the same but 3 inches shorter.
LM-200a
The Crown Microphone Application Guide and the Crown Boundary Mic Application Guide suggest
how to choose and use Crown microphones effectively. You’ll find suggestions for almost any miking
application, from a conference to a full orchestra. The Boundary Guide also explains how boundaries
and boundary microphones work. Both guides are available free from Crown.
The SASS-P has been upgraded with new hum-shielded transformers.
The GLM-CH is a choir hanger for GLM microphones. This wire-frame accessory makes it easy to
hang a GLM over a choir with correct orientation. You can thread fishline through the tiny pipe or
crossbar on the hanger, and attach the line to the sidewalls. This guy wire stabilizes the microphones.
The PZM line has been trimmed: All the PZM models are now available in black only, and come in
colorful, contemporary packaging. The list below compares the old and new model numbers:
OLD………………………...NEW
PZM-30RB, 30RG ………..PZM-30R……..[1998: PZM-30D]
PZM-30FS ………………. .PZM-30F……..[1998: PZM-30D]
PZM-6RB, 6RG……………PZM-6R………[1998: PZM-6D]
PZM-6FS…………………..PZM-6F……….[1998: PZM-6D]
INCONSPICUOUS, NATURAL CHOIR MIKING
Need to mike a church choir invisibly? Try the new Crown CM-30. It’s a tiny, supercardioid condenser
microphone on a 30-foot cable. The CM-30 is precisely designed for inconspicuous overhead miking
of
*Choirs
*Conference tables
*Theater stages
*Orchestra sections
*Audience reaction
CM-30
Installation is hassle-free, thanks to a unique ceiling-mounted electronics interface. This is a small
circuit board on a plate which mounts in a standard electrical box on the ceiling. The interface has
two functions: (1) It converts phantom power to a lower voltage for the microphone capsule, and (2) it
converts the medium-impedance unbalanced mic signal to low-Z balanced.
The interface is easy to install, and no connectors are needed. Simply attach the mic cable to the
interface by screw terminals, and run another mic cable from the interface output screw terminals to
your mixer. Your mixer provides phantom power for the microphone.
Choir miking
You can pick up a choir with no microphones in sight. Field-tested mic placements for choir sound
reinforcement are described in the data sheet.
When you place a microphone over a choir, the mic misses the sibilant sounds which project forward.
So a mic with a flat response can sound dull when placed overhead. To compensate for this, the CM30 has an emphasized high-frequency response. The result is a clear, natural sound.
Mic cables can lose their orientation as the mic cable uncoils over time, or the mics can swing back
and forth in a breeze. You need a way to hold the mics in position. For this purpose, the CM-30 has a
unique built-in hanger which comes with a tiny crossbar or pipe. You thread a fish line or black thread
through this pipe and attach the line to the side walls. This guy wire keeps the capsules oriented
straight ahead.
The hanger inserts into the mic housing and is held in place by a set screw. There’s no bulky, distracting coil of wire around the mic.
Conference table
Suppose you want to pick up a conference-table discussion, but your client doesn’t want any microphones on the table. Just hang one or more CM-30s over the table.
Theater stage miking
Use the CM-30 to pick up dialog that the front mics don’t get. Hang it overhead by its 30-foot cable.
It’s so small, it’s invisible to the audience, so you can hang it close to the actors. (Just watch out for
sets!)
You can hang the CM-30 straight down over the actors’ heads, or hang it in front of the actors at an
angle to better pick up sibilant sounds.
Orchestra and audience
If you record live concerts, the CM-30 lets you spot-mike sections of the ensemble without distracting
from the performance. The microphone also works great for miking audience reaction.
Specs
The CM-30 offers lower self-noise and deeper low-frequency response than the GLM-200 mini
hypercardioid microphone. Self-noise in the CM-30 is only 28 dBA, while frequency response is
smooth from 40 Hz to 20 kHz. The CM-30’s supercardioid polar pattern rejects feedback and background noise.
Altogether, it’s a top-performing mic that doesn’t get in the way.
ELEGANT LECTERN MIKING
If you need a quiet gooseneck microphone that looks great, the new Crown LM-300 is for you [now
the LM-301A.] It’s a sleek, black miniature gooseneck mic designed for use on lecterns, pulpits, judicial benches, and witness stands.
LM-300
This streamlined, classy-looking model flexes only near its base. Most of the gooseneck arm is a
slender pipe, so the mic retains its elegant shape after repeated adjustments. Electronics are selfcontained in a slender cylinder at the end of the gooseneck arm.
Thanks to its supercardioid pickup pattern, the LM-300 greatly reduces feedback, and its flat response
assures natural-sounding reproduction of the voice.
We’ve included a foam pop filter to lessen breath pops. You can purchase an optional metal grille
which locks on permanently. Another optional accessory is the LM-300SM lockable shock mount,
which reduces table thumps, handling noise, and theft.
The LM-300 is an economical alternative to the Crown LM-200a, which uses a ball-and-socket swivel
mount.
PREVENT GLM CLIPPING
A Crown microphone user noted a clipping distortion problem with GLM-100/E microphones when
they were used on horns, and powered by a Nady 650 wireless transmitter. Here’s one solution:
The GLM-100/E should connect to the high-impedance transmitter input. If the mic is overdriving the
transmitter, connect a resistive pad between the mic and transmitter, such as shown in Figure 1.
Fig. 1. GLM pad.
According to the GLM-100/E data sheet, the GLM-100/E can handle 120 dB SPL with a unipolar
supply such as provided by the Nady transmitter. But according to Crown’s measurements, a trumpet
can produce up to 154 dB SPL at 6 inches. So it’s likely that the trumpet is clipping the GLM.
However, with a bipolar supply, the GLM-100/E can handle 150 dB SPL at 3% THD. If the horn player
doesn’t play extremely loudly, the GLM-100/E should reproduce the signal without clipping. (In fact,
the Mic Memo editor has recorded a brass quartet with GLM-100’s attached to the bells of the horns,
with no audible distortion.)
If you can tolerate using an outboard box for bipolar powering, you should be able to pick up the horns
without distortion. The powering circuit is shown in Figure 2.
Fig. 2. Bipolar powering for GLM.
LETTERS FROM CROWN MICROPHONE USERS
Miking a discussion group
I have to pick up the sound of a roomful of people. They occupy several desks in an 80’foot square
room with two people at each desk. The ceiling is 20' high. Any ideas?
Dan Kahn, Highland Park, IL
Reply:
Try these suggestions, Dan: For maximum clarity, use one PCC-160 per desk into an automatic mic
mixer. Or use one PCC-200 per desk into an ordinary mic mixer. The PCC mics are supercardioid
surface-mounted microphones, and provide extraordinary clarity.
If budget is a problem, use four PZM-6R or PZM-30R microphones on the ceiling as shown in Fig. 3.
This should provide even coverage of the area. The PZMs at a distance will pick up more room
reverberation than the closeup PCCs, but may be quite adequate if the room isn’t too live.
Fig. 3. PZM mics on ceiling.
PZM stage miking
I’m miking a theater stage with three PZMs, but the sound quality and gain are not too good. What do
you recommend?
Luella Latozke, Neche, ND
I am interested in using my Crown PZMs for sound reinforcement of amateur musical theatre in a 600
seat proscenium arch theatre.
My problem always seems to be that the “small” voices on stage get lost in the fly tower while the
orchestra in the pit in front of the proscenium is loud.
Steve Tinkler, Technical Director, Keyano Theatre, Alberta, Canada
Reply:
PZMs pick up in all directions, and that may be your problem. You need to make them pick up only in
front (where the actors are) and reject sound from the rear. This will result in a clearer sound with less
feedback.
One solution is to make a corner boundary assembly, first suggested by PZM pioneer Ken
Wahrenbrock:
1. For each PZM in use, you need three sheets of clear plexiglass or lucite, 1/4" thick and 18 inches
square.
2. Use L-brackets or cyanacrylate adhesive (Super Glue[tm]) to assemble the sheets into a corner
form.
3. Remove the PZM cantilever (mic-capsule holder) from its plate, and mount the front or nose of the
cantilever tightly into the corner. Maintain the small air gap under the mic capsule.
4. Use as few of these assemblies as possible (one to three). Place them across the front of the
stage floor about 1 foot from the edge.
Also, turn up only the microphone nearest the person talking. Every time you double the number of
open mics, you decrease gain-before-feedback by 3 dB. The more mics you have on, the more feedback and the less clarity you’ll have.
The best solution is to replace each PZM with a Crown PCC-160. This is like a directional PZM but
needs no plexiglass panels. It has a special mic capsule that picks up from the front but rejects
sounds from the rear.
###
MIC MEMO
Winter, 1990
Bruce Bartlett, Editor
UP WITH PEOPLE TROUPE RELIES ON CROWN MICS
Up With People is the world-famed ensemble of young international performers who inspire listeners
with hope for humanity. The group performed its 25th anniversary special in the new Denver Convention Center with many dignitaries attending.
Weeks before the performance, Jens Kirkeby, chief sound engineer for Up With People, asked Crown
for recommendations on miking the group. He needed to mike two choirs, lead vocalists, and acoustic
guitars; and to pick up the audience for a television feed.
Crown and Kirkeby worked out these microphone techniques:
To pick up audience reaction, one SASS stereo mic was hung 30 feet over the audience.
Crown CM-200 cardioid condenser mics (Figure 1) were used for handheld vocals. To prevent breath
popping, a foam windscreen was placed on each microphone. Singers held the mics with lips touching the foam windscreen to maximize gain-before-feedback. Kirkeby compressed the lead vocals.
Fig. 1. Crown CM-200
CM-200s were also used for on-air television reports, for audio and video recording and for guest
speakers.
To pick up the front rows of each choir, Kirkeby placed two CM-200s on stands on the floor in front.
He placed two more on the choir risers to pick up the back rows. Each mic pair was about 10 feet
apart (see Figure 2). To compensate for the mic’s bass rolloff caused by this distant miking, Kirkeby
boosted the bass a few dB on his mixer.
Fig. 2. Choir miking for Up With People.
GLM-100s were mounted on acoustic guitars, while an LM-200 covered guest speakers at the lectern.
After trying the Crown mics at the concerts, Jens had this to say:
“The CM-200 was a very natural and good-sounding microphone both for vocals and instruments. It
fit right into our application. The SASS, LM-200 and GLM-100 were great additions to our show and
had a big effect on the end results.”
THE PZM CHALLENGE REVIVED!
We’re bringing back the PZM Challenge, a contest to determine the best recordings made using
PZMs and SASS microphones. If you have any great-sounding, creative recordings made with Crown
microphones, you could be a prize winner. More on the Challenge in the next issue!
SASS DOCUMENTED IN THE AES JOURNAL
If you’d like to better understand the principles behind the SASS stereo microphone — how it works
and how to use it — two papers go into great detail on these subjects. You can find them in the July/
August 1990 issue of the Journal of the Audio Engineering Society.
The titles are “An Improved Stereo Microphone Array Using Boundary Technology: Theoretical Aspects,” and “Practical Field Recording Applications: An Improved Stereo Microphone Array Using
Boundary Technology” by Bruce Bartlett and Michael Billingsley.
Author Billingsley presented another paper on SASS applications at the September 1990 Convention
of the Audio Engineering Society. It was titled “Application of a New Near-Coincident Stereo Microphone Array for Soundtrack, Special Effects and Ambience Recording on Location.”
It can be ordered for a nominal fee from Mike Billingsley, 5 School Avenue, Montpelier, Vermont
05602. Billingsley’s paper offers many practical tips on using the SASS for non-musical applications.
UNIQUE ORCHESTRA MIKING
Ken Kuespert, Director of Field Operations with TPC Production Services, came up with a novel way
to mike an orchestra.
To pick up the sound of an orchestra outdoors, he placed two PCC-160 supercardioid boundary mics
on 2’x3' plexiglass panels on the grass. The mics were 10' back from the ensemble.
Ken reports that the sound quality was surprisingly good.
IMPROVE GAIN-BEFORE-FEEDBACK AT CONFERENCES
Imagine this difficult sound-reinforcement scenario: you want to pick up people speaking at a conference table and amplify their voices through overhead loudspeakers.
The Spring 1990 issue of Syn Aud Con Newsletter showed a novel way of coping with this problem.
As shown in Figure 3, two loudspeakers are mounted in a V-shaped baffle over the table and are
wired in opposite polarity. A PZM is placed on the table exactly between the two speakers.
Fig. 3. Conference microphone/speaker setup.
The opposite-polarity acoustic signals from the loudspeakers cancel at the microphone location, so
the mic picks up very little loudspeaker signal. Yet each person seated at the table can hear the
closest loudspeaker.
Another way to achieve the same effect is to use a single speaker overhead with a bidirectional mic
on the table. The null of the mic’s polar pattern aims at the speaker.
DRUM MIKING WITH PZMs
In the June 1990 issue of Recording Engineer/Producer, writer Mike Joseph recommended these
placements of PZMs for drum miking:
“A pressure-zone-type mic placed slightly in front of the [kick-drum] mouth opening will add a different
quality to the sound... Try taping the edge of two pressure zone mics in a 45-degree V or wedge and
hanging them above and ahead of the drummer’s head. The sound is natural and balanced, although
without a larger boundary plane it is shy below 200 Hz or so.”
PCCs USED IN EMMY-WINNING BROADCAST
The October 1990 issue of Mix describes how several Crown PCC-160 microphones were used to
pick up sound for La Boheme in the Sydney Opera House.
ABC Radio and the Australian Broadcasting Corporation worked closely to produce this broadcast,
which subsequently won an Emmy. Their job was to provide world-class sound, but to conceal all
microphones from view and not interfere with onstage activities.
Five PCC-160 unidirectional boundary microphones were placed near the front edge of the stage to
pick up lead vocals. The signals from these mics were panned to match the stage layout. In addition,
three PZMs provided spot pickup of the woodwinds.
Sound producer Chris Lawrence had this to say about the PCCs:
“The floor-mounted Crown [PCCs] on stage... provided good range, especially in Acts 1 and 4, which
took place in a set with a set upstage. Act 2, with busy crowd scenes alternating with pockets of solo
action, forced us to combine the [PCCs] with shotgun mics attached to the first tier boxes in the auditorium and aimed at crucial positions onstage.”
HOW TO ISOLATE GROUP DISCUSSIONS
Don Peterson, a technical service advisor on Crown microphones, reported that a customer had an
unusal miking problem. In a 30'-square room were four groups of children. Each group was at a table
near each wall. The customer wanted Crown to suggest a microphone technique that would isolate
the sound of each group.
PZMs could not be placed on each table because the children were playing with toys there. When
PZMs were placed on the wall or ceiling near each group, each PZM picked up too much of the other
groups; the isolation was poor.
A solution was to hang a GLM-200 face-down over each table. The microphone’s tight hypercardioid
pattern isolates the sound of each group, and the mic’s small size makes it inconspicuous. Another
useful model for this purpose would be the CM-30 supercardioid mic aiming straight down over each
group.
SASS AND PZMs USED IN “HUNT FOR RED OCTOBER”
In creating the sound track for the submarine movie “Hunt for Red October,” sound-effects wizard
Frank Serafine came up with some novel uses for PZM and SASS mics.
As described in the Sept./Oct. 1990 issue of db magazine, Serafine developed some highly unusual
ways to record underwater sounds:
“I took a film can, filled it with 40-weight oil, put a Crown PZM inside it, and sealed it shut with epoxy
to make it completely waterproof. We threw it in the water and it floated just underneath the surface.
We used it to record all these different kinds of sound effects and movements that we did underwater... Like an underwater sounding board,... it picked up a lot of low-frequency vibrations...”
Another microphone in a film can without oil picked up more of the highs. Serafine recorded in stereo
with two different mics to obtain a variety of sound textures. He also mounted a SASS-P on a boom
over the surface of a swimming pool to record splashing sounds.
The article (which is fascinating reading) reveals many more ingenious methods used by Serafine to
create sound effects.
HOW TO MIKE A CONFERENCE WITH PCCs
This is one of our most frequently asked questions. As shown in Figure 4, use one PCC-160 at arm’s
length between every two people.
The more mics that are on, the poorer the gain-before-feedback. So use either an automatic mic
mixer with PCC-160 mics, or use PCC-200 gated mics with a standard mixer. The gated mics simulate an automatic mixer.
Fig. 4. PCC conference miking.
LETTERS FROM CROWN MICROPHONE USERS
Battery life
What is the battery life of a PZM-180?
Reply: To determine the battery life of any product, you divide the mA/hr rating of the battery by the
current drain of the device in mA.
A Mallory N cell used in the PZM-180 is rated at 580 mA/hours. The PZM-180 has a current drain of
0.5 mA. So the battery life is 580/0.5 or 1200 hours.
###
MIC MEMO
Spring 1991
Bruce Bartlett, Editor
TAKE THE SASS/PZM CHALLENGE!
Have you made a great-sounding, creative recording with PZMs or a SASS microphone? Send it to
Crown, and you may win one of several prizes.
All entries will receive a Challenge T-shirt, while winners will receive their choice of a SASS-P stereo
microphone, two PZM-30 or PZM-6 microphones, or any other two Crown mics (they needn’t be the
same type).
Be sure to tell us when and where you made the recording, and provide sketches of your miking
setup. Indicate whether you’re an amateur or professional recordist.
Acceptable formats are:
*Half-track open-reel without noise reduction or with dbx I or II
*Cassette with Dolby B or C noise reduction
*DAT
*VHS Hi Fi
*Pro Super-VHS Hi Fi.
Please label your tape accordingly. Sorry, entries cannot be returned. This contest closes June 1,
1991.
We’ll judge the recordings separately according to category:
Best PZM recording, amateur
Pop/jazz/folk
Classical
Sound effects
Best PZM recording, professional
Pop/jazz/folk
Classical
Sound effects
Best SASS recording, amateur
Pop/jazz/folk
Classical
Sound effects
Best SASS recording, professional
Pop/jazz/folk
Classical
Sound effects
To improve your chances, make sure your recording is free of noise, distortion, and overall compression. A winning entry should be spectacular. This means a wide dynamic range, beautiful acoustics,
intriguing effects, and so on. You can enhance your rating by using original microphone techniques.
Send your entries to
Bruce Bartlett c/o Mic Memo
Crown International
1718 W. Mishawaka Rd.
Elkhart, IN 46517
Good luck! We hope to share your creative recording ideas with other readers of the Mic Memo.
PCCs SAVE THE DAY
“I can finally hear the actors!” a listener exclaimed as the PCCs were turned up. Central High School
(in Elkhart, Indiana) had just installed PCC-160 directional boundary microphones to reinforce the
actors in a stage production of South Pacific.
Audio/video instructor Nico Valentijn placed three PCC-160s on the stage floor 6 feet from the edge,
and 12 feet apart (Figure 1). A fourth PCC was placed on a small platform off-stage. Nico placed the
mics 6 feet in from the stage edge, rather than near the edge, in order to get the mics farther behind
the house loudspeaker cluster. This reduced the likelihood of feedback.
Fig. 1. Stage miking with PCCs.
Nico set the bass-tilt switch on each PCC to “cut” in order to reduce feedback pickup, and set a
Rauland-Borg notch-filter to remove feedback frequencies.
To further reduce feedback, the sound mixer for the show followed the action with the mixer faders,
turning up only the microphone closest to the person speaking. This also resulted in a clearer, less
hollow sound than would be heard with all the mics on.
Before installing the PCCs, the school tried some conventional microphones, each in a mic mouse
(foam holder). Nico complained that the resulting sound was dull, and the mics picked up too much of
the pit orchestra. But when PCCs were substituted, the sound quality was natural and the orchestra
was inaudible over the sound-reinforcement speakers.
ONE WORLD, ONE SASS
A Crown SASS-P contributed to the magnificent recording and broadcast, One World One Voice.
This production was a collage of performances by musicians around the world, intended to teach
about global issues such as the greenhouse effect, deforestation, pollution and poverty.
According to the Sept. ’90 issue of Recording Engineer/Producer and the Oct. ’90 issue of Mix, producer Rupert Hine and engineer Steve Tayler traveled the world in six weeks, recording artists for the
show as they went.
Tayler’s basic setup was to record with a Crown SASS-P into a DAT. He would group the players
around the SASS to balance them.
“I used a variation of this setup to record the samba group A Vehla Guarda da Portella in Rio de
Janeiro. They played in the street, and everybody was dancing and moving around. Here I used two
DATs and two stereo mics. I placed one stereo mic, the SASS-P, in front of the seated musicians. I
held the other mic and followed the soloists and the singers as they moved about.”
When Tayler recorded the Kodo drummers in a concert hall in Los Angeles, he “felt they were too big
and too spectacular to record with just one stereo mic,” so he “set up three stereo mics and two mono
mics and put them in radically different parts of the hall...It sounded fabulous.”
SASS-P NOMINATED FOR MOST INNOVATIVE MICROPHONE AWARD
At the 1991 Music and Sound Awards (sponsored by The Music & Sound Retailer), the Crown SASSP was nominated as the most innovative microphone of 1991!
TOO MUCH FEEDBACK AND LEAKAGE? TRY A DIFFEROID!
CM-310
Crown makes a microphone that works where no others will: the CM-310 Differoid [Now the CM310A]. It’s a differential cardioid microphone that cancels distant sounds and rejects sounds behind
the microphone. As a result, it provides the most gain-before-feedback, and the most isolation from
leakage, of any mic you can buy.
But don’t take our word for it. Richard Johnson, a sound engineer for HSA/Heather Sound, has this to
say about the Differoid:
“When you get into an environment that’s hideous — loud stage, loud room, bad room — whether it’s
rock and roll or Contemporary Christian, the sweet sound of most microphones tends to be washed
away in the midst of all these problems. That’s where the CM-310 suddenly sounds very, very good.
“It will eliminate a lot of the bleed, and it will be quicker to EQ, both main and monitor. That means
you spend less time EQing the monitors by ringing them out [making them feed back]. You tend to be
able to EQ by sound quality.
“When you get into the stressful, high-power, high-level type of stages with a lot of things going on,
the CM-310 just blows everything else away.
“The closest thing to the 310 in terms of feedback rejection would be the Beyer TGX580 or the Beyer
M88. The two Beyer mics are close in performance to a 310, but they’re not differential, so they still
can’t get as much rejection [as the 310].
“Differential microphones, boy, you can just shove all kinds of stuff at ‘em, and turn ‘em up, and they
don’t care. In those situations, there isn’t anything else that’s gonna do better than that — period!”
Jeremiah Hamilton, Staff Technician with Bernhard-Brown, finds that CM-310s are especially valuable
when the P.A. speakers aim at the microphone:
“In the summer of ’89 we did the Summer Olympic Festival in Norman, Oklahoma, in the major stadium there with about 75,000 people. The problem was proximity feedback because of the volume
level on the field where the announcer was. The speakers were facing right at the announcer, and we
had to have something that would really do the job.
“[Prominent sound engineer] Tom Durell in LA recommended the Crown CM-310; we had a couple
flown in, and it did the job admirably. We’ve used it several times in announcer situations, and we’ve
had no worries at all about speaker proximity.”
UNIQUE ORCHESTRA MIKING
Ken Kuespert, Director of Field Operatons with TPC Production Services, came up with a novel,
good-sounding way to mike an orchestra.
To pick up the sound of an orchestra outdoors, he placed two PCC-160 supercardioid boundary mics
on 2’x3' plexiglass panels on the grass. The mics were 10' back from the ensemble.
LETTERS FROM CROWN MIC USERS
Camcorder Microphone
I’m planning to go into people’s homes with a camcorder in order to videotape parents and children. I
need a microphone to pick up their speech clearly. A PZM-30R was recommended to me. Is this a
good choice?
Frank Palazzo
Temple University
Reply: The PZM-30R will work well and is rugged, but it may be more than you need. The microphone requires a phantom power supply (Crown PH-4B or PH-1A) which is extra hardware to take
with you. Also, the 30R’s output is balanced, low-impedance, while a camcorder requires an unbalanced high-impedance microphone.
Most camcorders have a DC voltage at the external mic jack to power condenser mics. Crown makes
a microphone that can be powered this way: the GLM-100/E. It’s a miniature omni condenser mic
without electronics.
As shown in Figure 2, solder the GLM’s shield and red lead to the ground terminal of a mini phone
plug; solder the white lead to the tip terminal. Connect the mini phone plug to your camcorder, and
you’re in business.
Fig. 2. GLM-100/E miking for camcorder use.
Place the GLM-100/E face-down in a GLM-SM Surface Mount, and tape the mount to a table top near
the people speaking. You have an instant PZM, with no external power supply needed, and it costs
only about $100.
Miking a wandering lecturer
How do you recommend we mike a person speaking at a lectern, where the person often turns to the
right to refer to a projected slide? We don’t want to place a mic stand on the floor to one side because it gets in the way of camera shots. Also, we don’t want to use a lavalier mic because the cable
takes a lot of abuse.
Dale Flora
Bethesda, MD
Reply: For the lectern, we recommend either a PCC-160 or one of the Crown lectern microphones:
LM-200a, LM-190a, or LM-300. The LM-200a has a ball-and-socket swivel mount for silent adjustment and is shock-mounted to reduce lectern thumps. The LM-190a is the same but 3 inches shorter.
If you need an economical microphone, the LM-300 should fit the bill. It’s slim and elegant, and
sounds natural.
You also need a microphone placed off to one side, but with no mic stand. We recommend the Crown
CM-30 miniature supercardioid mic. You can hang it overhead from its 30-foot cable, aiming toward
the lecturer (Figure 3).
Fig. 3. Dual-microphone method for picking up a lecturer.
Normally you’d expect to hear phase cancellations (a filtered tone quality) when two mics are used on
the same sound source. But this shouldn’t be a problem because the talker will be close to one microphone or the other, depending on the direction he or she is facing. Thus the 3-to-1 rule will not be
violated, and phase cancellations should be minor.
More on wandering lecturer
We’re using an LM-200a on our lectern. How far can a person move in front of the microphone and
still get picked up? Our minister likes to wander around the side of the mic, and then we can’t hear
him.
Reply: The LM-200a has a fairly tight polar pattern (supercardioid) to prevent feedback. If the talker is
1 foot from the microphone, he or she can move 1-1/2 feet either side of center and remain at a constant level.
For wandering lecturers, we recommend either a PCC-160 or a lavalier microphone such as the
Crown GLM-100 or GLM-100/E. The GLM-100 ($199 list) comes complete with an electronics interface for phantom power. The GLM-100/E ($99 list) is a mic capsule and cable which you solder to a
miniature connector and use with a wireless transmitter. This is a good solution for the person who
likes to walk while speaking, but doesn’t want to drag a mic cable.
Purr Pickup
As the owner of an extremely affectionate, large male cat, I have tried to convincingly record his
purring. Many microphones out of my collection have been tried, including AKG C12A, Schoeps
M221B, RCA BK-5, and many more.
The most realistic recording was made by
1. Inducing the cat to purr (catnip can help).
2. Laying him on his side.
3. Placing a PZM-6 on his chest. A larger cat provides a larger purr and a larger boundary area for
improved low-end response.
Purr pickup.
Note: A black microphone must be used. The silver-colored microphones attract too much attention
and become toys.
Christopher D. Gately
Chris Gately Audio/Studioteck
Ardmore, PA
Reply: There may be a problem related to the transition in acoustical impedance from the PZM’s
metallic boundary plate to the fur of the cat, resulting in a partial regeneration of sound waves at the
edge of the boundary. I urge you to purrcede with extreme caution [-Editor].
###
MIC MEMO
Summer 1991
Bruce Bartlett, Editor
SUPER SNOOPER MICROPHONE
PZM-11
No, this isn’t an ad for DAK. We’re talking about the PZM-11 security and surveillance microphone.
It can be mounted in the ceiling or wall in a standard electrical outlet box. The PZM-11 is designed to
look like something other than a microphone so as not to draw attention.
Where can you use the PZM-11? Factories, jailhouses, classrooms, subway platforms, military installations. Put it anywhere there’s a need to listen for intruders, listen for people in trouble, monitor
conversations, or monitor machinery noise.
For easy installation, the microphone connector is a row of screw terminals. The output is balanced,
low impedance, which allows long cable runs without hum pickup or high-frequency loss. Powering is
via 12 to 48 volts phantom power.
Low frequencies below the voice range are rolled off to reduce pickup of air conditioning rumble, and
the highs are boosted to aid clarity and articulation.
YOU CAN WIN THE SASS/PZM CHALLENGE!
Entries have started coming in for the SASS/PZM Challenge, a contest for the best-sounding, most
creative recordings made with PZMs or a SASS microphone. We’ve extended the deadline to July
15, so you still have time to send your entry to the Mic Memo.
Details about the contest were given in the previous issue. Several prizes will be awarded according
to category: pop/jazz/folk, classical, and sound effects.
Good luck! We’ll share your creative recording ideas with other readers of the Mic Memo.
CM-230 TRIDUNDANT CONDENSER MICROPHONE
CM-230
[The CM-230 is no longer being manufactured.]
It’s a triple header! The new Crown CM-230 microphone contains three microphone capsules in a
single housing, feeding an interface box with three transformer-isolated outputs. This triple-redundant
system is more reliable than a single microphone feeding a 3-way splitter.
It’s a special-order unit made for broadcast and other applications that require multiple microphones to
feed separate mixers. In the case of broadcast, the user often needs separate isolated feeds for the
audio pool, in-house P.A., and a backup if the other two feeds fail.
To reduce background noise and feedback, each mic capsule has a supercardioid polar pattern.
Frequency response is wide and smooth for natural reproduction of the voice. A built-in windscreen
suppresses breath pops.
You can mount the microphone either on a gooseneck attached to the interface or on a separate mic
stand. Three-foot and 25-foot multiconductor cables are supplied for connecting the mic to the interface.
The unit has three powering options: phantom power, 12-24 VDC external power supply, or internal
9V batteries. Several switches in the interface let you control and route the signals and system
ground.
VROOM!
David Kniper, a sound engineer in Florida, recorded a spot for Mazda at the Daytona raceway. He
picked up the race cars in stereo with a SASS-P and recorded direct to DAT. John Maselli was project
manager.
According to Kniper, the SASS is a “wonderful piece” with “incredible imaging.” He also used a SASS
to record an ensemble of four acoustic guitars and a string quartet. This recording was processed
through the B.A.S.E. system, which, Kniper says, spreads the sound 12 to 14 feet beyond the speakers.
At the Indianapolis 500 raceway, sound engineer Tom Allebrandi used the SASS-P to record the
Dodge Viper pace car for a promotion. Using a portable DAT recorder, he taped exhaust sounds and
zoom-bys with a SASS-P on a stand nearby. He even rode the car around the track while recording
the engine shifting through the gears. The SASS conveyed an amazing sense of power.
PZMs RECORD BILLY COBHAM’S DRUMS
In the April ’91 issue of EQ magazine, Dan Daley described a recording session engineered by Craig
Bishop. Here’s how Bishop miked the drum set of fusion star Billy Cobham:
“For ambient miking of Cobhams’ kit, Bishop chose a seemingly parsimonious pair of PZMs taped to
the floor three feet in front of the kit and six feet to either side of it. This arrangement is plenty, he
says, giving him a combination of low-end resonance and some added brightness as the cymbals
reflect off the floor. The PZMs were recorded to a stereo pair of tracks.”
CLOSE-MIKING AN ORCHESTRA
How do you reinforce a symphony orchestra? David Scheirman, a concert sound consultant in Julian,
California, asked us that question.
Scheirman needed to mike the 85-piece Moscow Symphony which was playing with a loud English
rock band. Leakage from the rock band into the strings’ microphones was a serious problem.
We offered these suggestions to minimize leakage and increase gain-before-feedback:
*Use a GLM-200 mini hypercardiod mic near each f-hole, aiming across the face of the instrument.
*Roll off the excess bass caused by proximity effect.
*Filter out low frequencies below the fundamental frequency of each instrument.
*Try putting every other GLM in opposite polarity to cancel distant sounds.
*Try two GLM-200’s on each instrument, wired in opposite polarity, as close as possible to each other
without cancelling the instrument. This arrangement creates a second-order hypercardioid, an extremely tight pickup pattern.
*Put plexiglass barriers around the rock band.
*Gate the orchestra mics.
SASS WINDSCREEN IMPROVED
We’ve developed a new windscreen for the SASS that dramatically reduces wind noise compared to
the original version. Plus, it’s one piece — no foam semi-spheres are needed. The new windscreen
is a single piece of fabric with imbedded urethane foam.
You can order a SASS windscreen from Crown’s Parts Department, part no. D7302J8.
LETTERS FROM CROWN MIC USERS
Easy interviews in the street
I record interviews of people on the street and play them on my radio talk show. Can you recommend
any ways to provide hands-free pickup? A handheld mic seems to intimidate most people.
Vic Drescher, WKQX-FM
Reply:
Try placing a PZM-6R in the shirt pocket of the interviewer. The mic picks up both the interviewer and
the interviewee.
If the shirt pocket is made of thick fabric, it will filter out the highs, making a dull sound. So try wearing a thin silk shirt because it allows sound to reach the mic unfiltered. Fortunately, the PZM-6R has a
rising high end which counteracts the acoustic rolloff of the cloth.
The body of the interviewer acts as a boundary or surface which makes the PZM directional toward
the person being interviewed.
Your PZM output could feed either a mini cassette recorder or a cellular-telephone transmitter.
How to mike a walrus
I want to reproduce, over loudspeakers, the sound of walruses in a tank at the Cincinnati Zoo. The
tank has a window in it. If I put a PZM on the outside of the window, will it pick up the window vibrations and reproduce the walrus sounds?
Floyd Cosby
Reply:
Probably not — the window glass does not transmit sounds very well, and the PZM is insensitive to
mechanical vibrations. Try this instead: put a PZM in a sandwich bag and seal it tightly. Test the bag
in a bucket of water to make sure it is watertight. Then attach the mic and bag inside the walrus-tank
window. Let us know what they have to say!
CM-30 conference miking
I want to pick up the conversation at a conference table, amplify it, and send it to an adjoining conference room. The client doesn’t want any microphones on the table because they might be intimidating.
How should I mike the conference table?
Norm Schroff, Consolodated Media, Maitland, Florida
Reply:
For the clearest sound, we’d normally recommend a group of PCC-200 gated supercardioid boundary
mics on the table, one microphone for every one or two people. But if table mounting is ruled out, try
hanging a CM-30 supercardioid microphone over the table (Fig. 1). Remove the hanger and aim the
mic straight down about 3 feet over the heads of the people.
Fig. 1. CM-30 hung over a table.
As an alternative, try a PZM-30R taped to the ceiling over the table. Or you can remove the cantilever
from a PZM-6R and mount the nose of the cantilever in an upper corner of the room.
Minister miking
I’m trying to mike a minister for P.A. in an auditorium, but I’m having trouble with feedback. The minister thinks that wireless mics are unreliable and refuses to use one. We tried an omni lavalier but it fed
back.
At the altar table, the minister gestures broadly with his arms so we can’t put a mic any closer than 3
feet away.
The minister is flanked by two other ministers during his sermon, and maybe they could help by holding microphones. Any ideas?
Reply:
You could have a flanking minister hold an LM-300 gooseneck mic near the minister’s mouth. At the
altar table, place a PCC-160 supercardioid boundary mic as close to the minister as possible. If
feedback is still a problem, try a GLM-200 mini mic instead. Have a flanking minister clip the GLM200 to the minister’s robe a few inches under his chin, taking care to aim the front of the mic at his
mouth. The microphone’s hypercardioid pattern should help reduce feedback. Good luck!
###
MIC MEMO
Fall 1991
Bruce Bartlett, Editor
WINNERS OF THE SASS/PZM CHALLENGE
The results are in for the 1991 SASS/PZM Challenge, a contest to determine the best-sounding and
most-creative recordings using Crown SASS microphones and PZMs.
Every single recording was well engineered, with no audible noise, hum, or distortion. Several were
sonic knockouts.
The winners received their choice of a SASS-P stereo microphone, two PZM-30 or PZM-6 microphones, or any other two Crown mics. Here are the details on each winning recording:
Best amateur PZM recording, pop/jazz/folk
Anne and Gary Wakenhut, The Collecting Consort, Lakeview, Michigan. “Friendship, A Gift” and
“Michigan’s Essence.”
These recordings are of the Wakenhuts playing Celtic, ethnic, and American folk music, with sounds
of nature accompanying many of the selections. The high-quality cassette mastering was done by
Solid Sound Studios in Ann Arbor.
The Wakenhuts recorded themselves playing dulcimer and harp in their living room. The harp was
miked with a GLM-100 about 4' above the floor and 3' from the sound board. They put a plexiglass
boundary behind the mic to block sounds from the dulcimer for better separation.
The dulcimer was placed about 6' in front of the harp. To mike it, they attached a Sound Grabber to a
plex boundary about 1-1/2' above the center of the dulcimer (Fig. 1). The dulcimer was panned left
and the harp was panned right.
Fig. 1. Miking a dulcimer with a Sound Grabber on a boundary.
Gary reported, “We mix with a Realistic 3-mic 2-line mixer (yuk! Maybe that qualifies me as a nonprofessional) and record on a borrowed Ampex ATR 700 that is on its last leg in more ways than one.
“The whistle, flute and pan pipe on the “Friendship” tape were recorded in a high-school gym about 6'
from a Sound Grabber on a boundary. A second Sound Grabber was taped to the bleachers about
25' away for a little essence [room ambience]. Then these recordings were mixed with nature sounds,
and were rerecorded later with Anne playing harp under them.”
One flute was recorded with the dulcimer mic tilted up slightly and about 3' from the flute.
The Wakenhut’s swamp was the scene for other recordings. There recorded a whistle and pan flute
along with the frogs. Gary mounted two Sound Grabbers on a V-shaped plex boundary angled about
210 degrees, with the mics ear-spaced. In one instance, the musician stood 20' in front of the mics, in
another, 25' behind the mics. To reduce traffic noise, the Wakenhuts placed the boundaries’ back
toward the noise and cut the low end. The swamp sounds were mixed with a live mic signal, faded
under or brought up as needed.
Another recording took place in a horse-shoe shaped canyon just after a cleansing thunderstorm. The
Wakenhuts placed Sound Grabbers vertically on the rocks about 6" apart and at a slight angle to each
other for separation. Anne was about 30' below and to the right of one of these, and Gary was above
and about 50' to the left. In one part on the tape, Gary played the whistle 200' further around the
inside rim of the canyon so the mics were picking up only indirect sound waves off the canyon’s rim.
The Wakenhuts sell their tapes at a store frequented by Indians. The owner says it is spooky to note
the emotional and physical responses of the Indians as this canyon piece plays in the background of
the store when they are shopping.
In our listening evaluation, we were impressed with the recordings’ lovely, airy effect and clear, warm
sonics. Sounds of nature were tastefully blended in. This is such relaxing, healing music!
Best amateur PZM recording, classical
Les Feia, St. Paul, Minnesota. “Act II from Die Fledermaus’” recorded May 2, 1991 at St. Cloud State
University, St. Cloud, Minnesota.
To record this opera, Feia placed three PZM-30GP’s across the front edge of the stage, 15' to 20'
apart. He also mixed in overall ambience from two PZM-30F microphones on a 90-degree-angled
plexiglass wedge mounted on the balcony railing.
This recording impressed us with its full lows, crisp highs, and spacious stereo. In spite of the ample
hall reverb, the voices were clearly articulated and lifelike.
In this same category, an honorable mention goes to R.K. Keiser for his recording of the Haydn “Concerto In C Major for Cello and Orchestra,” Penn State University Music Building Recital Hall, September, 1985. Keiser placed two PZMs 6' apart on the front of the stage. The PZMs were removed from
their metal boundary plates and were duct-taped to the stage floor. He recorded without EQ into a
cassette deck using Dolby B.
This effort showed that you can get a reasonable recording with no microphones in sight. The balance and clarity were not as good as you would get with raised microphones. But often, recordists
must compromise mic placement to achieve a clean stage appearance. This on-stage placement of
two PZMs resulted in a good, useable recording.
Best professional PZM recording, pop/jazz/folk
Pierre Sprey, Mapleshade Studios, Maryland. “Clifford Jordan Quartet Live at Ethel’s” (compact disc
MHS 12629A).
Sprey employed a PZM wedge for overall pickup of piano, bass and drums. On the solo sax he used
a Sound Grabber taped to the P.A. mic and aimed end-on toward the sax (Fig. 2). Sprey ran the mics
unbalanced (to avoid transformers) through custom mic preamps into a Sony TC-880 analog tape
deck without noise reduction.
Fig. 2. Sprey’s recording method.
We were struck by the incredibly transparent and detailed sax sound. It was as if a veil were ripped
off the speakers. Cymbal sounds were sweet and crisp.
In this same categrory, an honorable mention goes to Stephen Roane (Irvington, New York) for his
recording of the Dick Weller Band, a jazz/pop group, in the 55 Bar in New York City. After being
delayed while driving to the concert, Roane had to set up at the last minute in a standing-room-only
crowd. In just 20 minutes, he duct-taped the PZMs into place, got levels, and got a Bass Ale.
Roane describes his miking techniques:
“I used a pair of Crown PZM-30F’s, one over the band near the saxophone, on the ceiling; the other
on a side inner wall next to the drums. With both mics, Sonex was used to shape the pattern (Fig. 3).
The two mics went into a Sansui MX-12 mixer with no EQ and no outboard effects to a Tascam DA-30
DAT recorder.”
Fig. 3. Roane’s miking technique.
In spite of the simple microphone technique, this recording sounded surpisingly well balanced and
clear.
Another honorable mention is awarded to Dave Sell, Hatchery Studios, Warren, Michigan, for his
recording of Rob Emanuel playing the drums with a sequenced synth track. Emanual is one fantastic
drummer!
This recording was the soundtrack for a video demo. The recording was done direct to DAT during a
video shoot, and the video was edited to the audio soundtrack.
As shown in Fig. 4, Sell used two PZM wedges to form a “W”. A pair of PZMs were mounted in the
corners of the “W.” He placed these microphones about 15' back in his studio to pick up ambient
room sound. Other mics were used close up on the drum set. We thought the drum sound was
excellent — full and crisp — while the distant PZMs added dimension and power due to the room
reverb.
Fig. 4. Sell’s miking method.
Best professional PZM recording, classical
Andrew Lipinski, Tonmeister Recordings, Bethesda, Maryland. Unidentified orchestral recording, and
a solo piano recording, “Haesun Paik” (compact disc Umkapell 89), Gaston Hall, Georgetown University, Washington D.C.
Lipinski has this to say about recording with PZMs:
“I am a professional recording engineer (M.D. Tonmeister Program) and have been using PZM microphones since the early 80’s. Starting every recording session, I check if I can use PZMs and how to
use them.
“My microphone technique depends on the room acoustics, size and type of the orchestra, quality of
the instruments, etc. I don’t use recipes, but I do LISTEN (I was the only professional recording
engineer who got a 100% score at the National Bureau of Standards on CBS’s DAT anti-copy code
test.)
“I do not hesitate to put PZMs on a wooden floor, to hang them on plexiglass panels of different size
and shape and equalize the bottom end if necessary. Sometimes I use the PZMs as a main pickup,
sometimes as spot microphones. In other cases, I mix them as little as 5% with other types of microphones.
“My favorite model is the PZM-31S (I built my own preamp). My plans are to experiment with the
SASS-B and other types of microphones. Thank you for implementing the PZM principle to the real
recording life; it works for me perfectly!”
Lipinski’s method of orchestral recording is shown in Fig. 5. He reports, “The sound of the PZM
wedge or V was mixed in different proportions with different kinds of regular mics. They were XY in
the center, A-B or A-B-C, usually much closer and lower than the PZM V panel, and sometimes with
spot mics added.”
Fig. 5. Lipinski’s recording method.
In our listening evaluation of the orchestra pieces, we were startled by the clear, articulate sound with
lots of beautiful hall acoustics. Imaging was quite sharp, and the triangle was clean and crisp.
“For my piano recording,” said Lipinski, “I placed the PZM V panel above and behind the head of the
pianist. Another pair of mics were spaced omnis far away in the hall for ambience.”
When we auditioned the solo piano recording, we thought it was miked at just the right distance for an
optimum balance between direct sound and hall sound. The piano was clear and natural, enhanced
by the warm ambience of the hall.
Lipinski noted, “As a general rule for PZM V panels, I found that the relation betrween height and
distance from the sound source to the angle between panels to be very important. Also, the placement of PZMs on each panel should be listened to carefully.”
Best professional PZM recording, sound effects
Gary Pillon, General Television Network, Oak Park, Michigan. “Stearman Fly In” and “New Historians”
video documentaries.
To record these soundtracks, Pillon devised a stereo PZM made of two plexiglass pyramids, with
PZM capsules in the apexes of the pyramids and ear-spaced 8" apart (Fig. 6). He often mounted this
assembly to a Steadicam platform.
Fig. 6. Pillon’s stereo PZM.
Both soundtracks won Emmys, and deservedly so. The detail and presence of the sound tracks
made us feel a part of the events. Crossfades were skillfully done, and the stereo added an exciting
element of realism.
Best amateur SASS recording, pop/jazz/folk
Tom Haneman, General Television Network, Oak Park, Michigan. “Folk musicians at a festival.”
Haneman used a SASS-P and a Sony Walkman Pro to record this group in mid Michigan early last
September. The musicians were sitting in a wooded area behind the festival’s main stage. They sat
close together in a circle (Fig.7).
Fig. 7. Haneman’s miking technique.
Haneman stood a few feet outside the circle holding the SASS-P six feet high. After consulting with
Gary Pillon, they recorded the selected cut into GTN’s Lexicon Opus Digital Audio Workstation, equalized to enhance the high end, then recorded to 1/4" tape.
This recording re-created the immediacy of a spontaneous concert in the woods. We could feel the
pure joy this music expresses. I was surprised to hear how gentle the highs were, almost muted.
Stereo imaging was so precise that we could pick out each individual instrument in the stereo spread.
Best professional SASS recording, classical
Gary Pillon, General Television Network, Oak Park, Michigan. “Fort Street Chorale and Orchestra,
Haydn Mass in D, #3.”
Pillon recorded this large ensemble with a SASS-P specially modified for improved frequency response. He recorded direct to DAT through a pair of Boulder mic preamps. Pillon mounted the
SASS-P about 8' back from the conductor and approximately 15' up on a Matthews light stand.
The sound had a marvelously smooth tone quality with an excellent balance between direct and
reflected sound. The balance between choir, orchestra, and soloists was perfect. Stereo imaging
was quite sharp. This recording proved that less is more!
###
MIC MEMO
Winter 1992
Bruce Bartlett, Editor
NEW SLEEK MICROPHONE FOR CONFERENCE TABLES: THE PCC170
The Crown PCC-160 has long been a favorite for stage miking, but its rugged appearance made it
less appealing for conference table use. So we designed the PCC-170, whose trim, elegant style
looks great on any conference table.
PCC-170
This supercardioid, surface-mounted mic provides clean, clear pickup of speech. The mic’s flat frequency response is especially suited for conference use. Two types of connectors are available for
the PCC-170: a rear-exit mini XLR, or a bottom-mounted stereo phone plug that connects into a jack
in the conference table.
PZM PIONEER KEN WAHRENBROCK VISITS CROWN
Ken Wahrenbrock manufactured the first PZM in 1978. While traveling across the U.S. this summer,
he stopped by Crown to see what we’re up to and share some stimulating ideas. Good to see you
again, Ken!
Ken Wahrenbrock
NEW SASS-P MKII SOUNDS WONDERFUL!
Crown engineers recently developed an upgrade for the SASS-P stereo microphone that greatly
improves its tone quality. Several classical-music recording engineers have field-evaluated this
change, and all thought it was a substantial improvement.
The enhanced model — SASS-P Mk II — sounds warmer and smoother, and has more air or openness in the high frequencies. All this with no change in self-noise or sensitivity.
1991 PZM/SASS CHALLENGE UPDATE
As we reported last issue, the winner of the best professional PZM recording of classical music was
Andrzej Lipinski. We neglected to mention that his recording was of a student orchestra at the National Orchestral Institute at Maryland University.
INTRODUCING THE CM-200A HANDHELD MICROPHONE
CM-200a
Crown is proud to introduce a new handheld condenser cardioid mic, the CM-200a. As the successor
to the CM-200, the CM-200a has a warmer, fuller sound.
The CM-200a was used in the Special Olympics at the Closing Ceremonies. Sigmet’s Sam Helms,
audio-equipment specifier for the Special Olympics, commented on the CM-200a:
“This new version performed unbelievably. The mic had presence; it had warmth, great gain, and low
handling noise. The mix engineer could get a high degree of gain-before-feedback and still retain very
good intelligibility.
“The mic is great. My sentiments were shared by the guys at [major touring sound company] Eighth
Day Sound, as well as Kim Denton, our monitor engineer, who does sound for Steve Lawrence and
Eydie Gorme.”
GLM-200/E PART OF SUPERB GUITAR-MIKING SYSTEM
At the Walnut Valley Bluegrass Festival in Winfield, Kansas, this September, listeners were treated to
some of the best acoustic-guitar sounds they ever heard.
The GLM-200/E was part of a new guitar-pickup system developed by Fishman Transducers and
prominent bluegrass guitarist Harvey Reid. A Fishman pickup mounted under the bridge picks up the
lows and provides volume and punch. A Crown GLM-200/E mini hypercardioid mic is mounted just
inside the sound hole facing in. It provides the treble and the clean acoustic string sound.
The pickup and microphone are mixed in a small 2-input mixer provided as part of the system. The
combination of the pickup and microphone provides a loud, punchy, yet natural sound with all the
crispness of a real acoustic guitar.
Many stellar performers in the bluegrass field used the new system at the festival. Harvey Reid, John
McCutcheon and Dan Crary, among others, were miked with the GLM/pickup hybrid.
A spokesperson for Taylor guitars called this system “the state of the art” in guitar miking. Indeed,
several audience members noticed improved guitar sounds over the year before.
Thanks for this information to Doug Krehbiel, White Pigeon, Michigan.
NEW CM-31 CHOIR MICROPHONE HAS IN-LINE POWER MODULE
Newly available is the Crown CM-31, a miniature supercardioid microphone for overhead miking of
choirs and theatre performances.Unlike the CM-30, which has a power module you mount in an electrical box, the CM-31 has a cylindrical in-line power module.
Crown CM-31 choir microphone.
This arrangement allows more flexible placement of the module. You could place it in a hole in the
ceiling, hang it from a mic cable for easy access, or mount it to a beam overhead.
PCC-160 IS THE SOUND DESIGNER’S CHOICE
In the Aug/Sept. 1991 issue of Theatre Crafts, a survey revealed that, “in the area mic category there
was an almost unanimous favorite: the Crown PCC-160. This microphone can be seen along the
front of the stage on almost every show on Broadway ... and was the clear favorite of resident theatre
designers as well.”
GLM-200 USED TO RECORD MOSCOW SYMPHONY
It was a strange but successful combination: the Moscow Symphony and the rock group ELO. They
performed together in a concert at the Wembley Arena in London. In this concert, David Scheirman
(President of Concert Sound Consultants) used Crown GLM-200 mini mics to amplify the french
horns. (Source: Oct. 1991 R/E/P magazine.)
In the same issue, another article described the use of PZMs by Obie O’brien, supervising producer/
engineer on the live recordings of Bon Jovi’s world tour. “I’d tape a PZM to the bottom of [the
drummer’s] riser and we’d get the direct coupling from its resonance — lots of lows and attacks from
kick and snare.”
MIKING A GRAND PIANO
What are some effective ways to mike a grand piano at a distance? We learned some great tips on
piano miking from Pierre Sprey, owner/operator of Mapleshade Studio in Upper Marlboro, Maryland.
If you just put a mic in front of a piano at an arbitrary spot and it sounds bad, don’t blame the microphone. Experiment with placement to get a sound you like.
First, place the mic stand about 3 to 8 feet from the piano. Close placement gives a detailed, percussive sound; distant placement sounds more spacious.
Raise the mic stand high enough so that the microphone is in-line with the raised lid (Fig. 1). This
reduces pickup of lid reflections and floor reflections which can cause phase cancellations.
Fig. 1. Miking in-line with the piano lid.
The sound is bassier toward the tail of the piano where the bass strings are attached. So place the
mic toward the tail for more bass, or toward the keys for more treble (Fig. 2). Another way to do this
is to leave the mic aiming straight ahead, but rotate the piano to change the recorded tonal balance
(Fig 3).
Fig. 2. Mic placement for piano tone control.
Fig. 3. Piano rotation for tone control.
MIKING A SINGING DRUMMER
Pierre Sprey also had suggestions on this difficult miking problem. He devised an ingenious setup
using a PZM on a boundary to pick up a drummer’s voice without picking up the drum set.
First, Sprey mounted two mic stands on either side of the drum set. Between these stands he
mounted a rod or crossbar which was fitted into a boom holder on each mic stand. He bolted a 2-footsquare piece of plexiglass to the crossbar and taped a PZM in the middle of it (Fig. 4). Sprey placed
the PZM about 1 foot from the drummer’s mouth and angled the plex panel to reject the snare drum
and cymbals (Fig. 5).
Fig. 4. Miking a singing drummer with a PZM.
Fig. 5. Miking a singing drummer with a PZM.
With this setup, the drummer could move around with no change in tone quality or level. The vocal
mic picked up almost no leakage from the drums. The drummer loved the sound and enjoyed being
able to see the band through the panel.
To mike the drum set itself, Sprey placed a PZM wedge (a V made of two plex panels) on a stand in
front of the set. This stereo mic array picked up very little of the vocal because the 2-foot plex panel
blocked the vocal sound. Quite an innovative and effective mic technique!
PZMS MAY BE MORE SENSITIVE THAN OUR EARS
High up in a mountain range in Wyoming, three recordists were shocked by what they heard when
recording there with PZMs. “While at the Cirque of the Towers in the Wind River Mountain Range,
Wyoming, we were recording the music from an instrument we had created in the glacial moraine.
We had placed PZMs on the face of a rock.
“All of a sudden we heard voices over our headphones, so we stopped to listen. When we removed
our headphones, we couldn’t hear them any more. But when we put the headphones back on, we
could hear climbers talking to each other, saying ‘On belay,’ ‘climbing,’ ‘off belay.’
“We looked at all the surrounding peaks and finally found the climbers a half mile away and 1000 feet
up Pingora’s face. The only thing that could have picked up these voices were the PZM microphones
we were using to record.”
Thanks for this information from James Anderson of Performance Audio in Salt Lake City, who advised the recordists on the use of PZMs.
###
MIC MEMO
Spring 1992
Bruce Bartlett, Editor
DIFFEROID ENDS FEEDBACK FOR DAN SEALS
CM-310
Prominent folk artist Dan Seals was hassled by feedback from his stage monitor speakers. Both his
guitar and his hat brim reflected sound into his vocal mic, causing feedback.
John Windham of Morningstar Productions tours with Seals. At an October class of Syn Aud Con,
John was asked about Dan’s feedback problem. He said:
“We no longer have the problem. We are now using the Crown CM-310 Differoid [now the CM-310A].
It has completely solved our feedback problem.”
Tim Rathert, sound designer and mixing engineer for Dan Seals, has this to say about the CM-310:
“The 310s are a closer approximation to the tube mics we use in the studio than anything else we’ve
ever used... A critical choosing point was mic performance with an in-the-ear monitoring system.
With the Differoid, the fidelity that Dan heard was incredible.”
CROWN MICS FEATURED AT OPENING CEREMONIES
Crown microphones delivered the audio at a spectacular event. It was the Opening Ceremonies of
the World Gymnastics Championships, held at Market Square Arena in Indianapolis last September.
Stage 2 Productions provided the audio system and engineering, assisted by John Royer, head of
sound for the Indianapolis 500 Speedway. Celebrities at the event included Bart Conner, Nadia
Commaniche, Sandy Patty and Blackstone the Magician.
How were Crown microphones used at the event?
*Vice President Dan Quayle declared the Games open through a CM-230 tridundant microphone.
Each of the two lecterns used a CM-230.
*The children’s choir was miked with three PCC-160s on the floor, 3 feet from the ensemble (Fig. 1).
According to John Royer, the children sounded close-miked, and leakage was no problem.
Fig. 1. Miking a children’s choir with PCC-160s.
*PZMs on 90-degree plexiglass boundaries picked up the tap dancers effectively.
*Each vocalist sang through a CM-200a handheld microphone.
RECORDING STUDIO RELIES ON GLM-100s EXCLUSIVELY
Musician Doug Krehbiel has put together a recording studio using nothing but GLM-100’s for mics.
(GLM-100’s are miniature omni mics). He especially loves how they sound on acoustic guitar and
drums.
Doug built a vocal isolation booth made of two padded screens with a thick blanket roof (Fig. 2).
Inside the booth, he mounted a GLM-100 on a 2' plexiglass panel. Using the double-sided tape supplied with the GLM, Doug taped the mic face down onto the panel. This forms a PZM.
Fig. 2. Vocal isolation booth with GLM-100 on panel.
The plex panel sits on a monitor mount on a mic stand, and rests against the booth walls.
Doug’s recording equipment is in the same room as the musicians. Any noise problems with this
arrangement? Well, when Doug recorded a singer without the plex panel, the GLM picked up a little
“click click” from the rotating tape reels. But the plex panel eliminated that noise. It also rejected
room ambience and gave a tight, intimate sound to the vocals.
HELPING A PROJECTIONIST HEAR
In an IMAX movie theater — the type that uses an enormous screen and 70 mm film — the projectionist works in an isolated booth. Acoustically removed from the theater, the projectionist can’t hear the
sound as the audience hears it.
A solution was devised by Jim Brown, principal consultant for The Audio Systems Group in Chicago.
He suggested mounting two PZM-20RG microphones in the balcony face. These pick up the sound in
the theater and relay it in stereo to the projectionist.
USING GLMs IN THE THEATER
Here’s a man with lots of experience using GLMs in theater applications. He’s James R. Cummings,
owner of Soundstage 1 recording services, and sound designer for several theatrical troupes that tour
nationally (Sweet Charity, Pirates of Penzance, Pajama Game).
By experimenting with GLMs, Cummings has discovered many insights into GLM usage on stage.
We’re happy to share his ideas here.
The main actors and actresses need wireless lavalier mics. For this application, Cummings prefers
the GLM-100 omni lavalier. One reason is that it is tougher than other mics in handling abuse —
tugging, sweat, heat, cold, and hairspray. Plus, he says, the GLM is easier to hide, easier to paint,
and it sounds great.
Speaking of paint, Cummings found that spray shoe dye holds up the best under sweat.
The usual mic placement at pocket height on the chest doesn’t work too well. Most of the time the
mic must be nearer the mouth for a more intimate sound.
Typically, Cummings runs the GLM cable through the actor’s hair, dead center, and aims the mic over
the forehead down toward the mouth (Fig. 3). The mic cable can be run through a wig and out a hole
cut in the widow’s peak. This placement is especially useful if the actor dances.
Fig. 3. Two effective GLM placements on a theatrical performer.
Another good placement is over the ear, sideways to the head, aimed straight down toward the mouth
(Fig. 3), or against the head aimed straight out. Other positions are on an eyeglass frame or a suit
lapel.
Often, sweat gets into the mic capsule and clogs it up. The mic is okay if dried overnight. To protect
against sweat and hairspray, Cummings wraps the GLM tightly in plastic wrap and secures with a
rubber band. There’s no change in the mic’s frequency response.
Cummings feels that GLMs should be used a lot more on Broadway than they are. “All the theaters
know about PCCs, but not GLMs. If they tried them out, they’d be amazed.”
OFF-THE-WALL WAYS TO USE PZMs
These tips are adapted from an article by Bruce Bartlett in the June 1990 issue of EQ magazine.
Anywhere there’s a hard surface, someone will stick a PZM microphone on it and try to record something! Standard PZM techniques have evolved over the years: you can mike a grand piano with two
PZMs taped to the underside of the lid, pick up room ambience with PZMs on the walls, or record
cymbals with two PZMs over a drum set.
But thanks to ingenious experimenters, many bizarre applications have surfaced. Like these...
*On a drummer’s chest. Chris Altizer devised a chest mount to place a PZM on a drummer’s chest
(Fig. 4). The PZM picks up the set as the drummer hears it — all the toms, snare, bass drum, and
cymbals. Altizer says, “In small clubs, or on large outdoor stages, one PZM beats ten regular mics for
convenience any day in my book.”
Fig. 4. Chest mount for a PZM.
*On your head. Binaural recordists such as Frank Zappa have taped a PZM over each ear, then
played back the recording over headphones. The result? An amazingly realistic sense of space, for
less than the cost of a dummy head.
*On a kick drum head. J. Paul Hancock of AUDIO I/O taped a PZM to a Maxi-Pad and attached the
pad to the kick drum beater head. According to Hancock, “this gave a great kick and snare balance
with an open, punchy snare sound.”
*In a garbage can. For a trashy snare sample, nothing beats a PZM in the bottom of a waste container.
*On the floor by a guitar amp. To fatten the sound of an electric guitar in a demo, Vince Motel laid a
PZM on the floor 3 feet from the speaker cabinet. Then he placed a hard panel 6 feet from the cabinet, behind the PZM. Sound reflections from the panel thickened the sound. By changing the distance between speaker, PZM, and panel, Motel got an ambient sound without adding a second room
mic.
*On drum baffles. Mark Wright, who plays in a Top-40 band, used two PZMs inside a large
plexiglass barrier surrounding his drums. He placed the mics low and in the corners. He also used
one conventional cardioid mic centered overhead and one on top of the snare drum. With this setup,
“I got incredible low end from the toms and bass drums, great highs from the cymbals and Rototoms,
and used only four channels on the main board. The barrier also cut down my stage volume.”
Alfred Grunwell of Calf Audio devised a unique method of drum miking. “We have a flying V
plexiglass unit that we use for stereo overheads with PZMs. We usually use a PZM in the kick and on
the high-hat. Our newest breakthrough is to tape the PZMs onto the top of the kick, directly under the
mounted toms. And voila — more great sound, bright but deep, lots of attack and plenty of air.”
*In a plastic dish. Producer Gary Reber recorded Buddy Rich’s drum set overhead with two PZMs,
each mounted inside a plastic dish (actually a dome window from a van). A baffled PZM picked up
the bass drum. PZM pioneer Ken Wahrenbrock invented these boundaries, plus a slew of other
intriguing baffle shapes.
*On a percussionist’s chest. Trying to cover a large array of congas, bells, gongs, and wood
blocks? Strap a PZM to the chest of the percussionist. The PZM follows the musician as he or she
moves from one instrument to another. Since only one mic is used, there is little ambient pickup.
*In a stereo microphone. The Crown SASS-P is a stereo PZM microphone. Engineer/Producer
Tom Edmonds used it to record Zoro, the exciting drummer with the Lenny Kravitz band. Edmonds
placed the mic under the cymbals, between the rack tom and floor tom, aiming at the snare about 3
feet away (Fig. 5). Then he added two more SASS mics back in the room for ambience. Within five
minutes, he came up with a sound that, he said, “would have taken hours in the studio to create.”
Fig. 5. Miking a drum set with a SASS-P.
PZMs are great fun to experiment with because conventional mic techniques go out the window. In
fact, I think I’ll go tape some to my house to sample a thunderclap...
LETTERS FROM CROWN MICROPHONE USERS
On the stage in our audiorium, I have five PCC-160s that I can use on the apron. Due to the unusually large depth of the stage [43 feet] I have difficulty in miking the upstage area. Can you suggest a
solution? Also, I am interested in a good method of miking a 12' grand piano.
Larry Stroud, Technical Director, East Carolina University
Reply: First, Larry, try three PCCs instead of five to reduce the possibility of feedback. To mic the
upstage area, hang one or two CM-30 or CM-31 microphones overhead, about 25 feet from the apron.
If you want to mike the piano for sound reinforcement, or for recording pop music or jazz, try this
method: Tape two PZMs or two GLM-100s to the underside of the raised lid. Mount one over the
treble strings, one over the bass stings, about 8 inches down from the hammers.
If you want to record a classical-music solo, try our stereo microphone: the SASS-P MK II. Place it
about 4 to 8 feet away, in-line with the lid.
###
MIC MEMO
Summer 1992
Bruce Bartlett, Editor
NEW PZMs OFFER SWITCHABLE RESPONSE
PZM-30D
PZM-6D
Crown is happy to introduce the PZM-30D and PZM-6D Pressure Zone Microphones, designed for pro
recording, sound reinforcement and broadcasting.
In either mic, you can switch the frequency response to either rising or flat. The “rising” position adds
brilliance and articulation. The “flat” position gives a smooth, flat response for natural sound (Figure
1). It’s like getting two mics in one!
Fig. 1. PZM-30D response.
Intended for studio use, the 30D is especially reliable because it can be used with a rugged detachable cable. The 6D is smaller, and has a thinner attached cable to make the mic inconspicous. It’s
well suited for use on conference tables or plexiglass panels.
The PZM-30D replaces the models PZM-30R and PZM-30F. The PZM-6D replaces the models PZM6R and PZM-6F.
GLM-100s WORK GREAT FOR HARP, DULCIMER
Want to make some beautiful recordings of harp and dulcimer? Take some advice from Anne & Gary
Wakenhut, winners of the 1991 PZM/SASS Challenge. They sent us some tips on miking these
instruments with GLM-100 mini mics. Please refer to Figure 2.
Fig. 2. Miking harp and dulcimer with GLMs.
*Harp sound reinforcement: “The GLM rides about 1/3 of the way up the harp’s sound board. It is
held with an alligator clip fastened to a long length of 1/8" rigid wire, which is in turn attached to the
pillar and perpendicular to it. This places the mic 1/8" from the sound board. There is no dampening
effect which might result if the mic were attached directly to the sound board.
“When feedback is a problem, we rotate the mic so it is not exactly facing the sound board.
*Dulcimer sound reinforcement: “One GLM is mounted in the center of the top edge, about 1/2"
above it and at right angles to the sound board. The GLM looks across the sound board through the
strings. It gives an amazingly good and well-balanced pickup of the whole instrument.
*Flute, pan flute and whistle sound reinforcement: “We attach GLM-100 to the top of a music
stand with a rigid wire similarto the harp mount. This makes the mic easily accesible without the
clutter of a boom stand.
“We are pleased with the GLM-100s in our sound system, which is almost invisible.
*Harp and dulcimer recording: “The pillar of the harp is placed as close as possible to the left side
of the hammered dulcimer. The two mics are placed on a horizontal boom about 14" apart. Both mics
are 2 feet over the soundboards and look down at the floor.
“We get very good presence on both instruments even though the mics are not facing over the ideal
sound sources. The placement gives us a very nice stereo spread for each instrument, as both mics
hear both instruments but still provide adequate separation.
“The natural sound which we have been able to gain through Crown mics has been a very important
part of our success.”
SASS AND PZMs FEATURED IN VIDEOGRAPHY
The January 1990 issue of Videography had the following article about the Crown SASS and PZMs:
“Field Audio Engineer Gary Pillon, a 21-year veteran of General Television Network (GTN), in Oak
Park, MI, recently won his second national Crown PZM Challenge, which is sponsored by Crown
International Inc. to promote innovative use of the company’s PZM and SASS mics.
“Pillon, who triumphed in two categories, received two GLM-200 mics for his PZM sound-effects work
on such videos as The NewHistorians and Stearman Fly-In . He also won a new SASS-P micfor his
music entry for a documentary entitiled The Fort Street Chorale.
“Pillon received his first Grand Prize in the 1984 Crown PZM Challenge, and used his four-PZM microphone prize to win his first regional Emmy for the PBS syndicated program, Miracle on Fort Street.
Pillon is noted for inventing the PZM stereo shotgun that was used in the production of this year’s
PZM winners, and is featured in Crown’s how-to Boundary Booklet. Pillon’s most recent
innovationuses PZM techniques to create an audio/video simulator for exercise environments.”
NEW BOUNDARY MICS OFFER SWITCHING, GATING
In the last issue of the Mic Memo, we introduced the Crown PCC-170: a surface-mounted mic with a
supercardioid pattern. This handsomely styled unit is appropriate for use on the most elegant boardroom table or lectern. Other uses include churches, courtrooms, and council chambers.
The previous model, the PCC-160, has a heavy steel housing to withstand abuse on theater stages.
In contrast, the PCC-170 is designed for conference tables, where appearance is more important than
ruggedness.
Like the PCC-160, the PCC-170 rejects ambient noise and feedback. It’s free of any sonic coloration
caused by sound reflections off the table. And the mic reproduces the voice with a clean, clear, and
natural sound.
Two new models of the PCC-170 have just been introduced:
PCC-170SW: Used on a conference table, this model has an on/off switch so each person can control
their own microphone. The on/off switch is a silent membrane type. By setting a DIP switch, you can
configure how the on/off switch works: touch on/off, momentary on, or momentary off. An LED lights
when the unit is on.
PCC-170SW
PCC-170GT: [Discontinued.] This has internal gating circuitry. It turns on (gates open) when you
speak into it, and turns off (gates shut) during pauses in speech. In multi-mic installations, only the
microphone(s) in use will be on. This makes the sound clearer and reduces feedback.
The gating action of the PCC-170GT is smooth and click-free. It turns on quickly with no missed
syllables, and gently drops down 12 dB during pauses. When the mic is on, a top-mounted LED
flashes. A trim pot lets you adjust the volume level at which the mic turns on.
USING PZMs FOR DRUM MIKING
Want a great drum sound with little fuss? Try these suggestions. In the July, 1991 issue of Home and
Studio Recording , columnist Paul White wrote about how to mike a drum set on a budget. He recommended a pair of PZMs and a pair of dynamic mics.
First place the PZMs overhead for overall stereo pickup. To do this, tape two PZMs to two mic
booms. Place the PZMs 6 or 7 feet above the floor, and 2 feet to each side of the drummer. Angle
them to look at the two toms.
Although PZMs have the best bass when mounted on a large surface, they can be used as they are.
Their sound will be a little trebley, but when mixed with the other mics, the tonal balance should be
right. “The cymbals will sound very bright and natural,” says White.
Put the bass-drum mic on a boom just inside the front head and dampen the drum with a blanket.
Equalize it about +6 dB at 80 Hz and cut some around 150 Hz to reduce boxiness. Place the snare
mic about 3 inches from the head and 2 inches in from the edge. Aim the mic at the center of the
head.
Finally, pan the PZMs hard left and right, and pan the bass and snare to center. You should have a
pleasant drum sound with only four mics in use.
EXORCISE PIANO PEDAL THUMPS!
It’s hard to meditate to New Age piano music when the sound is marred by pedal thumps. The following story tells how to exorcise the thump demon from pianos.
I was recording a solo piano album for Michele Schricker, a local musician. To pick up her grand
piano, I taped two PZM-30Rs to the underside of the raised lid. The sound was excellent — full,
uncolored, and with clear hammer attack. But every time she worked the sustain pedal, the piano
thumped.
By instinct, I rolled off the low frequencies. It helped, but the thumps were still there, and the piano
sounded thin.
Michele’s husband, George, solved the problem. He wedged some folded paper into the pedal
mechanism to limit its travel. A mechanical solution for a mechanical problem. No more thumps!
I’ve learned more good recording tips from musicians than from recording engineers.
HOW TO TAPE A PZM TO A PIANO LID
Don’t use duct tape! It leaves a gooey mess on the piano lid. Instead, use drafting tape, which drafters use to hold paper to their drawing boards. You can find some in an office-supply store.
When used with GLMs, drafting tape prevents marring on any instrument, such as guitar, bass, or
violin.
Normally you’d use a GLM-SM Surface Mount to permanently attach a GLM to a guitar or piano lid.
But if you don’t need permanent mounting, just use drafting tape instead. Place the mic face-up on
the surface and tape the mic in place (Figure 3). Be careful not to cover up the sound-entry window.
Fig. 3. Miking an acoustic guitar with a GLM-100
GLM MICROPHONE ACCESSORIES
There are a wide variety of accessories for GLM mics. [Some of these have been discontinued].
Here’s what they can do for you:
GLM-UM Universal Mount: Supplied with the mic, the Universal Mount lets you attach a GLM to musical instruments.
GLM-TB Tie Bar: Also supplied with the mic, the GLM-TB is a lavalier-type tie clip.
GLM-TT Tie Tac: This is a tie tac that mounts a GLM on a tie.
GLM-SP Stick Pin: The GLM-SP lets you pin the GLM-100 to clothing or other fabric. Either pin it on
outside clothing, or inside to hide the microphone.
GLM-BC Belt Clip: Supplied with the mic, the Belt Clip acts as a strain relief. If the cable gets tugged
on, the mic stays put.
GLM-OHM: Need an inconpicuous mic stand? The OHM Boom Stand Mount is a slim boom mount
for overhead miking of drum sets or choirs. It adjusts easily and securely positions the mic.
GLM-CM Cymbal Mount: Use the Cymbal Mount on a hi hat to position the GLM over the hi-hat
cymbals. The mount isolates the GLM from stand vibrations.
GLM-WS2 Windscreen: This is an open-cell foam sphere that reduces wind noise and breath popping. The smaller GLM-WS3 windscreen is less conspicous, but picks up about 7 dB more wind noise
than the GLM-WS2.
GLM-CH Choir Hanger: Use this to suspend a GLM over a choir and to aim the mic at the choir.
GLM-DM Drum Mount: This device lets you permanently attach a GLM to a tension rod on a drum.
The mount can be folded flat for easy packing.
GLM-HM Horn Mount: Thanks to its soft-rubber clip, the Horn Mount can be attached to a sax or
trumpet without marring the finish.
GLM-SM Surface Mount: This lets you mount a GLM mic near a surface or boundary, turning the GLM
into a Pressure Zone Microphone. The GLM-SM works with both the GLM-100 omni and the GLM200 hypercardioid mics.
LETTERS FROM CROWN MICROPHONE USERS
Using GLM-100 with mixer and transmitter
I’d like to use a GLM-100 [mini omni mic] with a mixing console and also with a transmitter. How can I
do this?
Reply: You’ll probably need two mics: a GLM-100 and a GLM-100/E. The GLM-100 has a balanced
low-Z output which plugs into a console mic input. The mic gets phantom power from the console.
The GLM-100/E is a mic capsule and cable without electronics. It has an unbalanced, medium-Z
output which connects directly to a transmitter.
As an alternative, you can adapt a GLM-100 for transmitter use. Follow this procedure:
1. Plug the GLM-100 into a Crown PH-1B phantom power supply, which is battery powered.
2. Plug the PH-1B balanced output into an adapter to match your transmitter input.
To make this adapter, solder a female XLR to one end of a 2-conductor shielded mic cable. On the
other end, solder a connector that mates with your transmitter. Wire pin 2 to hot; wire pins 1 and 3 to
ground.
Mic on/off switch
We hung two CM-30 choir mics over our choir. We’d like the organist to turn these mics on and off at
the organ. How can this be done?
Reply: A simple way to turn a mic on and off is to wire a SPST switch between pins 2 and 3 of the
mic-cable connector. When the switch shorts across pins 2 and 3, the mic turns off.
However, you might hear a click or pop over your speakers when you flip the switch. Any imbalance
in the phantom voltage on pins 2 and 3 makes a voltage spike when the switch is flipped.
Here’s a popless solution: Amplify the mic-level signal up to line level, then switch the line-level signal.
A small mixer with phantom power will do this for not much money. Place the mixer near the organist,
and run cables to and from the mixer.
###
MIC MEMO
Fall 1992
Bruce Bartlett, Editor
LATEST CM-310 USERS
The CM-310 Differoid [now the CM-310A] is catching on witha variety of musicians. Here are some of
the more recent users:
*Jazz artist Grover Washington, Jr. — vocalists on European tour
*Country artist Martina McBride — lead vocal
*Country artist Travis Tritt — lead vocal
*Country artist Hank Williams, Jr. — lead vocal
*Country artist Dan Seals — lead vocal
*Country artist Aaron Tippin — lead vocal
*Rap artist Hammer — nine choir members.
An engineer with Travis Tritt said “It’s an excellent microphone — we’re very happy with it.”
Tim Prince of Starstruck Entertainment works with Aaron Tippin. According to Prince, “We couldn’t
find a mic that sounded as good with as little feedback as the CM-310. Its unique design allows you
to get high monitor volume without feedback. I love that mic. It’s a real useful instrument.”
Prince said that Tippin tends to have a harsh singing voice, which is well complemented by the flat,
smooth sound of the Differoid. He also said that he doesn’t have to mute the mic when it’s not in use,
because it picks up so little leakage. “It acts like it’s gated.”
The Differoid can be seen on Country Music Television and the Nashville Network in Tippin’s video,
“There Ain’t Nothing Wrong with the Radio.”
Hammer’s monitor engineer, Harald Danker, said that he needed a mic that rejected noise and feedback. Since 14 mics were open on stage at all times, this was crucial. The mics are used by the
chorus or choir of 14 members (now nine). Harald says that he is delighted with the noise and feedback rejection of the CM-310. He notes that the stage is just too noisy for any other microphones
because the band and monitors are very loud.
Hammer chorus member using a Crown CM-310 Differoid.
TRIDUNDANT MICS USED IN REPUBLICAN CONVENTION
At the National Republican Convention this August, Burns Audio used sixty CM-230 Tridundant microphones [no longer available] to cover the event. Each mic picked up the speeches at each delegate
area.
All the mics were plugged into 20 Crown MPX mixers, which are computer-controlled 6-in, 2-out units.
Each mic fed two mixers for redundancy.
A conventional master mixer was used to mix three elements of the program:
1. The combined output of one group of MPX mixers.
2. The combined output of the redundant group of MPX mixers.
3. The lectern microphone.
The person who ran this mixer had to work only two faders at a time.
Another person operated a computer which ran software customized by Crown. With this software,
the operator could switch instantly to any state, either by mouse or computer keyboard. When the
state was selected, the corresponding mic came on and all other mics were muted. Plus, the name of
the state appeared on-screen. A monitor placed at the main lectern showed the person speaking
there when the state’s mic was on.
According to Burns Audio, the CM-230s sounded great, and the computer-switching made operations
much simpler than in the past.
HOW TO MIKE AN ACCORDION
An accordion player asked us how to mike his accordion for sound reinforcement. He had several
requirements:
1. He wanted to move around while playing — not stay in front of a mic.
2. The mic should not pick up adjacent instruments or monitor speakers.
3. The mic should not pick up key noises.
First we suggested that he use a CM-200a cardioid or a GLM-200 hypercardioid. However, he
couldn’t move around when using a CM-200a. And when he attached the GLM-200 to his instrument,
the mic picked up too much mechanical vibration (key thumps).
One solution: use a GLM-100 omni, which has very little pickup of vibration. To make it reject the
monitors, mount it on a plexiglass panel PZM-style — facing the panel and about .020" from the panel.
Place the GLM-100 in a GLM-SM Surface Mount and attach the mount to the plex panel near the
center.
Form the panel into a bracket attached to the accordion by Velcro [tm] (Fig. 1). To avoid standing
waves, slightly angle the panel relative to the accordion. Filter out frequencies below 200 Hz on your
mixer to reduce thumps and feedback.
Fig. 1. An accordion miking method.
SASS ON CD
A Crown SASS-B provided the main stereo pickup for the CD, “Musik und Lieder im Kirchenjahr.”
This German production (Happy Valley Records 1291) features a brass band and choir.
Along with the SASS, the engineer used a John Hardy M-1 mic preamp into a Tascam DA-30 DAT
recorder.
The Mic Memo editor recorded the Hope College choir with a SASS-P MKII. The mic was placed
about 12 feet from the choir in a reverberant chapel. Although the recording is not out on CD yet, it
was used to make cassettes for the choir members. The choir director loved the sound and plans to
make more recordings, possibly for commercial release.
IMPROVING YOUR IMAGE
When you make a stereo recording, it’s important to listen to the quality of the stereo imaging. Is each
instrument easy to localize? Is the stage width too narrow or too wide? Is there a ping-pong effect,
where most instruments are heard from the left or right speaker?
You can improve the stereo imaging of your recordings by knowing more about stereo mic techniques.
Some work better than others.
An easy way to get sharp, accurate imaging is to use a SASS-P MKII stereo mic. It was designed
specifically to optimize stereo effects.
Suppose you’re using two mics to record in stereo. There are three basic ways to set them up: coincident pair, spaced pair, and near-coincident pair (Fig. 2).
Fig. 2. Three basic stereo-miking methods.
The coincident pair uses two directional mics with their diaphgragms aligned vertically, grilles almost
touching, and angled apart. The spaced pair uses two mics of any pattern spaced a few feet apart
horizontally and aiming straight ahead. The near-coincident pair uses two directional mics angled
apart and spaced a few inches horizontally.
The spaced pair tends to provide diffused, unfocused images for off-center sound sources. Imaging is
sharper with coincident and near-coincident methods.
Here’s an easy way to check the imaging of your chosen stereo miking arrangement. Record yourself
speaking at the left side of the performing ensemble, then move left-center, center, right-center, and
right side while speaking. Play back the recording. The left- and right-side speech should come from
the left or right speaker. The left-center speech should be heard halfway off center, and so on. Each
image should be easy to localize.
If the reproduced ensemble does not extend all the way between your loudspeakers, angle or space
the mics a little farther apart. Do the opposite if you hear exaggerated separation — a ping-pong or
hole-in-the-middle effect.
DON’T TOUCH THAT MICROPHONE!
You’ve set up a lectern microphone. The people using it feel that they must lean down and talk into it,
causing breath pops and proximity effect. Plus, most users grab the mic boom to adjust its position,
causing thumps in the sound system.
To solve these problems, you might want to route this article and Figure 3 to people who use the
lectern frequently. The microphone seldom needs to be adjusted for height, since it will pick up
people from 5 to 7 feet high within its pickup angle. And you don’t need to speak close to the mic — it
will pick you up adequately 1 foot away, nearly always without feedback.
Fig. 3. Suggested lectern mic placement.
Some people put a note on the lectern that reads, “Please don’t touch the mic — talk about 8" away.”
LETTERS FROM CROWN MIC USERS
Super vs. hyper
In the Crown Microphone Application Guide, pages 4 and 5 have tables showing that the
hypercardioid pattern has more feedback rejection and reverb rejection than the supercardioid. Yet, if
you look at the area of rejection of the polars, the super appears to have greater feedback and reverb
rejection than the hyper (see Fig. 4). Which is correct?
Fig. 4. Supercardioid and hypercardioid polar patterns.
Reply: The supercardioid does have more rear rejection than the hypercardioid. So a super would
better reject feedback from a floor monitor, for example.
However, the tables in the application booklet apply to reverberant or diffuse-field sound, which approaches the mic from all directions equally — not just from behind. In this case, the hyper rejects
reverberant sound slightly more than the super.
Sound is reverberant when the sound system is indoors and the house speakers are amplifying the
microphone. The sound from the house speakers would be mostly reverberant sound at the mic. So
the hyper would have a slight advantage indoors in rejecting sound from the house speakers. Also,
the null or dead spot of the hyper is likely to aim at the house speakers.
Here’s how to determine the reverb rejection of a polar pattern: Using the formula for the polar pattern,
you calculate the output of the mic at all angles of incidence and add them up. After doing this, you
find that the omni rejects reverb 0 dB, the super rejects reverb 5.7 dB, and the hyper rejects reverb
6.0 dB.
The hyper rejects sounds from the side better than the super. So if you use side-fill monitors, the
hyper should more effectively reject feedback from them, all else being equal.
Here’s a summary comparing the two patterns:
Best rear rejection: Supercardioid
Best side rejection: Hypercardioid
Best reverberant sound rejection: Hypercardioid
Getting the organ out of the choir
In our church, a pipe organ is directly behind the choir. I want to pick up the choir without picking up
the organ. Any suggestions?
Reply: First, mike the choir as close as possible — about 1-1/2 feet in front of the front row, and about 1-1/
2 feet above the heads of the back row. If that doesn’t help, hang the choir mics overhead and aim them
straight down at the choir. The side rejection of the mic will reject some of the organ. Finally, filter out the
low frequencies below 100 Hz to avoid picking up deep organ notes in the choir mics.
Duct tape vs. gaffer tape
In regard to your comments about not using duct tape on guitars or piano lids, I must agree completely. Duct tape is made to hold permanently and often does not come off cleanly. What should be
used, however, is gaffer tape which looks much like duct tape but is made to hold strongly and temporarily. It is available in theatrical supply shops and pro audio stores, but not in hardware stores which
usually sell only duct tape. I have used a top-grade gaffer tape on all sorts of piano lids and never
had any residue left as long as I pulled it off sharply.
Drafting tape can be used but is not as strong (being made to hold only paper) and the adhesive has a
nasty tendency to turn into unremovable goo if left on for a few days.
Donald Wade, Collegium Sound, Inc., Jackson Heights, NY
PZMs in the ceiling
I’m working on a proposal for a training room, and I plan to specify PZM microphones in the ceiling.
The room is 8-1/2 feet high, 30 feet wide, and 50 feet long. How many PZMs do I need? They should
cover the entire room uniformly.
Reply: It’s best to specify the smallest number of mics that will do the job. The more mics that are on
at any one time, the muddier the sound.
Please see Figure 4. Six mics should work fine. The person nearest to each mic is 5 feet away. The
person farthest from that mic who is using it is about 9 feet away. So their levels should be reasonably close. We recommend running the mics through an automatic gated mixer to turn off mics not in
use.
Fig. 4. Miking with PZMs on the ceiling.
###
MIC MEMO
Winter 1993
Bruce Bartlett, Editor
GARTH BROOKS’ MIC: THE CROWN CM-311 HEADWORN
MICROPHONE
CM-311
This is the microphone that country superstar Garth Brooks raves about. It’s the new CM-311
headworn microphone [now the CM-311A.] Brooks and his sound engineers extensively field-tested
the mic, and have used it on tour. Working closely with Brooks’ engineers, Crown engineers designed
the microphone to meet the real-world demands of touring sound.
The Crown CM-311 is a rugged headworn microphone for musicians or sportscasters. It sounds like
the best handheld microphones — full, clear, and distortion-free, even with the loudest singers.
“We’re knocked out by it,” says Brooks’ house mixer, Dan Heinz. “It’s got great articulation, no distortion, no leakage problems, no feedback problems.”
The CM-311 is the latest version of the patented Differoid [registered trademark] technology. Its
cardioid pickup pattern rejects sounds from the rear, such as floor monitors. And its noise-canceling
design rejects sounds at a distance, such as floor monitors, instruments on stage, and crowd noise.
In fact, the CM-311 has phenomenal gain-before-feedback and isolation.
Lightweight and comfortable, the mic’s headband and mic boom adjust to fit any singer. An included
pop filter greatly reduces breath noise and pops. Because of the boom’s unique behind-the-ear design, it does not cover up the singer’s cheek.
Two models are available: CM-311 and CM-311/E. The CM-311 is a headset and a battery belt pack,
which connects to a mixer or any wireless transmitter. The CM-311/E is the headset alone, ready for
use with a 9-volt wireless belt transmitter.
The CM-311 can be powered in two ways: the belt pack’s 9V battery or phantom power. The CM-311/
E is powered by the 9V battery in the transmitter.
On the belt pack, two output jacks are included: an XLR-type which connects to a mixer, and a 1/8"
phone jack which connects to a transmitter.
In situations where the musician plays and sings at the same time, and doesn’t want to be tied to a
mic stand, the CM-311 fills the bill. Sports announcers wearing the CM-311 can follow the action
without getting off-mic. All this with excellent sound, minimal feedback and leakage, in a comfortable,
attractive design.
NIRVANA CHIEF ENGINEER ENDORSES DIFFEROID
CM-310
Craig Montgomery, chief audio engineer for Nirvana, has endorsed Crown CM-310 [now the CM310A] Differoid microphones, using them for all vocal applications in the red-hot band’s live performance.
Seattle-based Nirvana burst upon the rock/pop scene last year with their trendsetting sound, most
commonly described as “grunge metal.” With raw music that’s heavy on guitar distortion, getting the
right mix presents a true challenge for Montgomery and his crew, a challenge made easier since he
discovered the CM-310.
“Our primary problem was the bleeding of extremely loud guitar amplifier noise into the vocal mix,”
Montgomery explains. “It generally runs from three to six dB hotter than our vocals, giving us a very
bad situation with stage monitors. We simply had too much guitar bleeding through and couldn’t hear
our vocals.”
Enter the CM-310. Offering superb gain-before-feedback, the CM-310 is a differential-type cardioid
microphone that provides unmatched suppression of unwanted background noise and rejection of
other stage noise. After discovering the mic, Montgomery, working with touring company Proshow
USA of Seattle, equipped lead vocalist/guitarist Kurt Cobain, bassist Chris Novoselic and drummer
Dave Grohl with CM-310’s for all vocals.
“We had tried a variety of the ‘typical’ mics available for live performance without a lot of success,” he
says. “But the first time we used the CM-310, the unwanted noise went way down. In fact, it was at
least 20 dB quieter than anything we had previously tried.”
Montgomery adds that he has also found the CM-310 very effective in cutting out cymbal sound leakage into the vocal mix of drummer Grohl. “And although Chris (bassist) doesn’t sing very much, he
likes to have an open mic in front of him for interaction with the audience during a show. With the
CM-310, we’re now able to leave his mic open at all times without worrying about destroying the mix.”
Nirvana joins a growing list of top touring acts to employ the CM-310, including Hammer, Grover
Washington Jr., Travis Tritt, Michael Jackson, Bryan Adams, Dan Seals and many others.
Thanks to Keith Clark for this report.
GLM-200 HARMONICA MOUNT
Here’s a great suggestion is from Bob Devlin of Baltimore, Maryland:
Attention, vocalists who play harmonica. Want to do away with the cumbersome mic stand/mic arrangement? Try making this special shock mount system, which holds a GLM-200 mic in the best
position for vocal/harmonica work. It allows you freedom to move. It’s ideal for musicians who play
non-chromatic harmonica in a rack, Bob Dylan style.
To put this system together, you’ll need these materials:
*One 6" harmonica holder rack, available in most music stores.
*Two 1/4" adjustable metal hose clamps (screw type).
*One heavy-gauge metal coathanger.
*One extra firm square of flexible foam, about 1-1/4" square.
*Two elastic hair ties or heavy-duty rubber bands about 2" long.
Please refer to Figure 1 and follow this procedure:
Fig. 1. GLM harmonica mount
1. Cut the coathanger wire into two 3-1/2" pieces. Bend each piece into an “L” shape. Then attach
each L to the lower part of the harmonica frame (the part that opens) with the hose clamps.
2. Cut a piece of foam 1-1/4" square. Then with a sharp knife, make a small slit perpendicular to the
rear of the foam. Into this slit, you will insert the GLM-200. You put the slit in the rear of the square to
have as much foam as possible between the mic and your mouth. This reduces mouth noises and
breath pops.
3. Stretch two elastic bands, one top and one bottom, across the two “L” shaped coathanger brackets
you have secured to the frame. Be sure that those bands are loose, just tight enough to hold the
foam square in place so it won’t fall out. (The looser the bands, the better the shock isolation).
4. Place the foam square, with the GLM-200 inside, between the two elastic bands and adjust the
bands.
5. Isolate the mic cable from thumps and taps by carefully taping it to the harmonica rack frame. Run
it back over your shoulder. At the points where you tape the cable, you might want to place a small
piece of foam around the coathanger wire to reduce cable noise.
To adjust the volume balance between voice and harmonica, vary the height of the GLM within the
foam square. Usually the mic is as high as possible since the harmonica is loud.
SOUND GRABBER ON AUDIOPHILE RECORDS
You might not think that the Sound Grabber mic is high enough quality for a recording studio. But
here’s a notable exception.
An audiophile recording engineer, Pierre Sprey, likes to use the Sound Grabber in his jazz recordings
for vocals and sax solos. Sprey, of Mapleshade Studios in Maryland, has been interviewed in Downbeat, EQ, and High Performance Review. In addition, he was featured in the February 1991 PBS
broadcast of the MacNeil Lehrer News Report.
Sprey is a fanatic about sound quality. He takes a purist approach, typically using a single PZM
wedge to pick up an entire jazz ensemble. The Sound Grabber is a spot mic for soloists. You can
hear the Sound Grabber (and the PZM wedge) in these recordings on the Jazz Heritage label:
“Clifford Jordan Quartet Live at Ethell’s” (MHS 512629A) and “Lonely Woman — the Frank
Kimbrough Trio” (MHS 512628H).
MIKING A STRING QUARTET WITH GLMs
The Turtle Island String Quartet, who records for Windham Hill Jazz, uses GLM-100 microphones on
their instruments for sound reinforcement. Their music is a wonderful, yet sometimes disturbing,
combination of classical, jazz, ethnic, and old time. Some of their records include Skylife (WH-0125)
and Spider Dreams (WH-01934, 10141-2).
They shared these GLM miking techniques with us:
Violin: Glue some foam onto the mic capsule strain relief. Insert the mic and the foam through the
hole in the bridge. The GLM will “float” between the strings and the top of the violin.
Viola: Use the supplied GLM-UM Universal Mount. Clamp the GLM onto the tailpiece, and put the
mic near the side of the bridge.
Cello: Glue some Velcro to cable next to the mic capsule. Glue a mating piece of Velco under the
arch of the bridge. Attach the mic there.
Darol Anger, a member of the quartet, likes GLMs because “you get so much detail.” Feedback from
the monitors is not a problem. He uses GLM-100 omnis because they have no up-close bass boost,
as you would get with the GLM-200 hypercardioid. “We like the Crown mics because they’re built
better.”
PCC RECOMMENDATION
In the August 1992 issue of EQ, an article on theatrical sound design had this to say about the PCC160 supercardioid boundary mic:
“For downstage applications, the Crown PCC-160 is the mic of choice. This half-hemispherical PZM,
when arrayed along the lip of the stage, captures the bulk of the dialog with quality sound and low
susceptibility to feedback.”
LETTERS FROM CROWN MIC USERS
Sound Grabber pad
I’m recording loud music with my Sound Grabber. The signal seems to be overloading my cassette
recorder input, because the sound is distorted any any recording level. Can you suggest a pad for
use with the Sound Grabber?
Reply: See Figure 2. This pad reduces the level by 20 dB, and should prevent your cassette recorder
from overloading.
Fig. 2. Sound Grabber pad
Sound Grabber filter
I like to use the Sound Grabber as a free-field mic, away from any boundaries. But then it sounds thin
and harsh because of the small boundary plate. Is there a simple filter circuit which will restore a
natural sound?
Reply: Try the shelf filter shown in Figure 3. It compensates for the low-frequency shelf of the Sound
Grabber’s built-in boundary. Reduce the value of capacitor C to raise the low-frequency knee of the
shelf. Reduce the value of resistor R to increase high-frequency loss.
Fig. 3. Sound Grabber shelf filter.
Mic applications
One customer phoned us asking how to use Crown mics for a wide variety of applications. Here are
our recommendations:
1. Five people are sitting at a long table on stage at a public meeting. They want to use mics close to
their mouths, and they want to turn the mics on and off.
Suggestion: Mount an LM-300 lectern mic near each talker, and mount the mics in 300SM shock
mounts. Put foam windscreens on the mics. Make an on-off switch for each mic as shown in Figure.
The potentiometer balances the phantom voltage on the two legs of the output cable going to XLR
pins 2 and 3. This prevents on/off clicks.
2. At the public meeting, we also want a floor mic.
Suggestion: Use a CM-200a cardioid mic on a mic stand. Add a foam windscreen to prevent breath
pops.
3. The zoning board sits around a 4' x 12' table, and we want to record their meeting.
Suggestion: Place two PZM-6D microphones on the table as shown in Figure 4.
Fig. 4. PZMs on a table.
4. We want to pick up a children’s choir for sound reinforcement. The children talk too softly to be
picked up with PCC-160s.
Suggestion: Try hanging two CM-31 choir mics just over and just in front of the choir. Also try two
CM-200a cardioid mics on floor stands a few feet in front of their mouths.
PZM pad
To pick up a group of people at a meeting, I’m running several PZM-6D boundary mics into a Shure
automatic mixer. The output level of the mics is too high for the mixer when the people at the table
shout, so the sound distorts. Can you suggest a circuit to cut down the level?
Reply: A 20 pad for a PZM-6D is shown in Figure 5. It should prevent overloading the automatic
mixer. For more loss, reduce the 100 ohm resistor. For less loss, increase the 100 ohm resistor or
decrease the 470 ohm resistors.
Fig. 5. 20 dB pad.
PZM overhead miking
I want to pick up a group of people sitting around a small conference table. They don’t want any mics
on the table. The ceiling is 10 feet high, so a PZM on the ceiling might be too far away. Any ideas?
Reply: Try mounting a PZM-6D on a 2-foot square panel of plexiglass. For flattest response, mount
the mic a few inches off-center. Suspend the panel a few feet over the table top. Tilt the panel about
5 to 10 degrees to prevent standing waves between the tabletop and panel.
Hearing the congregation
In our church services, members of the congregation stand up and testify. When we broadcast these
services, we can’t clearly hear the people testifying, even though we hung a PZM wedge over the
congregation. How can we pick up these people without handing a wireless mic to them?
Reply: It sounds like the PZM wedge is too far from the congregation for a clear pickup. Try mounting
PZMs along the walls near the congregation, and run them through an automatic mixer. Then only the
mic closest to the person speaking will come on. The sound should be a lot clearer.
###
MIC MEMO
Spring, 1993
Bruce Bartlett, Editor
RECORD MADE EXCLUSIVELY WITH GLM-100 MICS
The Crown GLM-100 was the only model of microphone used in the recording, The Story Inside, a
cassette album of folk music by George Schricker. The highly reviewed album includes a wide variety
of songs ranging from moving ballads to catchy folk-rock.
All vocals and acoustic instruments were recorded with GLM-100 miniature omni mics, as described
below:
*Vocals: hung from a boom with a foam windscreen taped around the mic, 4 inches from the singer’s
mouth (Fig. 1).
Fig. 1. Miking a lead vocal with a GLM-100.
*Acoustic guitar: taped to the soundboard face up, halfway between the bridge and the sound hole,
near the low E string (Fig. 2).
Fig. 2. Miking an acoustic guitar with a GLM-100.
*Fiddle and mandolin: taped face up near a sound hole.
*Snare drum: cable taped to the drum rim, with the mic peeking over the top head.
*Cymbal: hung from a boom 1 foot over the cymbal edge.
Bass guitar and synth were recorded direct.
The instruments needed little or no EQ. Vocals needed a little bass boost for warmth. Normally you
get warmth by using a cardioid mic, which has proximity effect. Being an omni, the GLM-100 has no
proximity effect, but you can simulate it with EQ. Also, being an omni, the GLM-100 has less coloration and less breath popping than an equivalent cardioid mic.
If you’d like to hear how the GLM-100 sounds on a variety of instruments and vocals, The Story Inside
cassette is available for $12.00 from:
Heart/Mind Productions
11644 S. Maple
Plymouth, IN 46563
BAFFLES IMPROVE PCC REAR REJECTION
If your PCC-160 picks up too much of the pit orchestra, try putting a small cardboard baffle and a
foam pad behind the PCC. Both measures work well to reject sound behind the mic. The baffle absorbs lows; the foam absorbs mids and highs.
Figure 3 shows a baffle made of thin cardboard (a file folder). It measures 12” long by 6” high, and has
a 90-degree corner. We put a PCC-170 just in front of this baffle. (A PCC-160 would give similar
results). We also put a foam pad just behind the baffle. The foam pad was a 2-foot-square piece of
Sonex with 3” wedges.
Fig. 3. Rear baffle for PCC-170.
Figure 4, top, shows the PCC-170 frequency response, front and rear, with no baffle or foam pad.
The rear response curve was taken with the speaker directly behind the microphone, where an orchestra might be.
Figure 4, bottom, is the same with the baffle and foam pad. The response is rougher with slightly less
lows. But there’s much better rear rejection.
Fig. 4. Effect of cardboard baffle and foam pad on PCC-170 response, rear curve taken directly behind the
mic.
Figure 5, top, shows the PCC-170 frequency response, front and rear, with no baffle or foam pad. The
rear curve was taken with the speaker 30 degrees above the surface, where a house P.A. speaker
might be.
Figure 5, bottom, is the same with the baffle and foam pad. Again, the response is rougher with
slightly less lows, and the rear rejection is much better.
Fig. 5. Effect of cardboard baffle and foam pad on PCC-170 response, rear curve taken with the speaker 30
degrees above the surface.
Not shown are the effects of a 12” x 8” plexiglass baffle with a 70-degree angle. It performed worse
than the 12” x 6” cardboard baffle. A 3/4”-thick vertical foam baffle also worked poorly.
The cardboard baffle alone roughens the front frequency response, but it improves rear rejection of
the pit orchestra. However, it slightly degrades rejection of the house P.A. speakers.
The foam pad alone does not degrade the frequency response. It improves rear rejection of the pit
orchestra.
LETTERS FROM CROWN MIC USERS
Mike or Mic?
[In the Mic Memo], the word mic [is] misspelled numerous times while in other areas spelled correctly.
The correct abbreviation by all respected authorities of the word microphone is not mike (a person’s
name) but mic, the microphone (object).
Garry Matthews, Acoustek Production Services, Vandalia, Ohio
Reply: Thanks for your concern, Garry. I use “mic” for the noun form and “mike” for the past-tense
verb and gerund forms. Here’s why: when the letter “c” is followed by a vowel, the c is pronounced
soft (like s), rather than hard (like k). According to this rule, the word “micing” rhymes with “slicing.”
The word “mic’ing” is correct but clumsy — you stumble over it. I use “miking” and “miked” so that the
words are pronounced as intended. Any more reader comments on this?
Miking a guitar for P.A. with a GLM-100
When I mount a GLM-100 [mini omni mic] on my acoustic guitar, on the sound board, it sounds great
for recording. But it feeds back easily when I use it as a P.A. mic. Are there any guitar-miking positions that sound good and also work well for P.A.?
Brett Keiling, Mishawaka, IN
Reply:
We tried miking a Martin acoustic guitar with a GLM-100 in various spots. Here are the results:
*On the sound board, halfway between the sound hole and the bridge, near the low E string: Most
natural sound but feeds back easily if you face the loudspeaker while playing. However, if the loudspeaker is behind your back, you should get a natural sound and very good gain-before-feedback.
*On the sound board, just outside the sound hole: Weak highs, boomy. Needs -6 dB @ 100 Hz to
sound natural. Feeds back easily.
*Flush with the sound hole, just inside the sound hole: Fairly weak highs, boomy. Needs -7.5 dB @
100 Hz to sound natural. Feeds back easily.
*Flush with the sound hole, centered under the strings: Good highs but boomy. Needs -7 dB @ 100
Hz, -2 dB @ 1kHz to sound natural. Slightly better gain-before-feedback.
*Inside the guitar, on the surface nearest the performer, centered under the sound hole: Good highs
but boomy. Needs -12 dB @ 100 Hz, -2.5 dB @ 1kHz to sound natural. There’s about 5 dB more
gain-before-feedback here than on the sound board.
*Inside the guitar, suspended 2" under the bridge: Dull, bassy. Needs -12 dB @ 60 Hz, +3 dB @ 10
kHz to sound natural. There’s about 7 dB more gain-before-feedback here than on the sound board.
What is the best compromise between natural sound and gain-before-feedback? It seems to be with
the mic inside the guitar, on the surface nearest the performer, centered under the sound hole. If you
can play with the PA speakers behind you (no monitor speakers), then a great-sounding spot is on the
soundboard, halfway between the soundhole and the bridge.
If you wish, you can mount a GLM in that spot permanently and wire it to an endpin jack mounted in
your guitar. Then you can simply unplug your guitar when you’re not playing.
To install the GLM, you’ll need a stereo endpin jack, stereo phone plug, pliers, wire strippers, tape,
soldering iron and solder. Please refer to Fig. 6 and follow these steps:
Fig. 6. Installing a GLM-100 in a guitar.
1. Remove the guitar strings and the endpin (if any).
2. If necessary, drill a hole in the tail of the guitar body to fit a stereo endpin jack.
3. Cut the GLM cable about one foot long so it will reach from the sound hole to the endpin jack.
4. Slip one jack nut over the GLM cable. Tie a loose knot in the GLM cable between the mic and the
nut so the nut doesn’t fall off the cable. Leave one nut and a washer threaded on the endpin jack.
5. Insert a guitar string through the jack hole and out the sound hole.
6. Tape the end of the GLM cable to the guitar string.
7. Pull the GLM cable through the jack hole.
8. Solder the GLM cable to the stereo endpin jack. Short lug - white, midlength lug - red, long lug shield.
9. Insert the endpin jack into the hole you drilled for it. Hold the guitar neck up so the nut falls down
the GLM cable onto the jack threads.
10. Reach inside the sound hole, and tighten the nut onto the endpin jack.
11. Tighten the nut outside the endpin jack.
12. Undo the knot in the GLM cable. Using rubber cement, glue the GLM mic to the inside of the
guitar, on the surface nearest the performer, centered under the sound hole. The FRONT of the mic
should aim at the strings.
13. Solder a stereo phone plug to the cable that goes to the GLM power module. Short lug - white,
midlength lug - red, long lug - shield.
14. At your mixer, set the EQ to -12 dB @ 100 Hz and -2.5 dB @ 1 kHz. These settings are just to
get the sound in the ballpark — adjust the EQ to your taste.
If you’re handy with electronics, you can EQ the mic permanently by changing a component inside the
power module. In the module, take out the screw that holds the XLR connector. Loosen the strainrelief nuts. Pull out the PC board. On the PC board, locate the chip capacitor that is in-line with the
green transformer lead. Unsolder it, and replace it with a 0.047 microfarad chip capacitor. This will
roll off the bass.
GLM-200 makes a great lectern mic
We do a lot of church work. In every installation we do, we put in GLM-200s at the pulpit and lectern
(Fig. 7). Here’s how:
Fig. 7. GLM-200 installation in lectern.
1. Unsolder the plug from the mic.
2. Drill a hole just big enough to accept the flex relief of the mic.
3. Thread the cable through the drilled hole. Make it come out at the bottom of the pulpit/lectern.
4. Re-solder the plug.
Functionally, it’s great. Aesthetically, it can’t be beat. The only thing that is visible is the 1" foam ball.
Gain-before-feedback is never a problem and the lay reader never has to worry, “Am I too close or too
far away?” Never again does the reader have this big gooseneck mass separating them from the
congregation.
Joe Chilcote, Chilcote Audio, Stony Run, PA
Reply: Thanks for the idea, Joe! What Joe has done is to create a hypercardioid boundary mic,
something like the PCC-160.
###
MIC MEMO
Summer 1993
Bruce Bartlett, Editor
IF IT’S TUESDAY, THIS MUST BE BUDAPEST
by Bruce Bartlett
Your mission: Record a 60-voice choir performing in seven cities in Hungary, Slovakia, and the Czech
Republic. Capture these one-time concerts for future release on CD. Your equipment must fit in one
carry-on bag.
This was my assignment as I accompanied the Hope College Chapel Choir on their two-week tour of
Central Europe. Along the way I gathered a lot of tips for on-location recordists and broadcasters.
Equipment
The first step was selecting an easy-to-use stereo mic with sharp and spacious imaging. The Crown
SASS-P MK II worked well. To get the cleanest possible sound, I had a custom mic preamp installed
inside the SASS to give it a line-level output. This way, I could bypass the minimal mic preamp in the
DAT recorder.
On the SASS I mounted a redundant pair of mics: two Crown GLM-100/E mini mics taped to the
SASS housing. The two pairs of mics were wired to a single multi-conductor cable, which wrapped
around the SASS for easy storage.
My portable DAT recorders were redundant, too: a Sony TCD-D10 and a Denon DTC-80P. The SASS
fed the Sony and the GLM’s fed the Denon. If a mic or a DAT failed, there was a backup to cover it.
Good thing, too, since a DAT battery failed part way into the first concert, and a DAT tape locked up in
the second concert. Having a backup gave me great peace of mind!
Powering the equipment was a challenge. European AC power is 220V, 50 Hz, with 2-pin outlets. To
avoid using extension cords, I ran everything off batteries. The DAT batteries were recharged each
night by a charger plugged into a Radio Shack 240V/120V converter. The mics used 9V batteries.
All this equipment, plus DAT tapes, earphones and cables, fit into the SASS carrying case. I cut extra
holes in the case’s foam liner to hold everything. Other equipment included a voltmeter, tool kit, and
folding mic stand.
Recording technique
I was fortunate to record in some excellent acoustic spaces. In one glorious marble cathedral, the
reverb time must have been seven seconds. The choir loved it!
At each venue, I worked out the mic placement during rehearsal. I screwed an extension pipe onto
the mic stand to raise the mic 12 feet. With this high placement, the mic picked up less audience
noise and less sound reflections from the floor.
Fig. 1. Choir miking with SASS-P MKII.
I listened to the choir live and tried to find the spot where the sound was best. The goal was a good
balance between direct and reflected sound. The conductor wanted a distant, blended sound with lots
of reverb, rather than a detailed sound where you can pick out individual voices.
Once I found a good listening distance, I put the mic a little less than half this distance to the choir.
For example, if the choir sounded best from 40 to 45 feet away, I put the mic 15 to 20 feet away. That
way, the monitored mic signal sounded like the live sound.
A mic must be placed closer to a musical ensemble than the best live listening spot. If you place a
mic in the audience area where the sound is good, the recording will sound too reverberant (muddy)
when played back over speakers. That’s because all the recorded reverb is concentrated into a line
between the speaker pair, rather than spread around the listener.
I set up the mic stand, mic and recorders in ten minutes. Then I sat with my DAT machines in the pew
next to the mic stand. To keep people from tripping on the mic cable, I taped it down. During rehearsal, I set the record level to -3 dB during the loudest part of the performance. That allowed 3 dB
of headroom in case the concert was louder than the rehearsal. I left the level alone, and ran the DAT
tape continuously.
Editing
Time to edit the DATs back in the studio. I used a Turtle Beach 56K 2-track digital workstation. Its
digital EQ helped to filter out rumble below 80 Hz, and to boost the bass voices in recordings where
they were weak. I wanted the basses to be full but not boomy; the sopranos clear but not over-sibilant. I edited out audience noises where I could, faded applause, and “leadered” each song for precise starts and stops.
Some recordings lacked a sense of space because they were made in a “dead” room. To fix this I
added artifical reverb to the DAT’s analog audio output signal.
Finally, the choral director chose the best performances from all the concerts, and I compiled them
into the master DAT tape for release on compact disc. The director and the choir were delighted with
the sound. I found the recording system easy to carry, quick to set up, and reliable.
NIRVANA TOURS WITH THE DIFFEROID
In the January 1993 issue of Mix, Nirvana’s system engineer, Dave Stevens, described how the major
rock group started using Crown Differoid microphones:
“Prior to enlisting these new mics for the Nirvana shows, sometimes the guitar tones were being
hollowed out by a lot of SPL coming offstage. There was an inordinate amount of leakage on the front
line, in large part because everyone has a vocal mic.
“In trying to solve the problem, [house mixer] Craig Montgomery had read an article touting the virtues
of Differoid mics. He asked for some, and we obliged. The first time they were used was at the MTV
Music Awards, and they performed admirably.
“During the dates in September, we found that you could trim the microphones at a level that wouldn’t
pick up noise from the stage even when you backed away from them. A lot of phase canceling occurs
except [for sound directly on axis]. As a result, that ‘whoosh-whoosh’ you typically get with a dynamic
cardioid microphone when the vocalist steps away was gone.”
Restless Heart also used Differoids when they performed on the Jay Leno show.
PHANTOM POWER HARMLESS TO DYNAMIC MICS
You can plug a dynamic mic into a phantom power supply without damage and without clicks. Figure
2 shows why.
Fig. 2. Circuit of a dynamic mic plugged into phantom power.
Phantom power is a positive voltage applied equally to XLR pins 2 and 3. The negative of the supply
is applied to pin 1. In a condenser mic, the phantom-supply current passes from pins 2 and 3, through
the mic circuit, and back through pin 1 to the supply negative. But in a dynamic mic, pin 1 is the
housing ground, and is not connected electrically to the voice coil. So there is not a complete circuit,
and no current can flow through the voice coil.
WHAT’S WRONG WITH THIS PICTURE?
Here’s a little quiz to check your understanding of stereo mic techniques. Figure 3 shows a bird’s-eye
view of several miking methods, all using cardioid mics. Those in the left columns are wrong: they
result in poor stereo imaging or bad balance. Those in the right columns are correct: they tend to give
accurate, sharp imaging.
Fig. 3. Wrong and right stereo miking methods.
You might want to guess what the problems are with each lettered technique. The answers are below.
First a disclaimer. These “rights” and “wrongs” are not absolute. There might be situations where
doing it “wrong” works best, or is your only option due to visual constraints.
A. Technique “A” is a coincident pair of cardioid mics angled 0 to 90 degrees apart. The mics are not
angled apart enough to give a wide stereo spread. You’ll hear a narrow stage width unless the musi-
cal ensemble surrounds the mics in a semi-circle. If you substitute a pair of bidirectional or
hypercardioid mics, however, an angle of 90 degrees can work great.
Sometimes you want a stage width that does not extend from speaker to speaker — say, for a string
quartet or a piano/vocal recital. In this case, 90-degree angled cardioids can work well. But the room
reverb will not sound very spacious.
B. Here, the mics are angled too far apart. You’ll hear a hole in the middle. Plus, instruments in the
center of the ensemble are picked up 90 degrees off axis to each mic, so they will tend to sound dull
or tonally colored.
C. The diaphragms of the mics are not vertically aligned. The slight horizontal spacing between mics
will cause the highs to roll off in mono. That is, there will be phase cancellations at high frequencies
when both channels are combined to mono.
D. In this method, the mics are spaced apart and angled inward. The left-spaced mic is aiming right;
the right-spaced mic is aiming left. This creates conflicting time and amplitude cues. You’ll hear
vague, inaccurate imaging.
E. The spaced mics are so far apart, you’ll hear exaggerated separation. That is, instruments slightly
off-center will be reproduced from the left or right loudspeaker. Adding a third mic in the center tends
to restore accurate imaging.
I hesitate to call the left pair in E “wrong” because it has a lot going for it. For one thing, it’s less
conspicuous. Sometimes this is the most important consideration. Also, the spaced pair can work
well on a wide sound source, such as a pit orchestra for a musical. And since there’s no center mic,
you don’t need a mixer. You can run the two mics directly into your recorder or mic preamps.
F. Here, the mic is much closer to the front-row musicians than to the back-row musicians. So the
front row will sound too loud relative to the back row. The mic is not raised enough to get a good
front-to-back balance of the musical ensemble.
The next time you do a stereo remote, listen to what the mic placement is doing to the stereo imaging
and to the musical balance. Can you localize each instrument clearly? Is the reproduced stage too
wide or too narrow? Does the ensemble have a natural balance? The answers will help you refine
your techniques.
LETTERS FROM CROWN MIC USERS
Sound Grabber helps out at spelling bee
Our school district’s spelling bee organizers wanted an especially clear voice recording so that they
could check back on any disputed spellings. Patching into the house system is difficult, and the levels
vary widely because the kids are different ages and sizes.
I used a Sound Grabber taped onto the mic stand just above the adjusting collar, and fed it to the
VCR on auto-level. It worked great! The judges even used it as a monitor (the VCR has a built-in
CRT and speaker) and could hear much better than they could with the house P.A.
Robert Buchholz, Sunnyside School District, Tucson, AZ
Microphone ground loops
We’re using PZM-6D mics in a courtroom. When we plug the mic’s power module into a floor jack, we
get hum. The jack is tied to grounded conduit.
Kurt Gish, Indianapolis, IN
Reply: It’s likely that a ground loop has been set up between the jack ground and mixer ground. This
causes hum. Here are some waysto get rid of it. Try one or all of these:
1. At the floor jack, disconnect pin 1 from the jack chassis.
2. Between the mic and the floor jack, add a cable with an XLR on each end, with each shell floating
from ground.
3. Ground the mixer to the same point as the conduit ground.
Mounting a PZM in a corner boundary
We are fabricating some acrylic boundaries: the PZM pyramid and PZM-2. What is the recommended
distance of the microphone tip from the apex of the pyramid and the corner of the PZM-2 boundary? I
have your model PZM-30D microphone.
John Deane, The Laser Workshop, Anaheim, CA
Reply: In general, put the tip of the microphone completely into the corner. This prevents phase
cancellations due to delayed sound reflections from the corner. Here’s how to install a PZM in a
corner boundary:
1. Unscrew the mic from the plate (Fig. 4).
2. Mount the mic so that its tip touches the apex of the pyramid, or the corner of the PZM-2 boundary
(Fig. 5).
3. A PZM-6D microphone is preferred for corner mounting over a PZM-30D. The PZM-6D is much
easier to mount.
Fig. 4. Unscrew mic from plate.
Fig. 5. Mount mic tip in apex of pyramid.
###
MIC MEMO
Fall 1993
Bruce Bartlett, Editor
38 SPECIAL LOVES DIFFEROIDS
38 Special
The popular Southern-rock band, 38 Special, is using Crown Differoids (CM-310’s) on all their vocals
and guitar amps. They say that the 310 sounds natural, and has no feedback or ringing problems.
According to group member Rob Wilson, “We enjoyed using the CM 310’s on our triple bill with REO
Speedwagon, Cheap Trick and .38 Special. We had a consistently superior vocal sound for all
shows.”
The Differoid is catching on. In fact, Crown Differoid mics were nominated for EQ and Mix magazines’
1993 Tec Awards. The CM-310 and CM-311 were considered to be “an outstanding technical
achievement in microphone technology.”
WILL A SASS WORK FOR P.A.?
Yes, if you use it outside. That’s the report from Crown’s Dr. Clay Barclay, who found that a SASS
stereo mic worked well outdoors at the Elkhart Jazz Festival. He used the SASS to mic drums overhead, and to pick up a youth band. There’s no feedback, he says, if you’re careful with levels and put
the speakers well forward of the mics.
HOW TO REDUCE RFI WHEN HANGING CM-31’s
The Crown CM-31 choir microphone has a lot of protection against RFI (radio frequency interference).
To shunt RF to ground, there are capacitors at the mic capsule, as well as at the input and output of
the power module. Ferrite beads at the module input add more protection.
Still, in some areas close to radio stations, the mic might pick up some inteference — especially if the
mic is hung with a long cable. The reason is that the cable attached to the mic is unbalanced, medium impedance. However, the output of the power module is balanced, low-impedance, and is not
susceptible to RF pickup.
In extreme cases, you may want to use a very short cable between the mic and its power module — 8
feet or less. Then run a regular mic cable from the power module to the ceiling. This should eliminate
any RF problem.
THE NEW PZM-11LL LINE-LEVEL MIC
PZM-11LL
For sound contractors who need an inconspicuous mic for security and surveillance, here’s a useful
new mic from Crown. The PZM-11LL is a Pressure Zone Microphone. It’s intended for security and
surveillance uses where 24V AC or DC is available. The PZM-11LL is designed to look like a device,
not a microphone, so as not to draw attention.
The PZM-11LL looks and sounds like the PZM-11, but has a line-level output and is powered by 24V
AC or DC. It can be easily field-converted to phantom. Since the PZM-11LL has a high output, it can
be plugged directly into a VCR line input — no costly mic preamp is needed.
The mic can be mounted in the ceiling or wall in a standard electrical outlet box. It also can be installed without a box because its electronics are shielded inside a removable metal housing.
In the PZM-11LL, low frequencies below the voice range are rolled off to reduce rumble from trucks,
machinery, and air conditioning. High frequencies are boosted to help articulation. Because of its
tailored response and PZM construction, the PZM-11LL picks up sounds with extra clarity.
The microphone connector is a row of screw terminals for easy installation. The output is balanced,
low impedance, which allows long cable runs without hum pickup or high-frequency loss. The mic can
also be wired unbalanced. Powering is by 24V AC, 12-24V DC, or 12-48V phantom.
EQ IMPROVES STAGE-VOCAL SOUND
Suppose you’re miking a vocalist with a CM-200A on a stage for recording or P.A. The sound will be
bassy due to the mic’s proximity effect. If you try to get rid of this by rolling off the lows at 60 Hz, the 500
Hz area will still be emphasized by proximity effect. This gives a “puffy” sound. You might prefer to rolloff
at 150 Hz instead, because this EQ knocks out some of the 500 Hz area. A typical rolloff is -6 to -10 dB.
For P.A., however, you might want to leave the EQ flat, or use only a little rolloff. Most performers
seem to prefer the extra fullness that the bass boost gives their voice when they perform live.
Be sure to put a foam windscreen on the mic. Breath popping is less with lips touching the
windscreen than it is a few inches away.
LATEST SASS USERS
Crown’s stereo mic, the Stereo Ambient Sampling System, is finding wide usage:
*Rupert Hine recorded world music in the field for his album, One World, One Voice.
*The BBC has six SASS-B’s.
*In a National Geographic Explorer video, the SASS is visible on-screen.
*Fox Network soundman Ron Estes uses a SASS, as well as sound designer Frank Serafine.
*The SASS has recorded stereo samples for Akai, Ensoniq, and E-Mu Proteus keyboards.
*Tom McKenny used the SASS to record Paul Winter and the Gyuto Monks at the Cathedral of St.
John the Divine.
*Wylie Statman and John Micelli recorded sound effects with the SASS for the Backdraft attraction at
Universal Studios, Hollywood.
*CBS Sports is picking up golf and other sports with numerous SASS-P’s.
*ESPN uses SASS mics for baseball; ABC uses them for Monday Night Football.
*Turning from the SASS to the GLM-100, the Turtle Island String Quartet (with Windham Hill) used all
GLM-100’s on a recent cassette of their live performances.
GLM-100’s INVISIBLE IN TV CONCERTS
When a concert is televised, a clean stage appearance is important. Video producers appreciate your
finding ways to reduce the clutter on stage.
One way to do this is to put the stage box and snake behind the stage, out of sight. Also, put the floor
monitors in front of the stage below the camera view, or off to the sides of the stage.
Another way to reduce clutter is to get rid of mic stands. In their place, use miniature clip-on mics
such as Crown GLM-100’s. You can clip or tape them to the acoustic guitar, violin, guitar amp, piano
lid, drums, and so on. The stage will look much cleaner.
For example, I recently used GLMs while mixing the sound of a jazz quartet for a TV show. No mics
or mic stands were visible. On the upright piano, I taped a GLM-100 to the middle strut in front of the
sound board. Drums were picked up with a single GLM in the middle of the set, 4" above the snare
and under the cymbals. Another GLM went in the kick, hanging through the vent hole. The sax had a
GLM clipped to its bell, and bass guitar was picked up direct.
Some people who watched the show wondered how the sound could be so close-up and “tight.”
Since they saw no mics, they thought the group was picked up with a stereo mic at a distance!
WHICH IS THE BETTER CHOIR MIC: CROWN PZM OR CM-30?
Many people like to mic a choir with a PZM on a plexiglass boundary. It works well, but the boundary
is difficult to hang and aim. Crown developed the CM-30 choir mic to work as well or better than a
PZM, but without the cumbersome boundary.
How does the CM-30 compare with the PZM? Please refer to the figures.
Figure 1 shows the front and rear frequency response of a PZM-6D on a 2-foot diameter plex boundary. The mic is mounted 4" off-center.
Left: PZM on boundary. Right: CM-30.
Figure 2 shows the same for a CM-30 microphone. The CM-30 has a smoother response. It also
rejects lows and mids better than the PZM. The PZM rejects highs better.
Figure 3 shows the response of the PZM at three different angles: 0 degrees, 45 degrees, and 60
degrees. Because of the PZM’s hemispherical pickup pattern, there is almost no off-axis coloration.
Figure 4 shows the same for a CM-30 microphone. The CM-30 also has almost no off-axis coloration.
In a reverberant room, I talked in front of and behind the PZM. The difference in speech level, front to
back, was 3.5 to 4 dB. I did the same with a CM-30. The difference in speech level, front to back,
was 5 to 8 dB. So the CM-30 has more rear rejection than the PZM in a reverberant room.
I fed the PZM signal through an amplifier and a wide-range speaker, and turned it up just to the point
where it started to feed back or ring. I did the same with the CM-30. The PZM and CM-30 had about
the same gain-before-feedback. The PZM tended to feed back at low frequencies; the CM-30 tended
to feed back at high frequencies. This test might give different results with another sound system or a
different room.
To summarize, here are the advantages of each type of mic:
PZM on a boundary: Rejects highs better, feeds back less at high frequencies.
CM-30: Rejects lows and mids better, feeds back less at low to mid frequencies. Smoother response.
Smaller, lighter, easier to hang and aim.
Both mics have about the same gain-before-feedback, and both have almost no off-axis coloration.
EQ THE SASS TO THE ENVIRONMENT
The Crown SASS-P MKII stereo microphone has a frequency response that is optimized for indoor
use in reverberant concert halls. However, the mic might sound too bright or trebley when used
outdoors, or in a room with weak early reflections.
In the latter case, you might want to equalize the SASS signal to get a more natural sound. A suggested EQ setting is -6 to -10 dB at 10 kHz.
LETTERS FROM CROWN MICROPHONE USERS
Plenty of uses for mics
I use the SASS-P for field audio, interviews, music recording and field gathering of sound effects. It’s
also useful for fill during concert recording, and studio production of multivoiced or chorused talent.
I use the GLM-100 to mic on-camera talent, stage talent at concerts, or public appearance events. I
also record stage talent for archiving. The GLM-100 works for eavesdropping on neighbors for prosecution, and/or civil liability complaints.
David Peter Maus, Maus Productions, Chicago, IL
Phantom problem with dynamics?
The Mic Memo Newsletter is always informative and outstanding and contains a wealth of tips and
information.
You mentioned that phantom power is harmless to dynamic microphones — which is true — but there
can be side effects from leaving the phantom power on. Due to the potential difference between the
coil and the case, noise can be introduced into the mixer mic input. However, this is usually not a
problem except in critical recording situations.
Ken Dickensheets, Dickensheets Design Associates, Austin, TX
Mounting a PZM in a pulpit
Enclosed is a sketch of our church pulpit (Figure 1). The minister does not want any mics visible, so I
suggested a PZM. The pulpit is a rather massive oak structure with a surrounding ledge. How should
I mount the PZM in the pulpit?
Timothy Warner, Consultant, Asheville, North Carolina
Fig. 1. Church pulpit miking with a PZM 6D.
Reply: I suggest a PZM-6D because it is easy to mount. Aim the PZM away from the minister, and
put the nose or tip of the capsule holder tightly into the 90-degree corner of the ledge. This gives two
benefits: 1) It prevents phase cancellations due to delayed reflections off the ledge, and 2) it uses the
ledge to make the PZM directional.
The ledge will boost the midrange, so use your console EQ to cut some midrange for a more natural
sound.
###
MIC MEMO
Winter 1994
Bruce Bartlett, Editor
NEW CM-312 HEADWORN MIC WEIGHS LESS
CM-312
Crown is happy to introduce the CM-312 microphone [now the CM-312A]. It’s a lightweight but rugged
headworn mic for aerobics instructors, musicians, sportscasters, and dance callers.
The CM-312 is like the CM-311 headworn mic except that the microphone is to the side of the mouth
rather than in front. It is designed for applications that require a lighter, less conspicuous mic. It can
be used where gain-before-feedback and leakage are not critical.
The CM-312 sounds like the best handheld microphones — full, clear, and distortion-free, even with
the loudest singers. Its hypercardioid pickup pattern reduces feedback and aids isolation.
Lightweight and comfortable, the mic’s headband and boom adjust to fit any head. An included pop
filter greatly reduces breath noise and pops. Because of the boom’s unique behind-the-ear design, it
does not cover up the user’s face.
Two models are available: CM-312 and CM-312/E. The CM-312 is powered by a 9V battery or phantom power. It has a battery belt pack with a battery on/off switch. The CM-312/E has no connector;
you connect it to a 9V-powered wireless transmitter of your choice.
CM-311 HEADWORN MIC IMPROVED
Crown’s Differoid headworn mic, the CM-311 [now the CM-311A] has been solving feedback problems
for countless performers since its introduction in the winter of 1993. The latest version of the CM-311
is even better. We beefed up the wire frame to stabilize the boom. You’ll appreciate the extra ruggedness and lack of “boom bounce.” The enhanced models went into production by November 15, 1993.
DRUM MIKING TIP
Here’s a unique way to mike a drum set. This technique was suggested by Bob Caracciola, lead
audio technician with the Showboat Casino Hotel in Atlantic City.
To isolate the drums, Bob surrounds the set with plexiglass panels on the sides and front. Then he
mounts two PCC-160 mics on the inside of the front panel about 1-1/2' up from the floor. Those two
mics, he says, are all he needs in most cases to get a great drum sound.
PCCs PICK UP CHILDREN ON TV SHOW
Here’s a tough miking problem: A TV station wanted to produce a show in which about 30 children
answer questions posed by a moderator. The children sit on low steps while the moderator stands. In
the past, the station had used shotgun mics to pick up the kids’ comments. But the mics picked up
too much studio noise and reverberation.
Jeff Mews, senior producer/director at WSJV-TV in Elkhart, asked us for a solution to this problem.
We suggested that he arrange the children into two groups of 15 on either side of the moderator. Mic
them with a PCC-160 supercardioid boundary microphone placed on the floor in front of each group.
Pick up the moderator with a lavalier (Fig. 1). Run all the mics into an automatic mixer. In this way,
only one mic would be on at a time.
Fig. 1. Miking children with a PCC-160.
Jeff did so, and was pleased at the clear, clean sound. We suggest you try this technique in similar
situations.
RESTLESS HEART TOURING WITH CROWN MICS
by Keith Clark
Restless Heart, the popular country-music group recognized for their distinct vocal harmonies, have
recently added several Crown CM-311 headworn microphones for vocal applications.
Restless Heart, recently on a major U.S. tour, evaluated a host of headworn microphones before
choosing the CM-311’s. The mics are used by both of the group’s lead vocalists, John Dittrich and
Paul Gregg.
Monitor engineer David Baker explains that Dittrich, a drummer, wanted more flexibility than that
afforded by stand-mounted mics. In addition, a headworn microphone was also wanted for aesthetic
reasons — stand-mount mics interfere with television and video performances.
Baker adds that Gregg, a bass player, wanted to move more freely about the stage. He is using the
CM-311E, which connects directly to a wireless transmitter that offers even more freedom of movement.
The CM-311 is designed to meet the most demanding “real world” touring sound applications, exhibiting a pickup pattern similar to the patented Crown CM-310 Differoid handheld microphone. It features
superior noise cancelling that provides outstanding gain-before-feedback caused by close proximity of
floor monitors, and also offers superb isolation of high-level stage-instrument sound that can bleed
into the mix.
The mic is lightweight, rugged and comfortable, with the headband and mic boom adjustable to any
vocalist. With its unique behind-the-ear design, the boom does not cover up the face of the vocalist.
“Many of the other headworn mics we tried just weren’t very discriminating. They picked up everything,” Baker explained. “The CM-311 was the only product that provided the consistent rejection of
stage noise without fail.”
CM-310 UPGRADED TO CM-310A
Good news for Differoid lovers: the Crown CM-310 Differoid has been improved. For those who
haven’t heard, the CM-310 is a feedback-killing mic for handheld vocals. The new model, CM-310A,
features these enhancements:
1. The sound is clearer, thanks to a slightly reduced midbass.
2. The mic can handle powerful breath pops without cutting out or blocking.
3. The grille is more streamlined and attractive.
All this comes with no loss in performance. The Differoid still has amazing gain before feedback, and
still prevents bleedthru from distant sounds on stage.
PCC WORKS GREAT FOR PIANO P.A.
Audio consultant Travis Ludwig sent us some great tips on miking a piano for sound reinforcement.
He is the technical director and chief house engineer for “Sunday Nite,” a syndicated live radio show.
The show used many acoustic instruments and floor monitors. As a result, there was a lot of randomincident energy or bleed into every mic on the stage.
The radio engineer and Travis had tried many different mic techniques for the grand piano. They
settled on either a stereo mic or an XY pair of cardioids over the hammers. However, this technique
resulted in enormous amounts of bleed in the piano tracks and limited the gain-before-feedback in the
keyboard monitor mix.
The solution for the radio broadcast was to move the stereo mic under the edge of the piano lid, which
was on the short stick. Although the mic needed to be equalized, there was less stage noise in the
mic.
Travis could not EQ the monitor mixes, and the piano sounded indistinct. So he mounted a PCC-160
on the back side of the piano music stand (Fig. 2). “I located it as far up as visually possible and
aimed it down toward the hammers.”
Fig. 2. Piano miking with a PCC-160.
“I listened to the mains and monitors,” said Travis. “It sounded great!! No midrange buildup. Not only
did it sound terrific, but the rear rejection of the PCC-160 gave us substantially greater gain-beforefeedback in both house and monitors, including the keyboard monitor aimed right at the piano. It even
improved the random noise bleed.”
“I was able to pull the piano out of the mix at will, used NO channel equalization (except a high-pass
filter set at roughly 80 Hz), and the band loved the sound of the piano in the monitors. Radio was
happy with their stereo rig and I thoroughly enjoyed mixing that evening.”
CDs RECORDED WITH GLM-100 MICS
Anne & Gary Wakenhut comprise the group, The Collecting Consort. They make beautiful, peaceful
music on harp, dulcimer, flute, and synth. Recently, the Wakenhuts released two CDs that were
recorded with nothing but GLM-100 mini omni mics.
Gary describes their miking techniques: “The harp and dulcimer were miked with two GLM-100s about
2-1/2 feet apart and about 18" above the instruments. Each mic was rotated away from the opoposite
instrument until we got just the amount of separation we were looking for. I built a platform under the
harp that gave an incredible increase in bass.
“The whistle and flute pickups were done with me standing 8 to 10 feet behind the dulcimer mic. The
pan flute was recorded mostly in a gym, either 75 feet or 6 feet from the mics (Sound Grabbers).
“I ran the synth through two monitor speakers on the floor, aimed up at the mics on each side. Never
thought about placing the mics on the floor — I’ll give that a try next time.”
If you’d like to hear how the GLMs sound on these instruments, you can order the CDs “Spritual
Essence” and “The Earth’s Essence.” They are available from the Wakenhuts at 7363 W. Edgar Rd.,
Lakeview, MI 48850, phone (517) 352-6996.
LETTERS FROM CROWN MICROPHONE USERS
Mic, Mic., or Mike?
You know, the issue of mic vs. mike is one of life’s lesser problems; however, I cannot miss this opportunity to pursue the petty issues.
I have always been a literalist. I believe that life is complicated enough without worrying about strange
rules. If you are using mic as an abbreviation, should it not be followed by a period? Otherwise, it
would be pronounced like stick. We however use the word as a slang for microphone. In that instance, should it not be spelled the most obvious way to sound like you are shortening the word mic-
rophone — mike?
By the way, who remembers the memorization help for the resistor color codes?
Ken Herr, Supervisor, Audiovisual Services, Air Products & Chemicals, Inc.
Reply: Your suggestions make sense, Ken. I’ve also seen mic’ as an abbreviation. And I’ve seen
(yuck) “He mic’ed the piano with a cardioid condenser.”
Literal or not, “mic” is the current usage in most audio trade magazines and on mixer input connectors.
Many audio terms are abbreviations that omit the period: reverb, EQ, aux, atten, auto, synth, preamp,
sync, demag, omni, amp, tech (for technician), mono (for monophonic), stereo (for stereophonic), and
pan pot (for panoramic potentiometer).
The pnemonic phrase for the resistor color code goes something like, “Bad Boys Rob Our Young Girls
But Violet Gives Way.”
Choir miking
I’m miking a choir of 75 people with 3 cardioids. The mics are 2 feet in front of the front-row singers,
and 2 feet above the head height of the back-row singers (Fig. 3). The gain-before-feedback is only
fair, and the mics are picking up too much of the orchestra in front of the choir. Would it help to use
more mics at a closer working distance?
Irving Wood, Northport, NY
Fig. 3. A choir-miking method.
Reply: First, try switching to a supercardioid mic such as the Crown CM-30 or CM-31. A cardioid is 6
dB down at the side; a supercardioid is 8.7 dB down at the side. So if the side of the mic aims at the
orchestra, you’ll gain almost 3 dB of isolation from the orchestra.
Your current working distance is about 6 feet to the center row. If you can decrease this to 4 feet,
you’ll get 3.5 dB more gain before feedback, and 3.5 dB more isolation from the orchestra.
A supercardioid improves gain before feedback by at least 1 dB over a cardioid in a reverberant
sound field. The improvement is better if the sound field is more direct than reverberant, and if you
can aim the null at the loudspeaker.
In general, twice as many mics at half the distance improves gain before feedback by 3 dB.
Compared to 3 mics at 6 feet from the choir (your current setup),
6 mics at 6 feet reduces gain by 3 dB.
6 mics at 4 feet offers no improvement over 3 mics at 6 feet.
38 mics at 1 foot (one mic per two people) increases gain by 4.7 dB but costs 12.7 times as much!
75 mics at 3 inches (one mic per person) increases gain by 13.6 dB but costs 25 times as much.
To cover three people equally, you would need to mic 5 feet away. So there’s no point in trying to
cover groups of three people with 25 mics.
Looks like the best solution is to mic a little closer with three supercardioids or hypercardioids.
###
MIC MEMO
Spring 1994
Bruce Bartlett, Editor
INTRODUCING THE PCC-170’s LITTLE BROTHER: PCC-130
PCC-130
The Crown PCC-130 is a very small, surface-mounted cardioid microphone of professional quality.
This handsomely styled unit can be used on the most elegant boardroom table or lectern. Other
applications include churches, courtrooms, and council chambers.
The PCC-130 sounds like its bigger brother, the PCC-170. But the PCC-130 has been reduced in
size to make it less conspicuous on a conference table. Also, the PCC-130 is cardioid, while the
PCC-170 is supercardioid.
Because of its directional pickup pattern, the PCC-130 rejects background noise and feedback. The
microphone reproduces the voice with a clean, clear, and natural sound.
Inside the PCC-130, a tiny mic capsule is mounted on a boundary or surface. Because of this arrangement, direct and reflected sound waves arrive at the mic in-phase, and add coherently. This
eliminates comb filtering in the audible spectrum and gives a more natural sound. It also enhances
sensitivity, clarity, and reach.
All the electronics are built-in, so you don’t need an in-line preamp box. Powered by 12-48V phantom
power, the PCC-130 has a low-impedance balanced output which permits long cable runs without hum
pickup or high-frequency loss. Although the standard connector option is a Switchcraft TB3M, you
can order the mic with a 1/4" stereo phone plug on the bottom of the base plate as the PCC-130SPP.
Screw holes in the base let you mount the mic permanently.
Capable of handling up to 120 dB SPL without distortion, the PCC-130 will never overload in practical
use. Its electret-condenser capsule provides a wide, smooth frequency response from 50 Hz to 18
kHz. RFI suppression is included. Self-noise is low and sensitivity is very high. A bass-tilt switch lets
you tailor the low-end response for particular applications.
CROWN DEBUTS STRONGER GOOSENECK MICS
Good news for users of Crown lectern mics: we’ve upgraded our line of gooseneck microphones —
the LM-300, LM-300L, and LM-301. The new models have beefier, extra-rugged goosenecks that
continue to stand up under heavy use. Yet the microphones still look slim and elegant. The current
models are the LM-300A, LM-300AL, and LM-301A. All include the new, highly effective WS-9 pop
filter.
Left: LM-300a, Right: LM-301.
NIRVANA AND SOUNDGARDEN RELY ON CROWN DIFFEROIDS
An article in the Jan/Feb ’94 issue of Live Sound described how rock group Nirvana is using Crown
CM-310 Differoid mics on tour.
According to Allan Bagley, Nirvana’s front-of-house sound engineer, the most difficult part of his job is
getting vocal intelligibility and separation in the mix, without mixing [the vocals] at excessive levels.
“Due to the amount of leakage into the downstage vocal mics and drum vocal mic, a different approach had to be used. Conventional dynamic cardioid mics did not have the off-axis rejection that is
required for this show. But the Differoid’s design allows for greater gain before feedback, something
very critical in the show. The CM-310 also has outstanding off-axis rejection, keeping bleed to a
minimum.
“Bagley and [house mixer] Craig Overbay, as well as longtime Nirvana monitor mixer Ian Beveridge,
feel that these [mics] are the key to a good sounding Nirvana show. For over a year, Nirvana has
used the Crown CM-310 for all stage vocal mics, carrying at least six at all times, even for network or
MTV television tapings.”
Soundgarden is another well-known grunge-rock group currently using Differoids on tour.
SURFACE-MOUNTED GLM RESPONSE SHAPING
When you use a GLM-100 mini mic on a surface, such as an acoustic guitar or a piano lid, you can
tailor its frequency response to get a variety of different tone qualities. As Figure 1 shows, there are
several ways to mount the GLM next to a surface, each with its own response.
Fig.1. GLM response shaping
For example, suppose you’re miking an acoustic guitar with a GLM-100 in a surface mount. The
usual placement is near the low E string, halfway between the soundhole and the bridge (Figure 2). If
the sound is too bright, or you hear too much string noise, put the mic in the surface mount face up.
This orientation will roll off the treble, as shown in the bottom-right response graph.
Fig. 2. GLM guitar miking.
HOW TO REDUCE REVERB WITH A PZM WEDGE
A recording engineer phoned Crown to say that he was recording choir and organ in a highly reverberant cathedral with a PZM wedge. A PZM wedge is an assembly of two 2' x 2' pieces of plexiglass.
They are mounted with one edge touching to form a wedge or V. Often the edges are joined with a
piano hinge. The point of the V aims at the sound source (Figure 3-A).
Fig. 3: PZM wedge — angled (top) and folded flat (bottom).
The engineer said that the sound picked up was too live or reverberant. When he moved the mics
closer to the choir (3 feet away), the reverb was under control. Unfortunately, at this distance he
heard individual voices instead of a blend of all the voices.
We recommended that he take the V or wedge, and unfold it flat. Then the two PZMs aim directly at
the choir (Figure 3-B). This way, the mics pick up more of the choir and less of the room acoustics.
That is, they pick up more direct sound and less reflected sound. So the mics can be moved farther
away from the choir to get a better blend.
Also, each PZM was mounted on a 2' x 2' boundary, two of which formed the V. If you flatten out the
V, you get one large boundary measuring 2' x 4'. The boundary seen by each mic is twice as big, so
the boundary rejects lows better.
As a bonus, the stereo array changes from a near-coincident pair to a spaced pair. A near-coincident
pair gives sharp imaging, while a spaced pair gives a more blended effect — which the engineer
wanted.
LETTERS FROM CROWN MICROPHONE USERS
How to mike a hypnotist
CM-312
My client is a therapeutic hypnotist. During sessions, she wants her voice to be recorded, but without
any background noise. Any suggestions?
Mike Peavey, Little Rock, Arkansas
Reply: If the hypnotist doesn’t mind wearing a head-worn microphone, a CM-311 will give the ultimate
isolation from background noise.However, this mic is worn with lips touching the grille. If that’s not
acceptable, the next best choice is the CM-312 [now the CM-312A] headworn mic, whichis off to the
side of the mouth. Your third choice is a GLM-100 lavalier mic.
GLM and SASS enhance voice-overs
I do a lot of voice-over work in an acoustically tight and very dead room. Occasionally, though, I need
a larger, more live and open sound. By positioning my GLM at a boundary, and mixing it in at varying
levels, I can get a unique sound that brings to the voice-over a more natural, less canned quality on
some projects. Equalization and phasing can create some amusing effects. My SASS-P can be used
in the same way to bring depth to stereo projects. The SASS-P is also useful for group voice-overs
without the need for EQ or phasing corrections.
CM-310’s in country station awards show
CM-310
The country music station of the year, WUSN (US-99) Chicago, bought four CM-310’s [now the CM310A] from Graysonics for the event. Broadcasting live from a remote “studio” in Nashville at the
ceremony, chief engineer Bob Larsen was impressed with the quality of the sound of his new mics.
John Grayson, Graysonics, Evanston, IL
No more RFI
An antenna tower within 100 yards of our microphone installation and was causing unwanted radio
interference. After we consulted with Yamaha and Peavey, Crown technicians were the only ones
who were able to completely eliminate the interference. We used ferrite beads and 250 pF capacitors.
Thank you.
Richard Troutman, Troutman Music, St. Joseph, Mo.
Reducing RFI in the Sound Grabber
A number of our court reporters are using Sound Grabber microphones with Marantz tape recorders
as an adjunct to the conventional means of capturing verbal court proceedings via Stenograph machines.
We have found the Sound Grabber to be an excellent microphone. The one problem we have experienced in the tendency of the Sound Grabber to also capture a nearby radio station. Is there a retrofit
that will eliminate such a problem?
Roger P. Clark, Official Court Reporter, Hennepin County District Court, Minneapolis, MN
Reply: Try soldering a ceramic disk capacitor across the mic-capsule terminals. Tack solder — do
not overheat! A good starting value for the capacitor is .0068 microfarad (also called 6.8 nanofarad or
6800 picofarad).
If that doesn’t work, you might try soldering a similar capacitor across the mic-jack terminals in the
recorder.
CM-200A is unique
CM-200A
We install sound systems in churches. The soloists desire a tapered mic, so they can pick it up and
put it back in the stand with one hand. We looked all over for a condenser mic suitable for solo use
that had a tapered body. The only option on the market under $600 that has a cardioid pattern and a
tapered body in the CM-200A. (Many times a hypercardioid is too narrow for ensemble and duet use.)
Douglas Harrell, Audio Specialists, Yakima, WA
SASS in a spookhouse
I provided sound for a couple of spookhouses this Halloween. Among the canned sound effects at
various points in the venues, I dropped in pre-recorded maniacal laughter, narratives, threatening
comments and the like.
To tape them I used a DAT and a Crown SASS-P stereo mic in an absolutely dead room. Working
about three feet from the mic, the stereo image was deep and wide.
When the Klipsch monitors behind the victim released these sounds, after a generous application of
Crown P.A. gain, a delightful wail of terror resulted, and — in at least one case — genuine excremental fright. I’ve already been invited back next year.
David Peter Maus, Maus Productions, Chicago, IL
###
MIC MEMO
Summer 1994
Bruce Bartlett, Editor
MAKING A GREAT MIC SOUND JUST A LITTLE BETTER
by Travis Ludwig
Differential mics have been around for several years. But Crown has managed to refine this application and create an exceptional sounding microphone at the same time. There are, however, a few tips
to consider when using these gems.
CM-310A
The CM-310A does an exceptional job reducing bleed. But there’s a trade-off. If a vocalist attempts
to “work” the microphone, the level drops whenever the vocalist backs away.
By using a standard compressor you can increase the apparent reach or window of the CM-310A.
The compressor must have independent controls for attack, release, threshold, and ratio.
If you set the ratio too high, the threshold too low, or the release time too long, feedback starts to rear
its ugly head. After a little experimentation, something wonderful results. The level doesn’t drop when
the singer backs off the mic. I’ve used this technique for live radio where as many as eight CM-310A’s
are in use simultaneously.
If feedback still seems to be a problem, try putting every other vocal mic out-of-phase with the next.
Make sure to do an A-B comparision before settling on this approach.
One last tip. To improve the performance of the foam pop filter, hold the tip of the filter and gently pull
it away from the ball grille until the bottom edge starts to reveal the grille screen mesh. Now you’ve
created a second air layer between the outer foam and the ball grille. This will greatly increase the
effectiveness against p-pop.
NEW WS-9 POP FILTER STOPS BREATH POPS
WS-9 pop filter
The WS-9 foam pop filter fits on our lectern mic models LM-300a, LM-300aL, and LM-301a. It’s a
major improvement over previous pop filters. Why is it so effective? The WS-9 is a two-stage design.
Mounted in front of the usual foam “sock” is a flat foam disk. It works like the flat pop-filter screens
you see in recording studios. Lecturers will hear noticeably less breath popping when they use the
WS-9.
SASS CONCERT MIKING
In an article in the January, 1994 issue of Electronic Musician, Neal Brighton described how he mics
an orchestra with the Crown SASS-P MKII stereo microphone:
“My favorite concert miking trick is flying the microphones above the audience (Figure 2). At San
Francisco’s Community Music Center, I’ve engineered a number of recordings using a pulley system.
A Crown stereo PZM microphone is hoisted approximately fifteen feet above the audience’s head and
secured with clear fishing line, so that the mic doesn’t twist around in mid-air.
Fig. 2. SASS concert miking.
“Because the Center’s medium-size concert hall accommodates intimate gatherings, this miking
system produces a clear and vibrant stereo recording. Basically, the PZM mic emulates the sound
heard by the audience. I can’t think of a better perspective from which to document a classical concert.”
GLM: A FAVORED MIC FOR STRINGS
In the March 1994 issue of Mix appeared an article titled “The New String Thing.” Author Mark
Fitzgerald covered miking of live string ensembles.
One prominent group of this type is the Turtle Island String Quartet, who improvise in jazz, bluegrass,
and almost any other style. “Their engineer, Brian Walker, works with Turtle Island in the studio and
on the road,” said Fitzgerald. “Walker uses miniature Crown GLM-100s on all of the instruments...”
RECORDING BIRDS WITH A PZM PYRAMID
The venerable PZM pyramid is a highly directional mic system that you can use to record bird calls.
Here’s how:
1. First, make a four-sided pyramid using 3/16" plexiglass as shown in Fig. 3. Seal the edges with
silicone rubber.
2. Insert a GLM-100 microphone inside so it touches the apex of the pyramid, and glue or tape it in
place.
3. Finally, cover the pyramid opening with nylon knit fabric to reduce wind noise.
Fig. 3. PZM pyramid.
Bird calls are not very loud, so you might need a more-sensitive microphone. Try a GLM-100/E and
wire it as shown in Figure 4. The circuit’s output is medium impedance, unbalanced. The sensitivity
will be 11 dB higher with this circuit than with the GLM-100.
Fig. 4. GLM powering circuit.
WARMER, TIGHTER SOUND WITH PCCs
Bob Myers of Sound Comm was using several PCC-160 supercardioid boundary mics to pick up
interviews of the Cleveland Browns at the long conference table. He asked us how to get a warmer,
more intimate sound with this setup.
We offered these suggestions:
1. Use the BOOST position on the bass-tilt switch. The conference table might be too small a boundary to provide good bass.
2. Run the mics into a gated mixer so that only one mic is on at a time. This will reduce the pickup of
room reverb, giving a more intimate sound.
MIKING HARP AND DULCIMER WITH A SASS
Gary Wakenhut of The Collecting Consort records his own albums using a Crown SASS stereo microphone. Formerly Gary was using two GLM-100 microphones. He was happy with them, but was
really impressed when he tried a SASS-P MKII.
“The pickup is exquisite. There’s more clarity, a more clean and open sound, and a natural stereo
spread.”
“I mic the harp and dulcimer overhead with the SASS. Placement is 4 inches from an 8-foot-high
ceiling. Since the SASS picks up more harp pluck than the GLM, I need to mic farther away. The mic
is 3 to 4 feet over the instruments, and picks up a lot of room sound. I reduce the room reverb by
hanging a quilt horizontally near the ceiling.
“I built a wooden platform for the harp, which gives a nice, natural boost to its low frequencies.”
PZM: AN EXCELLENT MIC FOR PIANO
In an interview in the March ’94 EQ magazine, recording engineer Kooster McAllister had this to say
about miking a piano with Crown PZMs:
“A lot of times I have to mic a grand or a baby grand piano in a rock & roll environment, which means
that I have to keep the lid closed.
Fig. 5. PZM piano miking.
“I take a PZM up to the hammers of the piano and tape it onto the lid to get the attack. Sometimes
you have to screw around a little bit with the phase to get it to where everything is working right, but
generally it’s a trick that works for me — a pair of [AKG] 414’s [farther from the hammers] and a PZM,
and I’m pretty happy with what I get on the piano.”
RECORDING A CHURCH SERVICE WITH A SASS
As soundman for his church, Jim Riley wanted to record the service so the musicians could hear how
they sounded in the audience. That is, he wanted to record the output of the sound-reinforcement
speakers.
First Jim placed a SASS near the front row of the audience. But then the mic was off-axis to the
horns when placed this close to the stage. The result was a dull sound. What’s more, the ceiling was
only 10 feet high. Mic placement near the ceiling gave a boomy or bassy sound.
Next, Jim placed the SASS in the back of the church near his mixing position. He noted that the
SASS recording was much more reverberant and bassy than what he heard live in the same spot.
This occurs with any microphone recording. When we hear with two ears, we hear reverberation all
around us, but we hear the direct sound up front. So we can ignore the reverb and concentrate on the
direct sound. But a microphone can’t discriminate spatially between direct sound and reverb. During
playback of a microphone recording, all the reverb is heard up front between the playback speakers,
mixed with the direct sound. That’s why the playback sounds more reverberant or muddy than what
you hear live.
The solution is to place the mic closer to the sound source than where you are listening — about 2/5
the distance. Then the recording will have the same amount of subjective reverb as what you hear
live.
So, we suggested that Jim place the SASS as close as possible to the front where it still picks up the
horns clearly — maybe off-center, in front of one speaker. On the mixer, roll off any excess bass
caused by too much reverb or ceiling placement.
HOW TO MIC A TABLE OVERHEAD
Suppose you’re trying to mic a group of people at a conference table, but no mics can be visible on
the table top. Try these suggestions:
Fig. 6. Table overhead miking.
*Mount a PCC-160 on the ceiling near the table. Put the PCC not directly over the table, but outside it
aiming at the table. Then the table will be more on-axis to the mic.
*Mount a PZM-6D directly over the table. Use two mics for long tables.
*Hang a CM-30 or CM-31 supercardioid mic over the table.
LETTERS FROM CROWN MICROPHONE USERS
SASS dynamics and sonic balance
I’ve been recording with a SASS-P, two PZM-6Rs or 6-Ds, and a DAT. The sound is very good except
for two problems:
(1) When I record a symphonic band, the loud percussion hits are too loud.
(2) When I record a piano/vocal recital, the piano is too loud relative to the vocalist.
I don’t hear these effects when I listen directly to the musical ensembles. How can I solve these
problems?
Reply: To tame the percussive hits, try using a compressor. It will leave the quiet percussive notes
alone, but will soften the loud impacts.Plug your SASS into a mic preamp or mic mixer to bring the
signal upto line level. Plug the preamp or mixer output into the compressor, and plug the compressor
output into your DAT.
On the compressor, try these settings as a beginning: Attack time: very fast (about 1 msec)
Release time: fast (about .1 sec) Threshold: -6 dB. (Set it so the compression starts working at about
-6 dB on your DAT meters).
Compression ratio: 1:4.
To control the vocal/piano balance, try placing a mic of your choice about 3 feet from the singer, and
mix it with a distant SASS mic. The SASS will pick up mainly piano and ambience. Pan the spot mic
to the center, and pan the SASS hard left and right.
Waterproof PZM
I want to pick up the sound of a waterfall in my backyard and reproduce the sound indoors. I plan to
use a PZM-30D near the waterfall. How can I make the mic waterproof?
Bruce Garrett
Reply: Wrap the mic in a thin plastic sandwich bag or plastic wrap. The wrap should be limp, rather
than stretched tight (Tight wrap degrades the frequency response).
Try to put the mic in a shady spot or cover it with an umbrella to keep off sunlight and rain.
You might want to record the mic’s signal during the summer and play it back in the winter.
###
MIC MEMO
Fall 1994
Bruce Bartlett, Editor
JANET JACKSON TOURS WITH CROWN CM-311/E HEADWORN MIC
Superstar Janet Jackson sang through a Crown CM-311/E headworn mic on her world tour. The July
issues of Mix and Pro Sound News reported the news. Jackson wore Future Sonics Ear Monitors and
a Crown Differoid headset mic, which was run through a wireless transmitter.
CM-311/E
According to Showco’s Robert “Cubby” Colby, who mixed the house sound for part of the tour, “Janet
was particularly concerned that she’s a very soft-spoken person, and was concerned about getting
enough vocal headroom above the dance mix, which is fairly big.”
“I wanted to come up with something that was really effective for the headset mic, and I chose the
Crown CM-311/E Differoid mic. I really like the microphone; it’s really robust, darned rugged, and so
far it’s holding up really well for us.”
Showco monitor engineer Randy Bryant said that the headset/in-ear monitor combination works for
Jackson “because she has to dance so much and move around. The microphone is good because
they designed it so that it’s really tight underneath her chin, so when she does the movement, it
doesn’t move either. Other products fit, but they don’t handle the shaking that she gives it with her
dance moves.”
JAZZSET USES PZMs ON PIANO
JazzSet, a weekly hour-long radio program heard on 201 NPR affiliates, features live recordings of top
jazz performers in venues around the country. Branford Marsalis is the program’s host.
Tony Caporale of A-1 Audio, Las Vegas, used a Crown PZM on the piano when he recorded a segment for JazzSet at Caesar’s Palace.
CM-312 HEADWORN MIC WORKS FOR PUPPETEERS
How do you mike a puppeteer? A headworn mic seems to be a good choice because it leaves the
user’s hands free, and the gain is much better than with a lavalier mic.
CM-312
A group of puppeteers called The Information Theater group (from Kaiser Medical) tried a variety of
headworn mics. They wear large puppet heads or masks, and inside the masks they wear headworn
mics so they can be heard by large crowds.
The group tried several brands of headworn mics, but they liked the CM-312/E the best [now the CM312A/E]. “The audio quality was exceptional, and the fit was the best,” said a member of the troupe.
BEAUTIFUL ACOUSTIC RECORDINGS WITH THE SASS-P MKII
If you need to relax, give these new CDs a listen: A Celtic Portrait and All Through the Night by The
Collecting Consort. The group consists of Anne and Gary Wakenhut, who play harp and dulcimer
with a gentle touch. Other artists add flute, clarinet, oboe, and harmonium.
The CDs were recorded entirely with a single Crown SASS-P MKII stereo microphone. Gary
Wakenhut describes his recording techniques:
“The mic was placed about 3 feet above the instruments facing down. The instruments were separated about 6 feet. Flutes, whistles and clarinet were 15 to 20 feet away. The harmonium was about
25 feet away covered in six sleeping bags.
Fig. 1. SASS miking for Celtic Portrait.
“I fastened a quilt to the ceiling directly above the instruments and raised the mic as close to the quilt
as possible. [This distant miking helped us] lose most of the percussive edge from the harp and
dulcimer. So we could work more with expression and be more aggressive with our instruments.
“WBLV, Blue Lake Fine Arts Radio, came here to tape a live broadcast, and we used my equipment.
Steve Albert, the producer, was so amazed by our sound that he immdediately went back to the station to put in a request for the SASS.
“I wouldn’t trade the SASS for all the different models which are available. The SASS gives so much
more of a natural sound and better separation. Since it works like the human ear, mic placement is
not nearly as critical. So I can work more on my musical sound and not worry about the technical
aspects of the pickup.
“The beauty of this mic is its capacity to catch everything. When we add another musician, we just
record an initial mic check, listen to a playback and move the musician a few feet. A second check
usually affirms our assumptions, and we are ready to record. Then it’s up to the musicians to listen to
each other and create their own balance. If the balance is not perfect, the natural essence of the
SASS plays that down much more than traditional recording mics.
“In that respect, even a musician unseasoned in mic choice or placement could achieve a good recording with the SASS. All you need are pair of ears which can get the SASS in the general vicinity of
a good sound. Also, the SASS would be ideal for live work where there is no chance for a mic placement rehearsal.”
If you’d like to hear the Wakenhuts’ recordings, they are available for $14.16 each ($9.44 for cassette)
plus $3.00 postage and handling from The Collecting Consort, 7363 W. Edgar Ed., Lakeview, MI
48850.
MIKING THE TURTLE ISLAND STRING QUARTET
by Darol Anger, a member of the Quartet
The Turtle Island String Quartet has used Crown GLM-100’s from its first concerts. [Although they are
omni mics, they] work best for us because the mics are mounted so close to the instruments. There’s
no proximity effect (as there would be with a cardioid pattern), and the mics strongly pick up the box,
strings, and air around the instruments in pleasing proportions.
We don’t have feedback problems because the mics are so flat in their response and are mounted so
tight in. They are between the strings and the top on the violins and cello, and directly behind the
bridge on the viola.
Crown mic engineers recently made us a batch of GLM-100’s without the high-frequency bump, which
sound even better for the violins especially. The cello seems to do well with the normal lavalier EQ,
however, because of the cello’s lower range.
The problems you get amplifying a cello are similar to guitar problems, and our solutions are similar:
a combination of mic and pickup. The cello mic is centered directly under the strings at the top of the
underside of the bridge’s arch. An L.R. Baggs pickup is in the bridge, and is EQ’d to reproduce frequencies only below 300 Hz. Generally, the pickup is used only when Mark is playing pizzicato bass
lines. The mic is on all the time, getting the normal tone of the instrument.
One of the bonuses of the Crown mics is their toughness. The quartet plays all kinds of venues,
outdoors, funky clubs, and concert halls of every size. These mics have been nearly trouble-free
during the nine years we’ve been gigging.
SASS-P MKII RECORDS FUSION, ROCK & REGGAE
Ward Kremer, a recording engineer with Hole in the Roof Studios, made good use of the Crown
SASS-P MKII stereo mic recently in recording three albums.
He taped Randy Bernsen’s fusion band live with just one SASS. At at outdoor concert, the mic was
placed in a quiet spot between the floor monitors and the house speakers. Kremer used Ampex tube
mic preamps. Although the mic picked up the band at a distance, the recording sounds tight and
almost close-miked.
Ward Kremer with his tube mic preamps.
On Cedrick Luces’ reggae album, “Ready to Parti,” the SASS was mixed with an RCA77DX for lead
vocal, Neumann U67 for percussion, and RCA 77 for steel drums. Kremer used the same setup with
the doo-wop group, Legacy, on their album “A Life Song.”
Kremer reports, “I was very impressed with the overall performance of the SASS, espeically the lifelike
stereo. The detail is excellent even when compared to mics like 77’s and U67’s. The musicians loved
the sound of it.”
Sometimes Kremer placed the SASS over a drum set for stereo pickup. This same setup was employed with fine results at the Elkhart Jazz Festival this summer.
MIKING POP-MUSIC CONCERTS ON TV
Each year, WNIT-TV in Elkhart, Indiana produces a series of music shows called “Across the Dial.”
The series features local musical groups playing jazz, folk, blues, rock and reggae. The instruments
and vocals are picked up with Crown microphones, and are mixed live to video tape for later broadcast.
These mic assignments sounded especially good:
Drum set: One GLM-100 mini mic in the center of the set, clipped to the snare drum rim. If the set
has extra floor toms, another GLM goes between them. Typical EQ is +6 dB at 80 Hz and 0 to +15 dB
at 10 kHz. The louder the music, the more high-frequency boost is needed.
Kick drum: GLM-100 mini mic hanging through the vent hole, near
the center of the drum shell. A pillow damps the beater head.
Typical EQ is -4 dB at 400 Hz to remove the “cardboard” sound,
and +8 dB at 3 kHz for attack.
Vibes: CM-200A about 1 1/2 feet over the top.
String bass: CM-200A 5" from the strings and 3" above the bridge.
Vocals: CM-200A with foam windscreen, lips touching, and EQ’d about -6 dB at 60 Hz to reduce
proximity effect and breath pops.
Guitar amp: CM-200A near the center of the speaker cone.
Bass guitar and keyboards: Direct box.
Acoustic guitar: GLM-200 with bass boost disabled, in the sound hole under the strings. This
sounds natural and has excellent isolation.
Grand piano: Two GLM-100’s taped to the underside of the piano lid, 1 foot apart and 8 inches from
the hammers. Typical EQ is + 6 dB at 10 kHz for extra attack.
###
MIC MEMO
Winter 1995
Bruce Bartlett, Editor
CROWN CM-312 VOTED BEST HEADWORN MIC
Mic Memo editor, Bruce Bartlett, wearing a CM-312 microphone.
Angel City Voice, a trade journal for singers, ran a review of several headworn mics in its Nov. ’94
issue. A panel of five listeners ruthlessly tested four major-name mics for sound, comfort, security,
and ruggedness. The results:
“The Crown CM-312 had by far the best sound, rivaling good handheld mics. The panel says: Unanimous Winner.” Rating: 5 stars. [The current model is the CM-312A.]
“Sound: very full with great presence and crisp highs. Comfort: secure and comfy on larger heads
when adjusted. Quality: very well made. Survived amplifier crush test, then I had to drive my car over
it three times to kill it. Panel comments: Joel — Hot mic, clear highs, easy to set up. Jennifer —
design doesn’t work well with big hair. Matthew — the obvious choice.”
MIKING AND BIKING
Here’s a novel way to carry mics into the wild to record environmental sounds. Matt Lesco rides to the
location on his mountain bike, carrying mics and DAT recorders. When he stops, his bike serves as a
tripod stand for the microphones.
Matt is using a Crown SASS-P MKII stereo mic and two PZM-6Ds. The SASS aims to the front while
the PZMs aim to the rear. He records each mic pair into a separate DAT for later syncing.
PZM-11 FOR VOICE RECOGNITION
The PZM-11 security and surveillance mic can work well for computer voice recognition. Run one or
more PZM-11’s into a mixer. Run the mixer output to a sound card in your computer. Have your
computer run a voice-recognition program that analyzes the signal from the sound card.
POLARITY VS. PHASE
In an article by Travis Ludwig in the Summer 1994 Mic Memo, the author says, “If feedback seems to
be a problem, try putting every other vocal mic out-of-phase with the next.”
Jim Brown of Audio Systems Group wrote in to say, “How much out of phase? At what frequency?
Do you mean polarity?”
The answer is: 180 degrees out-of-phase at all frequencies. The term “out-of-phase” has long been
used, incorrectly, to mean “opposite polarity.” I believe that was the writer’s intent.
In the same issue, we quote recording engineer Kooster McAllister about miking a piano with Crown
PZMs: “Sometimes you have to screw around a little bit with the phase [of the mics] to get it to where
everything is working right.” By “phase,” McAllister either meant polarity, or he meant phase shift
between mic pairs. He used two pairs of mics to pick up the piano — PZMs and AKG 414s. The
spacing between the mic pairs determine the phase shift vs. frequency between their signals.
MIKING AN UPRIGHT PIANO
In the Crown Microphone Application Guide, we suggested this method for miking an upright piano:
Remove the cover to expose the strings under the keyboard. Hang two GLM-100’s near the strings:
one about 8" from the bass strings and one about 8" from the treble strings.
In this position, however, the mics can pick up foot taps and pedal squeaks. You might try miking the
upright over the open top with two GLM-100’s. Piano recording expert Richard Shomin suggests this
method:
Fig. 1. Miking an upright piano over the top.
“My upright technique begins with the piano at 17 degrees from the wall. While adjusting that angle, I
listen for resonances and low-bass balance with respect to the rest of the scale. A piano against the
wall] has thin bass and a natural undesirable resonance.
“I remove the top lid and upper panel. The mics are above and slightly to the front of the piano. I
adjust mic height and frontal position so that the scale is as uniform as possible.
“I generally use a pseudo-binaural mic configuration. The mic tips are separated from 8" to 16" depending on what I am recording and at what distance. The mics are angled apart 60 to 90 degrees to
control the center treble energy. Angling the mics reduces the center hot spot and provides more
even coverage.
Sometimes Shomin records off the sound board rear, with the sound board aiming into the room. “No
detail is lost in rear locations, and this placement usually results in less mechanical noise, such as
hammer action and damping.”
Shomin tries not to pick up room ambience. He feels that room reverb colors the sound and reduces
contrast and resolution.
If you use GLM-100’s, you can get a crisper attack by boosting a few dB at 10 kHz.
REDUCING RFI
Are you hearing a radio or TV station on your sound system? The problem is Radio Frequency Interference (RFI). Sometimes, radio and TV signals get into microphones and their cables, then are
rectified so that the broadcast audio can be heard.
Here are three ways to reduce RFI:
1. Filter it out with capacitors and ferrite beads.
2. Shield it by grounding the XLR connector shells.
3. Use low-impedance, balanced cables wherever possible.
Most Crown mics have RFI filters built in. If you want to add more filtering in the mic connector, try a
0.01 microfarad ceramic capacitor between pins 2 and 1, and between pins 3 and 1. The larger the
capacitor value, the better it filters RFI; but too large a value rolls off the treble in the mic signal. First
try these capacitors on either end of the mic cable — mic end or mixer end. If RFI is still a problem,
put capacitors on both ends of the mic cable.
XLR connector shells do not shield against RFI unless they are grounded to pin 1. So connect pin 1
to the ground lug in the 3-pin XLR connector.
The Crown CM-30 and CM-31 mics have long runs of medium-impedance, unbalanced cable coming
from the mic. If possible, cut this run as short as possible, connect it to the mic’s power module, then
run the low-Z alanced signal from the module back to your mixer.
LETTERS FROM CROWN MIC USERS
PZM-11 is a work of art
Enclosed is a photo of our installation infrastructures that was at the Center of Contempory Art from
June 25 to August 13, 1994. The photo shows one of the nine Crown PZM-11 mics highlighted on the
back wall.
PZM-11 (highlighted) as part of a work of art.
The following text was included in the catalog for our piece:
“The collaborative team of David Galbraith and Teresa Seemann create a distributed yet collapsed
electronic, architectural and acoustical space in their sight-specific piece entitled infrastructures. The
piece investigates constructed environments through the architecturally embedded exchange of raw
unformed AC power for the coded flow of electronic speech and sound.
“Special thanks to... Crown International, Mackie Designs, Symetrix, and Lone Wolf for their unique
contributions.”
Thank you very much for supporting our art work. The show was very successful and received a
number of positive reviews in the local press.
David Galbraith, Teresa Seeman, Lone Wolf Corp.
Recycled paper
I would like to suggest printing the Mic Memo newsletter on recycled or at least recyclable paper. I
find the newsletter very informative.
Keep up the good work!
Doug Krehbiel, Road Less Traveled, White Pigeon, MI
Reply: Thanks for the idea, Doug. We’ll look into it.
GLM shock mounting
I’m using GLM-200’s for horns, strings and percussion. However, the horn mount does not isolate the
mic very well when used on a sax. You get a lot of thumping from valve action even with a lot of low
frequencies EQ’d out. Any solution?
Reply: Try the arrangement shown in Fig. 2. Using the GLM-HM Horn Mount, clamp onto the GLM
cable 2 inches from the mic. Put a fishing weight on the GLM cable near the clip, on the mic side of
the clip. This arrangement makes the mic floppy so that it’s shock-isolated by its cable.
Fig. 2. GLM-200 shock mounting.
PZM for amateur radio
How about offering a PZM for the amateur radio hobby?
S.H. Kundin
Toms Reiver, NJ
Reply: We’re looking into modifying the PCC-170 cardioid boundary mic. It would have a button for
external switch closure, such as used with an amateur radio rig.
Demo CD
Ever consider a cassette or CD of “What does it sound like if...” It would have information on using
Crown mics and would give audible examples of situation changes. An excellent case study is in the
Spring ’94 issue, “How to reduce reverb with a PZM Wedge.”
Also, I’d love to hear examples of SASS sound. Didn’t you offer a CD a few years ago? Is it still
available?
R.C. Hauf
RCH Productions
Upper Montclair, NJ
Reply: There was a SASS demo CD but it is no longer available – sorry. However, most Crown
dealers will do a free loan for trial. A Crown mic demo CD is in the works. [currently available]
Overhead miking not for P.A.
In a recent Mic Memo is an article, “How to mic a table overhead.” It showed a Crown CM-30 mini
supercardioid hanging over a table. I am certain that this technique will work for recording (if the airconditioning system is quiet). But for sound reinforcement or teleconferencing, this distant placement
is unlikely to work (as predicted by the potential acoustic gain equation).
Please tell your readers when a mic technique is only for recording. Mics on the ceiling have virtually
no chance of working for sound reinforcement.
Michael Petterson, Shure Brothers Inc.
Book of mic tips
I would like to see all the miking suggestions from past newsletters in book form.
David Exon
Toronto, Ontario, Canada
Reply: Another super idea. A few years ago, we gathered the best tips from the Mic Memo and put
them in booklets. These mic-technique application guides are available free from Crown or your
Crown dealer:
*Crown Microphone Application Guide (for CM, LM, and GLM mics)
*Boundary (PZM, PCC and SASS)
*Schools
*Houses of Worship
*Video
*Teleconferencing and Distance Learning
*Studio
*Speech Sound Reinforcement
*Security and Surveillance
PZM-11LL for observation rooms
Figure 3 shows a way to pick up conversation in a psychiatric observation room. This suggestion is
from reader Martin Philip. A Crown PZM-11LL line-level PZM mic sends its audio signal into a separate listening room, where students and their instructor wear receivers.
Fig. 3. PZM-11LL listening system.
PZM stereo miking
I have been using PZM-30D’s for about six years, mostly recording our large vocal and symphonic
groups. I like to mount the mics on a large flat surface above the groups, left and right, then pan the
signals to opposite sides for a pseudo-stereo effect. The slight delay fattens up the sound as though
you were right where the conductor is standing.
Dan Greuter, E. Peoria, IL
###
MIC MEMO
Spring 1995
Bruce Bartlett, Editor
FOUR NEW MICS FROM CROWN
We’re happy to introduce four new microphones:
CM-200ASW: Same as the CM-200A handheld cardioid, but with an on-off switch.
CM-310ASW: Same as the CM-310A Differoid, but with an on-off switch and adjustable frequency
response.
CM-311HS: Same as the CM-311 Differoid headworn mic, but attaches to a Sony MDR-7506 headphone.
CM-311HS
CM-312HS: Same as the CM-312 hyper-cardioid headworn mic, but attaches to a Sony MDR-7506
headphone.
Let’s look more closely at each product.
The Crown CM-200ASW is a cardioid condenser mic for provocal/instrumental use. It offers studioquality sound, yet is rugged enough to withstand hard use in the field. It looks great, sounds great,
and has a good balance in the hand. A built-in magnetic reed switch turns the mic on and off. The
smooth-acting switch works silently.
The Crown CM-310ASW Differoid is a handheld noise-canceling mic for sporting events or other
applications with high ambient sound level. It features a magnetic reed switch that turns the mic on
and off.
The CM-310ASW uses Crown’s patented Differoid technology. It is differential or noise cancelling, so
it rejects sounds that are not close to the microphone. It has a cardioid polar pattern, so it rejects
sounds from the rear.
These features give the CM-310ASW exceptional gain before feedback. It permits extremely loud
P.A. levels before feedback occurs. The mic also rejects unwanted background noise. The announcer can sit in the stands with the audience, with the P.A. speakers playing loudly, and not run into
feedback.
Inside the mic handle, on the circuit board, is a dip switch that sets the frequency response. It has
two positions: music and announcing. The music position sounds warm and smooth, while the announcing position has less bass and more highs for extra intelligibility.
Designed for broadcasters, the Crown CM-311HS is a rugged head-worn microphone that mounts on
a Sony MDR-7506 or MDR-V6 headphone. The mic rejects background noise extremely well, so it’s
well-suited for use in traffic-copters, sporting events, or car races.
The CM-311HS is the latest version of Crown’s patented Differoid technology. Its a cardioid, so it
rejects noise from behind the mic. And it’s noise canceling, so it rejects ambient noise. Lightweight
and comfortable, the mic adjusts to fit any user. Supplied with the microphone is a battery/phantom
belt pack with a mute button.
The Crown CM-312HS is a rugged, lightweight head-worn microphone that mounts on a Sony MDR7506 or MDR-V6 headphone. Some applications are radio and TV sports broadcasts, and radio
studio announcing.
Because the microphone is to the side of the mouth, the mic looks inconspicuous and does not pick
up breath pops. The sound of the CM-312HS can be tailored to taste by moving the microphone
closer or farther from the corner of the mouth.
The CM-312HS sounds like the best handheld microphones. Its hyper-cardioid pickup pattern reduces feedback and aids isolation. In difficult situations, the Crown CM-311HS head-worn mic is
recommended because it picks up even less feedback and leakage than the CM-312HS. The mic
adjusts to fit any user. Supplied with the microphone is a battery/phantom belt pack with a mute
button.
A SIMPLE MIC SPLITTER
When you record a pop-music concert, three mixers are in use: recording, PA, and monitor. So you
need to split each mic’s signal three ways to feed the three mixers.
One way is to use a transformer isolated splitter (Fig. 1). Each mic plugs into an XLR that goes to a
1:1 transformer. The splitter has three feeds: one direct and two isolated. Connected directly to the
mic, the direct feed goes to the mixer that supplies phantom power.
Fig. 1 Transformer-isolated splitter.
The two isolated feeds go to the other mixers. Since the transformer electrically isolates the three
mixers, phantom power and RFI from one mixer can’t get into the other mixers.
Unfortunately, good transformers cost a lot. You can make a splitter without transformers that works
well. Simply Y or parallel the mic output into three mixer inputs. This works, but it creates some
problems.
First, the three mixers load down the mic. The mic-input impedance of a typical mixer is 1500 ohms.
The paralleled input impedance of three mixers would be only 500 ohms. This is too small a value for
many mics. With this load, some condenser mics distort, and dynamics tend to lose some bass.
Another problem is that the Y connects the three mixer grounds together. This can create ground
loops and hum.
Figure 2 shows a solution. The mic signal runs through two 270 ohm resistors before splitting. The
resistors prevent the mic from loading down. Each mic sees about 1040 ohms, which is usually high
enough to prevent distortion and tonal changes. With the resistors, the loss is only 3 dB compared to
a 3-way Y splitter. Each mixer sees a source impedance of about 384 ohms, which is low enough to
keep the noise down.
Fig. 2. Resistor-isolated splitter.
To prevent ground loops, only one feed is grounded to the mic-cable shield. This feed goes to the
mixer that supplies phantom. The pin-1 ground on the other two mixer feeds is floating. Each mic
cable leaving the splitter is grounded at its own mixer to drain away hum interference.
A drawback of the resistors is that they increase the high-frequency loss of the cables due to capacitive loading. But this loss may not be audible.
Don’t ground the splitter chassis. Why? If someone plugs in a cable connector that has its shell tied
to pin 1, the mic will be grounded through the splitter chassis to more than one mixer. You’ll get a
ground loop. Instead, use shielded mic cable inside the ungrounded chassis. Connect the shields as
shown in Figure 3. Note that the shield is floating at two of the male XLRs to prevent ground loops.
The transformer-isolated splitter in Figure 2 has ground-lift switches that do the same thing. You can
add these switches to the passive splitter if you need more flexibility.
Does the transformer isolation prevent the mic from loading down? Nope. Each transformer winding
is 1:1, so the reflected impedance that appears at the primary is the input impedance of three mixers
in parallel. The mic sees about 500 ohms. You still need to add the 270-ohm resistors to the transformer isolated splitter.
Another way to reduce loading is to use a step-down transformer. Although this loses a few dB of
signal level, it raises the impedance seen by the mic.
MIKING A FLUTE WITH A HEADWORN MIC
At the January NAMM show, a flutist was looking for a way to mike his flute. He tried on a Crown CM311 headworn mic. Then, by bending the wire that was behind his ear, he adjusted the boom to place
the mic slightly above and in front of the lip plate (Fig. 3). (Some head sizes will preclude such a
boom adjustment.) This flute pickup sounded so good, he bought the mic!
Fig. 3. Flute miking with a CM-311.
MIKING A KIOSK
Sound engineers at Disney World wanted to mount a mic in a videogame kiosk (booth) to pick up the
voice of the player. The mic had to be hidden to prevent damage.
We suggested that they mount an LM-300A super-cardioid lectern mic inside a damped enclosure
covered with perforated metal. Figure 4 (top) shows the response of the LM-300A in open air at 0
degrees, 90 degrees, and 125 degrees sound incidence. Figure 4 (bottom) is the same with the mic
mounted in a 6" x 6" x 4-1/2" deep cardboard enclosure covered with a 1/16" thick perf-metal grille.
Fig. 4. Top: LM-300A in open space. Bottom: LM-300A in enclosure.
To reduce resonances, the enclosure is covered inside with 2" thick Sonex foam. The mic still retains
much of its directionality inside the enclosure. Since the perf metal is at least 40% open, it is transparent to the incoming sound.
NOVEL PCC MIKING WORKS GREAT
Charles Mangano, a sound engineer in Frederick, Maryland, showed us a unique way to mike a theater stage with three PCCs. One mic is at the front edge of the stage in the center. It aims at a
couch. On either side of the couch are two PCCs aiming left and right. “It worked like a charm,” said
Charles. He reduced floor squeaks by putting a thin foam pad under each mic.
PCC LEVEL VS. ACTOR POSITION
Ever wonder how much the output level of a PCC varies when an actor moves around on stage?
Figure 5 shows the mic’s calculated output level for various actor positions. The level of an actor 10
feet in front of the mic is called “0 dB.” The levels at other positions are referenced to that.
Fig. 5. Actor’s level in dB vs. position as reproduced by a PCC-160.
The closer an actor is to the PCC, the higher is its output due to the inverse square law. However, the
closer an actor is to the PCC, the more off-axis he or she is to the mic, so the output level tends to
drop as the actor gets closer. The two effects partly cancel out, so the PCC’s output level is fairly
uniform no matter where the actor stands.
One mic can cover a stage 17.4 feet wide, because the level is 3 dB down at the edges of the stage.
Two mics 20 feet apart can cover a stage 40 feet wide. If both mics are on, and an actor is midway
between them, the actor’s level goes up 3 dB.
SASS “AWESOME” ON DRUMS AND JAZZ TRIO
Ward Kremer, a recording engineer in Fort Lauderdale, has been using a SASS-P MKII stereo PZM
on drum sets. He puts the SASS about 3 feet in front of the set, 5 1/2 feet high, and tilted down a
little. Sometimes he adds a kick-drum mic. He boosts EQ a few dB around 10 kHz to bring out the
cymbals.
The results? “I’m getting the best drum sound I’ve ever gotten,” says Kremer. “People who have
heard the tapes say, ‘Man, what is that? That’s the best drums I ever heard.’ The left-to-right imaging is supreme. The stereo honesty gives it the 90’s sound.”
Kremer recorded a jazz-fusion trio in a long, narrow jazz coffeehouse. The SASS was 4 feet off the
floor. According to Kremer, the tape needed no changes. “It’s got class... an intimate yet mellow live
sound.”
“The band was very loud — 120 dB average level — but the recordings are so clean. Their dynamics
are just awesome.”
“Using the SASS is so much easier and better than multi-miking. For one thing, my $20,000 worth of
vintage tube mics are not safe to take on location, but the SASS is rugged enough to take in a night
club. It’s affordable and really simple to operate.”
LETTERS FROM CROWN MIC USERS
Violin miking with GLMs
Having just finished the Fall 1994 Mic Memo, I would like to offer my support for Darol Anger’s recommendation regarding the GLM-100. For the past year I have been miking my strings in this fashion
with excellent results.
My use of the GLM-100 is for violins and violas in a live orchestra which varies from 26 to 30 instruments. As is too often the case, especially in churches, the brass and woodwind sections are much
stronger than the string section. On several occasions I have had as few as two violins and one viola.
This orchestra plays in a wonderfully live sanctuary (acoustical consulting provided by my company, of
course). The Minister of Music does not like to mike the orchestra at all. His concern (and I agree) is
the unnatural localization of the sound when the strings are heard coming from the center cluster
above the orchestra.
To overcome this problem, I plug the GLMs directly into an Anchor Audio model MPB-4500 portable
speaker system. I locate the speaker at the feet of the first-chair violin player. She has been trained
to adjust the volume as directed by the Minister of Music.
Although the GLM-100 is an omni, the body of the violin and viola shield the mic enough to allow
sufficient sound pressure level prior to feedback to please the director. The result is a rich, warm
sound, sufficient to balance with the brass and woodwinds, while still originating from the correct
location within the orchestra.
Bob Adams
Hoover & Keith Inc.
Houston, TX
###
MIC MEMO
Summer 1995
Bruce Bartlett, Editor
SASS ON CD GIVES AUDIOPHILE SOUND
Epiphany Records engineer, Jeremy Kipnis, used a custom Crown SASS-P MKII exclusively to record
two audiophile CDs. One is a recording of Beethoven works played on a fortepiano; the other is a
baroque chamber trio (Fig. 1). Both are 24-bit digital recordings.
Fig. 1. Ephiphany EP-2.
The sound got rave reviews. As Robert Deutsch said in Stereophile, Nov. 1994, “This lovely recording features impeccable musicianship and exceptionally natural sound (EP-2, The Instrument of
Kings.)”
According to Epiphany’s press release, “Epiphany Recordings brings the listener closer than ever
before to the experience of a live concert... Epiphany’s unique recording system uses the most advanced technology available, including a single stereo microphone [Crown SASS-P MKII] created
especially for Epiphany Recordings...”
The customized SASS has these special features:
*Mic capsules acoustically tuned for desired timbre.
*Bipolar battery power supply for each capsule.
*Point-to-point internal circuit wiring with silver solder.
*Cardas oxygen-free copper Litz wire.
*A metal film resistor and a hand-wound metal film capacitor are the only circuit components.
*Battery power supply not referenced to mic preamp.
*Independent shielding for each capsule, power supply and ground plane.
*SASS housing treated with vibration-absorbing putty.
*Mic stand filled with #25 lead shot and tuned to 7.48 Hz.
Epiphany describes the CDs:
Epiphany EP-1: The Young Beethoven. “Igor Kipnis performs the Moonlight andPathetique Sonatas
and other Beethoven works on his 1793 Graebner fortepiano, an instrument of the type the composer
knew and played during his earlier years. Kipnis’s interpretation is as stylistically and historically
informed as one can find anywhere today.”
Epiphany EP-2: The Instrument of Kings.
“Flutist John Solum, using two period instruments, performs baroque and classical sonatas by Handel,
Domenico Scarlatti, Vinci, Telemann, C.P.E. and J.C. Bach, and Mozart with harpsichordist and
fortepianist Igor Kipnis. Arthur Fiacco, cellist provides continuo [continuo is correct spelling] accompaniments in the baroque works.”
We’re proud that Jeremy chose the Crown SASS to make recordings for his audiophile label.
HOW TO ATTACH A GLM-200 TO A BOOM
Many mic users want to mount a GLM-200 mini hyper-cardioid mic over a drum set, or in front of a
choir. Here’s a low-tech method to attach the GLM-200 to a mic-stand boom:
1. Tape a GLM-SM Surface Mount to the end of the boom.
2. Cover the end of the boom with tape so the mic doesn’t pick up boom resonances.
3. Insert the mic in the Surface Mount.
GLM VIOLIN MIKING
Fig. 2. GLM violin miking.
Fig. 3. GLM violin miking.
In the Spring ’95 issue of the Mic Memo, we told about miking violins with the GLM-100 mini omni mic.
Bob Adams used this system for a live orchestra of 26 to 30 players. The amplified GLM signal plays
through a speaker at the feet of the first-chair violinist.
Recently we received some photos from Bob that show the mic placement (Figs. 2 and 3). Note the
GLM-TB Tie Bar, which clips the mic to the violin bridge.
DON’T GROUND XLR SHELLS
In the Winter ’95 issue of the Mic Memo, we printed a misleading statement in an article on reducing
RFI:
“XLR connector shells do not shield against RFI unless they are grounded to pin 1. So connect pin 1
to the ground lug in the 3-pin XLR connector.”
This advice applies only to XLR connectors that never touch any external conductors. An example of
such a connector is an XLR in a hanging cable (Fig. 4). You might use such a cable to hang a mic
over a choir or an orchestra. Grounding the shell in a hanging cable is a last resort against RFI if
other measures fail.
Fig. 4. XLR connectors in a hanging cable.
Generally, you should NOT ground the shell to pin 1. If you do, you can set up ground loops if the
shell touches outlet boxes, wet grass, metal gridwork, and so on. There might even be a shock hazard.
Thanks to Ron Steinberg of RC Communications and John Landphere of Ancha Electronics for pointing out the error. Steinberg offers this advice:
In a mic cable, tie the shield only to pin 1 in each of its XLR connectors. Ground the mic cable only at
its preamp input. Never connect the shell of XLR connectors to shield except within a microphone.
Insulate from their mounting plate any connectors which use their shells as conductors for shield (for
example, 3-circuit, 1/4" phone jacks and BNC connectors).
Many commercially available mic cables and adapters will need their wiring changed to float pin 1 from
the shell.
Steinberg also recommends that PZMs be isolated from conduit ground, since the PZM plate is
grounded via the cable shield.
John Lanphere has this to say: If the shell is grounded to pin 1, and you plug it into a mic jack with an
isolated ground, you no longer have an isolated ground.
According to Lanphere, Gotham makes a cable with a double braided shield and an insulated ground
wire. You tie the shield to pin 1, and tie the XLR connector ground lug to the insulated ground wire.
That way the cable shell is grounded to prevent RFI, but it’s not tied locally to the pin 1 ground.
Lanphere also says that Benchmark makes a very effective inline RFI filter. You can call Benchmark
at 800-262-4675 to get a pamphlet on grounding.
REGIS & KATHIE LEE SHOW RELIES ON SASS STEREO MIC
The Regis & Kathie Lee Show, a popular daily talk show, features lively interaction between the studio
audience and hosts Regis Philbin and Kathie Lee Gifford.
To accuately capture the audience response, the show’s technical staff tried a number of different
microphones and configurations before selecting the Crown SASS-P MKII. They discovered that a
single SASS mic flown centrally above the audience in the show’s 120-seat studio at WABC-TV, New
York does the job — and does it quite well.
Incorporating Crown’s PZM technology, the SASS-P MKII supplies excellent stereo imaging with two
PZM mics mounted on a head-size boundary. The mic is also mono compatible.
“The SASS-P MKII has been able to provide the consistent levels and sound quality we were looking
for,” says Bill Beam, WABC-TV chief engineer. “The audience sounds full and bright, and we’re able
to capture their full reaction.”
DIFFEROID HELPS INDY 500 BROADCAST
The radio broadcast of the annual Indianapolis 500 auto race is heard by millions of people throughout
the world on more than 1,200 stations.
Four announcers — one at each speedway turn — deliver the latest action as race cars rush by at
speeds exceeding 220 mph. Sound quality was always a problem until the announcers began using
Crown CM-311 headworn microphones.
Featuring Differoid capsule technology, the CM-311 provides very high gain-before-feedback, and
rejects unwanted background noise and leakage. Since the Indy 500 announcers began using Crown
CM-311s, overall sound quality and vocal presence are greatly improved, as is noise rejection. Other
Crown mics used at the speedway include a CM-310ASW Differoid for the track PA announcer, and a
CM-230 tridundant mic.
“The bottom line is that we like the Crown approach to microphone design,” says John Royer, chief
engineer for the Speedway and radio network. “The company has a number of products that fit the bill
for typical uses, while also meeting special needs and applications.”
TIPS ON USING CROWN STAGE MICS
We recently posted the following PCC pointers on the Internet:
The PCC-160 floor mic is supercardioid, so it rejects feedback better than the PZM-30D, which is
omni.
One PCC can cover a stage 17 feet wide, because the level is 3 dB down at the edges of the stage.
Two mics 20 feet apart can cover a stage 40 feet wide. Commonly, three mics are used because
much of the action is center stage.
Place the PCCs as close to the actors as possible without getting in their way. This has three benefits:
1. The mics receive a higher SPL, which increases gain before feedback.
2. The mics are farther behind the house speakers, which increases gain before feedback.
3. The mics are farther from the pit orchestra, so they pick up less orchestra.
If you still pick up too much pit orchestra, lay a foam pad on the floor about 1 inch behind the PCC.
Try a 2-foot-square piece of foam or Sonex, about 3 inches thick. Do not put a plexiglass boundary
behind the PCC because it will degrade the frequency response and polar pattern.
Use a 1/3-octave graphic equalizer to notch out frequencies that feed back. Here’s a suggested
procedure:
1. Turn up all the mics equally until the sound system just starts to ring or feed back.
2. Find the EQ knob that affects the feedback frequency, and push it down just to the point where
feedback stops.
3. Turn up the mics a little more until they start to ring again, usually at a different frequency.
4. Find the EQ knob the affects that frequency, and push it down.
5. Repeat this process until you’ve notched out about five feedback frequencies, or until the system is
loud enough without feedback.
After EQ’ing the system, turn up each fader slowly just to the point where feedback occurs. Mark that
point with a piece of tape. Don’t push the fader above that point. Also turn up all the faders equally
and note the point of fader travel where feedback occurs. Mark that point with a piece of tape, and
don’t push the faders above that point.
The fewer mics that are on, the better. One mic has less feedback and clearer sound than two or
more mics.
To prevent feedback during the performance, try to turn up only one mic at a time. Follow the action
with the mixer faders, turning up only the mic closest to the person speaking. When more than one
actor is speaking or singing, you may need to turn up two or three mics. It helps to follow a marked
script.
If there are some scenes where you still can’t hear the actors, you may need to put a mic close to
them. Try a PZM on the set near the performer, hang a CM-31 nearby, or clip a wireless lavalier mic
on the performer. Keep the mic’s fader down until you need to use the mic.
SIMULATING A CAR INTERIOR
Philip Blair suggested this way to simulate a car interior for radio drama: “Tape a spaced pair of PZMs
to the studio window. Hang a hard board, empty tape box, or Perspex sheet in front of each of the
mics. The board is between the mics and the actors. You’ll get a great car interior sound.”
“I’ve also tried PZMs over drum kits. They work really well, and pick up lower frequencies than you’d
expect. They are a bit bright and ‘fizzy’ but that was what I wanted on the day I used them.”
COOL WAY TO MOUNT A GLM-100
David James is a hammer-dulcimer player who has won many musical contests. On stage, he plays
dulcimer, guitar, mandolin, bouzouki, etc. and mikes them all with a Crown GLM-100 mini omni mic.
Rather than mounting several GLMs on all his instruments, David uses a single mic. He glued a small
square of Velcro on the GLM, and another square on the cable to act as a strain relief (Fig. 5). Using
double sided tape, he attached mating squares of Velcro to each instrument.
Fig. 5. Velcro squares on GLM-100.
When David plays guitar, he sticks the GLM on his guitar. Then he removes the mic and sticks it on
his mandolin, and so on. When the mic is not in use, he attaches it to a music stand.
LETTERS FROM CROWN MIC USERS
PCC handles outdoor abuse
I am the new sound designer at Fort Harrod Drama Productions Inc. [We] have produced the outdoor
drama The Legend of Daniel Boone for thirty years. Outdoor drama is very hard on mics. Every year
they sit all summer through rain or shine on a sand stage in the open weather.
I would like to thank you for designing one of the best mics ever made: the Crown PCC-160. [We]
never had the luxury of good sound reinforcement until we bought PCCs two or three years ago.
They have excellent range and are, in my opinion, the ultimate boundary mic for the theatre.
Michael Rasbury
Sound Designer/Composer
Fort Harrod Drama Production, Inc.
Harrodsburg, Kentucky
###
MIC MEMO
Fall 1995
Bruce Bartlett, Editor
NEW CM-700 STUDIO MIC IS CROWN’S FINEST
CM-700
We’re proud to announce our finest studio microphone: the Crown CM-700. It’s a cardioid condenser
mic for pro or semi-pro recording and sound reinforcement.
Rugged enough for the road, the CM-700 is well suited for acoustic instruments, drum overheads, and
studio vocals. It works equally well for popular music (multi-miking) or classical music (stereo and
spot miking). Small and inconspicuous, the CM-700 is also a good choice for miking a lectern.
The CM-700 has a very smooth, wide-range frequency response (30 Hz - 20 kHz) which gives it a
natural sound. It preserves the delicate timbre of acoustic instruments, yet can reproduce all the
power of a pipe organ. The off-axis response is smooth, so any leakage picked up has little coloration.
Because of its cardioid pickup pattern, the CM-700 reduces background noise, room reverb, and
feedback. The cardioid pattern is uniform with frequency.
Self-noise is very low, permitting clean, noise-free recordings. The mic can handle very loud sounds
without distortion. It is protected against static and RFI. The output is balanced, low impedance,
which allows long cable runs without hum pickup or high-frequency loss. Powering is by 12-48V
phantom power.
Several audiophile touches enhance the mic’s pristine sound quality: an ultra-light diaphragm,
humbucking transformer, polycarbonate capacitors, and a gold-plated 3-pin connector.
The CM-700 has a bass-tilt switch with three positions: flat, low-cut, and rolloff. An included 3-stage
foam pop filter softens breath pops, and a foam windscreen reduces wind noise outdoors.
TRY A PCC ON THE CEILING
To pick up a conference in which no mics are allowed on the table, you might try s PCC-160 on the
ceiling. This setup is for recording rather than P.A. The people should be in front of the mic within 30
degrees from the front, as in Figure 1. Aim the “dead” rear of the mic at air-conditioning ducts.
Fig.1. Miking a conference with a PCC-160 on the ceiling.
HOW TO PREVENT PLUG-IN POPS
A drummer told us he was using a Crown CM-311 headworn mic. He wanted to put on the mic in his
dressing room, walk onstage wearing the mic, then plug it into a mic cable by his drum set. The mic
cable supplied phantom power from the P.A.’s mixer. When the drummer plugged in the mic, there
was a loud pop as phantom was applied suddenly. There was no mixer operator to mute the mic.
We suggested, “Build an in-line mute switch. When you walk onstage, close the switch to mute the
mic channel, then plug in the mic, then open the switch. You’ll hear very little pop when you plug in
the mic.”
How does the circuit work? See Fig. 2. When you close the switch, any pop signal between pins 2
and 3 is shorted out. This greatly reduces the pop. Also, the 0.1 uF capacitors partially short any pop
signal that develops between pins 2 and 1, and between pins 3 and 1.
Fig. 2. Microphone mute switch.
PZM WEDGE MAKES BEAUTIFUL RECORDINGS
When National Public Radio (NPR) recently heard some new PZM recordings of choir and orchestra,
they were impressed! They didn’t know that Crown mics could sound so good.
The recordings were done by John Coker, a recording engineer from San Antonio, Texas. He stopped
by Crown one day to play us his recordings made with a PZM wedge.
They sounded so sweet and clear! You could hear every detail, such as triangle hits in a rapid roll, or
snare wires buzzing on a snare drum. Cymbals were crisp yet very smooth. On the low end, the bass
drum and tympani were clean. I liked the pinpoint stereo imaging and the wide sound stage.
Figure 3 shows John’s typical PZM wedge assembly. He has made seven of these boundaries, each
optimized for a different venue.
Fig. 3. A PZM wedge.
The V-shaped part is made of two plexiglass panels, each 1-foot square. Actually, they are a 2-foot
x 1-foot piece bent to the desired angle. “If the angle between panels is too small,” says John, “you
hear all the instruments on the left and right, with nothing in the middle. A wedge angle between 58
and 72 degrees is optimum.”
John mounts a PZM-6 or PZM-30D in the center of each panel.
At the back ends of the V are flanges that screw to a rear panel, which is 2-feet square. The rear
panel blocks sound from the rear of the hall. On the inside of the rear panel is an Atlas 90-degree
mount, used to mount the array to a mic stand.
Typically, John places the PZM array about 24 feet from a band or orchestra, 18 feet from a choir, and
11 to 14 feet from a small ensemble. The mics are raised 14 to 25 feet above the stage floor. John
tries to place the mics at a spot where the distance to the rear of the ensemble is 1.7 times the distance to the front of the ensemble.
John says, “Often I EQ the PZMs -1 dB at 8K, -2 dB at 16K, and +1.5 dB at 20 to 40 Hz. But if the
stage curtains dull the sound of the orchestra, I don’t EQ the mic.”
John had to convince NPR that his recordings were not multi-miked, and were not digitally enhanced.
They had that kind of clarity. Often, just two PZMs are all you need to get presence and detail.
“With multi-miking,” says John, “you can’t get the blend that occurs naturally in the air. PZMs at a
distance let you get that blend, but with the clarity of close miking. A recording made with conventional mics tends to lose ambience. It’s 2-dimensional, not 3-dimensional as with PZMs.”
NEW CM-10 OMNI LAVALIER IS EASY TO USE
CM-10
Crown has been selling the GLM-100 mini omni as a musical instrument mic, and also as a lavalier
mic. When used as a lavalier, the GLM-100 can be tricky to aim because it is side-addressed.
So, we introduced the CM-10: a tiny cylindrical mic that’s easy to aim. It’s an omni condenser lavalier
mic of professional quality. Although the CM-10 costs little, it has a smooth, wide-range frequency
response.
The GLM-100 has a flat response for accurate reproduction of music. In contrast, the CM-10 has a
response tailored just for lavalier use. The response rises at high frequencies to compensate for the
mic being off-axis to the mouth, and rolls off below the voice range to cut out rumble from trucks and
air conditioning.
The mic capsule and its cable are field replaceable.
Included with the mic is a rugged tie mount, which clips securely to the tie or shirt. The mount can be
worn facing left or right for male or female announcers. When the user clips on the tie mount, the
cable can be hidden under clothing. An optional dual clip is available from your dealer for redundant
miking.
Two models are available:
CM-10: Supplied with a tubular power module, powered by phantom power.
CM-10/E: Supplied without a connector, for use with a wireless mic transmitter of your choice.
The CM-10 output is balanced, low impedance, which allows long cable runs without hum pickup or
high-frequency loss. RFI protection is included. The CM-10/E output is unbalanced, medium impedance.
Because of its ruggedness, ease of use and great sound at low cost ($149 list), we feel that the CM10 represents an excellent value.
MICHIGAN HERITAGE CD DISPLAYS SASS MIC VIRTUES
Anne & Gary Wakenhut — two musicians known as the Collecting Consort — have recorded a new
CD using only the Crown SASS-P MKII stereo mic. The CD, “Michigan Heritage’” is a live stereo
recording of harp, dulcimer, flute, fiddle, string bass, whistles, and parlour organ.
The sound quality is natural. In my opinion, the overall tonal balance is just right — not too tinkly.
Harp is full and deep. At normal listening levels, you hear little or no hiss.
There’s a nice airy sense of space, distance and depth, thanks to the natural room reverb that was
captured. The recording sounds like musicians in a room instead of a close-miked band with artificial
reverb added.
The balances among instruments are carefully done, and the music, as always, is restful and very
pleasant.
In setting up to record the CD, Gary Wakenhut applied acoustical foam to the ceiling in an 8' x 8' area
over the instruments. Then he placed the SASS about 5 feet in front of the dulcimer and harp (Fig.4).
The SASS was about 4 feet high, just below the top of the dulcimer. Higher placement picked up too
much hammer sound.
Fig. 4. Harp and dulcimer miking with a SASS.
At first, Anne and Gary pointed the harp directly at the mic. “However,” Gary says, “as we walked
around the instrument, we liked the sound radiating from the side of the instrument better... a better
overall balance of the top and low end of the instrument. But facing the harp at the mic gave a fuller
sound, so that’s what we used.”
“The combination of the [ceiling] foam and the increased miking didstance let us open up our playing.
We could be more expressive, using more volume and dynamics. Also, mechanical sounds were less
of a problem.”
“We placed whistles, flute, and fiddle about 12 to 18 feet away. This gave good presence and helped
balance these louder sounds with the quieter harp and dulcimer.”
Even though the parlour organ was 20 feet away, it was too loud relative to the harp. “We stuffed all
sound-resonating cavities of the beast with fiberglass batting. We surrounded the organ from floor to
ceiling with 1" styrofoam insulation board. On top of this, we hung sleeping bags to further absorb the
sound.”
To isolate the string bass, Gary put it in a far corner, and covered it with styrofoam panels and sleeping bags.
“This recording really surprised our mastering engineer,” says Gary. “He liked the naturalness of the
sound, and remarked that it needed far less reverb and EQ to obtain our desired sound than previous
recordings.”
If you like slow, peaceful music, you’ll like “Michigan Heritage.” It’s available for $16.04 (CD), or
$10.38 (cassette), plus $3.00 shipping from The Collecting Consort, 7363 W. Edgar Rd., Lakeview, MI
48850.
PZM-10 “INVISIBLE” MIC
PZM-10
Here’s a new mic that does a disappearing act. The Crown PZM-10 is a flush-mounted, Pressure
Zone Microphone designed for security, surveillance, and conference-table use. Since the mic looks
like a light switch, it is inconspicuous.
For many users, the PZM-10 is easier to install than the PZM-11, which mounts in an electrical box
and has screw terminal connectors. The PZM-10 mounts in a hole in a ceiling panel or tabletop, and
has an XLR-type connector for easy plug-in installation.
In the PZM-10, low frequencies below the voice range are rolled off to reduce pickup of air conditioning rumble. High frequencies are boosted to aid intelligibility. Because of its tailored repsonse and
PZM construction, the PZM-10 will pick up conversations or other desired sounds with extra clarity
and definition.
The output is balanced, low impedance, which allows long cable runs without hum pickup or highfrequency loss. Powering is by 12 to 48V phantom power.
The mic’s humbucking transformer and steel case prevent hum pickup, even near fluorescent lights.
Frequency response is 80 Hz to 20,000 Hz, and the polar pattern is hemispherical.
###
MIC MEMO
Winter 1996
Bruce Bartlett, Editor
THE PSYCHOLOGY OF MICROPHONES
Specs and sound are not the only criteria for judging microphones. The psychological effects of
weight, size and shape are important, too.
According to Crown Mic Dept. manager Tom Lininger, “Musicians buy microphones by the pound.”
That is, a heavy mic is more impressive than a lightweight one, regardless of specs. Light weight in a
microphone suggests that it’s a cheap plastic mic.
The size of a microphone also contributes to its perceived value. A big mic connotes big bass. That’s
why recording engineers prefer to mike the kick drum with a big microphone. In general, large cardioid mics do have deeper bass than small cardioid mics. Surprisingly, though, many mini omni condenser mics — like a GLM-100 — have a flat response down to 20 Hz. The GLM-100 works great in
a kick drum. But some people refuse to believe that a tiny mic can have any bass.
GLM-100
Vocalists seem to prefer side-addressed mics rather than end-addressed mics. A probe-shaped mic,
which picks up from its end, looks like an accusing finger pointing at the singer. Many singers are not
comfortable using such a mic. They prefer to sing into the side of a large microphone. This type of
mic looks like it’s listening to you. It’s all ears! The mic is “accepting” rather than “probing.”
Even David Letterman likes the look of a big, side-addressed mic on his desk — even though he’s
picked up by a lavalier.
Some vocalists like to “eat” the mic that they use on stage. In the studio, it’s hard to keep them away
from the recording mic. A common trick is to give the singer a dummy handheld mic to sing into. The
mic used for the actual recording is placed several inches away.
It’s easy to make people think that a mic is highly directional by putting a short shotgun tube on it.
Such a mic has a tight pickup pattern only at high frequencies. The tube must be a few feet long to
have a tight pattern down to low frequencies.
Before I knew much about mics, I thought that any mic with a ball-shaped grille must be omnidirectional. It’s the design of the mic capsule that counts, not the shape of the grille.
Here’s a more subtle psychological effect: Some people assume that any costly, name-brand mic
should sound accurate without any EQ. But many mics sound bassy when used up close. It’s the
proximity effect of directional mics. Mic placement affects the sound drastically too. You don’t just
place a mic near an instrument and settle for what you hear. You fix it with EQ or change the mic
placement until you like what you hear. The “sound” of a mic is the sound of its placement, too.
HOW TO COVER A LARGE CONFERENCE ROOM
A customer called Crown asking how to mike conferences for recording in a large library. The room is
30' wide by 50' long by 10' high. People are seated at tables in this room, and no mics are allowed on
tables.
We suggested that he install eight Crown PZM-10 mics in the ceiling, 10 feet apart and 10 feet from
the walls (Fig. 1). This array gives even coverage of the floor area. Feed the mics into an automatic
(gated) mixer so that only one mic is on at a time.
Fig. 1. PZM-10 ceiling miking.
GLM VIOLIN MIKING
You might want to try this miking position for a GLM-100 mini omni: Tape the cable to the tailpiece so
that the mic is between the tailpiece and bridge.
This spot on the violin radiates all the frequencies that the violin produces. It sounds wonderfully
natural.
CM-310a AS A GUITAR MIC
Sound engineer Randy Glanders reports that the CM-310a Differoid worked great on the acoustic
guitar in a bluegrass group. Randy put the mic about 8" from the sound hole.
Randy says, “It sounded natural and had plenty of gain before feedback.”
40 SWITCHABLE MICS INTO ONE INPUT
Design engineer Brad Holman wanted to switch 40 PCC-160 mics on and off, and feed them all into a
single mic input in a Bogen PA amplifier. Since only one mic preamp was used, the cost of the system
was very little. Holman describes the system:
“We have a convention hall with 40 PCC microphones mounted on 4' x 4' boards suspended from the
ceiling. They are spread throughout the hall, and 20 loudspeakers are interspersed among them. We
built a switch box that will enable only one microphone at a time, and turn off the speakers (controlled
by relays) that would create feedback to the active mic. My part was to design and manufacture the
computer circuit that controls it all.”
“We eliminated the pop of switching from one mic to another by having the CPU (Motorola 68HC11)
inhibit the input to the Bogen PA amplifier that our switch matrix is feeding.” In other words, the Bogen
mic input is muted before the mics are switched, so no switching pops are heard.
Here’s how the switching circuit works. Each mic feeds an inexpensive 1:2 step-up transformer,
which increases the signal level feeding the Bogen. A DC voltage (18V) is applied to the center tap of
each transformer to supply phantom power to each mic.
The secondaries of all the transformers are wired to a bus connected to the Bogen mic input (Fig. 2).
Normally, all but one relay switch is open, so only one mic feeds the Bogen. Although 40 mics are
across the bus, they don’t load each other down because their in-line relays are open. The computer
closes the relay switch for the active mic.
Fig. 2. Mic combining circuit.
Originally, Holman had a 10 kilohm software-controlled pot in series with each mic to control the mic’s
volume. But these pots added a lot of noise. He removed them. Also, each mic’s input transformer
was wired 2:1 instead of 1:2. Reversing the transformers boosted the signal level 12 dB.
According to Holman, “The system is operating great. We have virtually no noticeable noise, and
excellent S/N ratio.”
REDUCING BREATH AND CABLE NOISE IN THE CM-10
Suppose you are miking someone with a Crown CM-10 lavalier mic, and you hear breath pops —
even with the supplied windscreen. Try turning the mic upside down in its holder to reduce breath
pops. This orientation rolls off the highs slightly: 1 dB at 5 kHz and 1.5 dB at 10 kHz. If feedback is
not a problem, you can get the highs back by using EQ. Thanks to Mark Chapman, Crown tech
support, for this tip.
What if you hear cable noise whenever the person moves? Tie a fairly tight knot in the mic cable near
the mic. The knot’s mass will act as a filter to stop cable noise from reaching the mic. Another tip:
Tape the cable to clothing so the cable can’t slide.
RECORDING A BIG BAND WITH GLMs
The normal use for a Crown GLM-100 mini omni mic is clipped onto a musical instrument. But you
can use GLMs for distant miking if the sound source is loud enough to override the mic noise.
Such is the case when you mike a big-band jazz group. Try two or three spaced GLMs about 8 feet in
front of the ensemble.
If the band has a singer who uses a handheld mic, you might rubber-band a GLM-100 to the mic grille,
and record the GLM’s signal. Mix it with the distant GLMs.
NOVEL CHOIR MIKING FOR PA
John Coker of San Antonio, Texas devised some PZM corner boundaries for PA use in a theater (Fig.
3). He hung three of these boundaries upstage and three downstage, 8-1/2' to 10' high.
Fig. 3. Coker’s choir miking technique.
John says, “Compared to conventional cardioid mics, I get a better blend of the choir on stage.” He
also gets more gain than with cardioids, but he says that “You still need some good EQ.”
“The PZMs seem to have a slower fall-off in level with distance than cardioids do,” reports John.
SASS FEATURED IN SONGWRITER CD
The Crown SASS-P MKII stereo mic helped create a beautful, realistic sound on the compact disc,
“Love Keep Us Together.” The CD is a live concert of some very original singer/songwriters. It was
the the Third Annual Singer/Songwriters’ Retreat at the Wintertide Coffeehouse in Martha’s Vineyard.
Adam Blackburn, a recording engineer for Blackburn Digital, had this to say about the recording:
“The Crown SASS-P MKII was used primarily to provide accurate stereo imaging and three-dimensional depth to the recording, in addition to capturing audience reaction and the ambient house mix.
The SASS was attached to a standard short mic boom and hung from lighting pipes, about 7' above
and 5' into the house from stage center, above the front row of audience seating. Close mics accounted for about 60% of the stereo mix.”
One song was recorded with the SASS alone. “In my opinion,” said Blackburn, “this recording is one
of the best on the record because of its realism, both in terms of the precise reproduction of the sound
stage and re-creation of the heady, intimate, late-night atmosphere.”
If you’d like to hear this very entertaining CD, you can order it by phone at 508-693-8830.
SASS RECORDS EFFECTS FOR “CONGO,” “TRUE LIES”
Much of the impact of current motion pictures comes from the sound track. And a major part of the
sound track is the sound effects. In the recent movie, “Congo,” Wylie Statement of Sound Deluxe,
Hollywood, used the Crown SASS-P MKII stereo mic to record all the jungle sounds.
And in the Arnold Swarzenegger movie, “True Lies,” all the sound effects — gunfire, crashes, jets —
were done with the SASS.
Currently, the BBC employs the SASS to pick up tennis matches in stereo.
Thanks to SASS inventor Michael Billingsley for this information.
LETTERS FROM CROWN MICROPHONE USERS
I produce a live dance show on radio at a Chicago night club. We operate in an ambient SPL of 100
dB. Using a CM-310a on a wireless belt pack, the talent can wander the house — amid, beneath, and
in front of live speakers with limited feedback problems. Interviewing mic-shy artists and guests is a
snap.
D. Peter Maus, Maus Productions, Chicago, IN
###
MIC MEMO
Spring 1996
Bruce Bartlett, Editor
PZM ON CHEST MAKES GREAT DRUM DEMOS
Home recordists like to use drum machines because they produce a good sound without much effort.
And they don’t tie up a lot of tracks. Problem is, drum machines tend to sound stiff and mechanical,
so listeners are tiring of them. You don’t get the feel you have with acoustic drums.
Pro drummer Rick Shlosser has the perfect solution: Use a real drummer, and record the kit with a
PZM on the drummer’s chest (Fig. 1). Put another mic in the kick drum.
Fig. 1. PZM on chest.
“I was ecstatic when I tried it,” says Rick. “The PZM picks up everything: snare, toms, and cymbals.”
Rick has played with such luminaries as Rod Stewart, James Taylor, George Benson, Juice Newton,
Bonnie Raitt, Linda Ronstadt, Jackson Browne, and many more. He knows what he’s talking about
when he says “The PZM sounds great.”
“Many small studios can’t handle the expense and the acoustics of multimiking a drum set,” Rick says.
“A single PZM provides an easy, low-cost way to get a killer drum sound. Your drums sound best
where you’re sitting, so it makes sense to put the mic there. If you have a drummer with good dynamics, you don’t need an engineer to get a good balance.”
Rick is trying to get real drummers back in vogue in the studio. A PZM makes it technically easy to do
that.
Because of the limited size of the chest “boundary,” the low frequencies are a little weak. You might
want to boost the lows on your mixer’s EQ about +6 dB around 80 Hz.
Probably the best PZM choice for chest miking would be a PZM-6D. On the back of its plate, you
could gaffer-tape a shoelace which you hang around your neck. If it’s a permanent setup, you could
drill some holes in the plate and tie on the shoelace. Also tie a big loop of elastic onto the plate, and
stretch the loop around your chest.
Another mic that sounds super on a drum set is the GLM-100 mini omni mic. You can mount it with
the GLM-UM Universal Mount, which is supplied with the GLM. Clip the GLM-UM to the rim of the
snare drum, on the side nearest the center of the set. Put the GLM about 4" above the snare drum
(Fig. 2). Another mic goes in the kick. With a little bass and treble boost on the GLM, the sound can
be surprisingly good for demos.
Fig. 2. Miking a drum set with a GLM-100.
Here’s a stereo technique that uses two CM-700 cardioid mics. Place one mic about 1 foot to the left
of the drummer’s left ear. Place the other about 1 foot to the right of the right ear. Aim them at the
drum set (Fig. 3). The mics will pick up the set in stereo, very much as the drummer hears it. Boost
at little at 60 Hz and 4 kHz to compensate for the Fletcher-Munson effect. Mix these two mics with
another one in the kick.
Fig. 3. Miking a drum set with two CM-700’s.
WHITE WINDSCREEN FOR CHOIR MICS
Crown recently added a white windscreen for the CM-30W and CM-31W, model WS5W. It is packaged with the product at no additional cost. You can order it separately from your Crown dealer.
CROWN ONLINE
Be sure to check out the new Crown Web site on the Internet. It’s full of pictures and info on Crown
mics, amps, IQ systems, broadcast systems, and TEF. Point your web browser to http://
www.crownintl.com.
Crown is also offering Fax On Demand (Fast Fax system). It’s a database of information you can
have faxed to you. There are data sheets, price lists, articles on mic techniques, and much more.
To access Crown’s Fax On Demand, call 1-800-294-4094. Follow the voice prompts to get a document index, then order the documents you’re interested in. Enter your FAX number, and you’ll receive
the documents instantly.
Have an interesting application for Crown mics? You can send it by email to the Mic Memo editor,
Bruce Bartlett. My email address at Crown is bbartlett@crownintl.com. Hope to hear from you!
CEILING MIC PRECAUTIONS
When you mic a group of people from the ceiling, the sound pickup tends to be noisy and muddy.
That’s because the mics are relatively far from the people talking. As a result, the mics pick up a lot
of background noise and room reverberation. If possible, place the mics closer to the talkers, ideally
on a table. Also try to deaden the room acoustics with curtains, carpet, and acoustic tile ceiling.
Thanks to Mike Pettersen of Shure Brothers for this tip.
MIKING AUDIENCE REACTION
Cheers, claps, singing, laughs, applause — that’s what makes a recording sound “live.” So be sure to
pick up the audience reaction when you record a concert, game show or church service. Hearing the
audience greatly enhances the feeling of being there at the live event.
How do you mike an audience? Basically, you want the mics to pick up only the audience, not the
musicians or the PA. So you use directional mics, and aim their “dead” rear at the stage. A good
choice is condenser mics with a flat response and low noise.
To cover an audience, it seems reasonable to use PZMs on the ceiling. This is not recommended.
The mics will pick up too much noise from ceiling fans, air conditioning, and building vibration. Also,
do not put the mics on each side wall. If you do, the stereo spread will be ping-pong, and the mics will
pick up the PA speakers.
Probably the best spot for PZMs is on the front face of the stage — the surface that faces the audience (Fig. 4). Tape a pair of PZMs there about 3 feet apart. Since the mics are in the “sound
shadow” of the stage, they won’t pick up much sound from the musicians or monitor speakers. When
mounted on the stage front, the mics become directional with their axes aiming at the audience. Run
some mic cables from the mics into your stage box.
Fig. 4. Audience miking.
Another method uses a SASS stereo mic (or a pair of CM-700 cardioids) on a tall stand, or hung from
the ceiling. Place the mics in front of, above, and aiming back toward the faces of the audience (Fig.
4). Voice articulation is best with the mics in front of the people’s mouths. If you mic the audience
from overhead or behind them, you lose speech clarity. That’s because high frequencies radiate in
front of the mouth.
Don’t put the audience mics far from the stage, because their signal will be delayed by sound’s travel
time. When you mix in the audience mics, you will hear an echo.
How much delay will there be? Sound travels 1130 feet per second. So if the audience mics are 100
feet from the stage, they will pick up the PA with an 88 msec delay. (Delay = distance/1130). You
could delay the stage mix by 88 msec (or whatever) to coincide with the arrival time of sound at the
audience mics.
Spaced mics give a desirable spacious feeling to audience reaction because of the random phase
between channels. Another advantage of spaced mics: The mic stands are left and right of center,
which looks less distracting than a single stand in the middle.
To reduce pickup of air conditioning rumble and bass from the PA, roll off the lows below 100 Hz, or
use a 100 Hz highpass filter.
Of course, do not feed the audience mics through the PA speakers or you will get feedback. If the
audience mics are run into the PA mixer, be sure to un-assign them from the PA mixer main outputs.
Send their signals (by direct-out jacks) only to your recording mixer. Better yet, plug the audience
mics directly into your recording mixer.
What if you are recording multitrack, but you do not have enough tracks for the audience mics? Since
audience reaction is so important, you must find a way to record it. Here are a few suggestions:
*Send the audience mics to two tracks that are also used for instruments. For example, assign the
audience mics to a guitar track and keyboard track. While listening to a well-balanced stereo monitor
mix, bring up the audience-mic faders just a little, and only when you need them.
*Record the audience reaction on a separate DAT recorder. During mixdown, sync the DAT roughly
by ear with the multitrack. Mix in the DAT’s recorded applause only after each song.
*Another method uses a Digital Audio Workstation (DAW). One form of DAW is a computer with a
sound card, running a multitrack digital-audio editing program. Use a program that lets you move the
tracks in time relative to each other. Record the music mix onto two DAW tracks. Then record the
audience (from the DAT recording) onto two more DAW tracks, roughly in sync. Slide the audience
tracks in time so they sync exactly with the music tracks.
WIRING A CM-312/E FOR 2-WIRE POWER
The CM-312/E is a headworn mic that you use with a wireless mic transmitter. Normally the mic
requires B+, audio and ground inputs on the transmitter. But you can wire the CM-312/E to work with
transmitters that have only a hot and ground connection, such as the Sennheiser SK 2012.
Fig. 5. Wiring schematic.
Figure 5 shows how. Get a 9-volt battery, battery clip and 4.7 microfarad capacitor. Tape them to the
outside of the transmitter and wire the mic as shown.
NEW TRANSMITTER WIRING GUIDE
Do you want to connect a Crown mic to a wireless transmitter? Our latest Tech Bulletin #3 tells how.
It’s titled “Connections for Wireless Microphone Applications.”
To tell if you have the latest version, look at the bottom-right area of the cover. The date of the latest
version is 12/95. It has updated info on several wireless mic transmitters, including Micron.
A typo crept into this bulletin. The correct TA4F wiring for a Telex WT-55 is Pin 3 red, not Pin 4 red.
Also, you can connect the CM-312/E mic to the WT-55 without any modification to the transmitter.
SWEET CM-700 REVIEW
In “Sweet Notes,” a newsletter from pro audio dealer Sweetwater Sound, was a brief review of the
new Crown CM-700. It’s a cardioid condenser mic for stage or studio. Jim Miller had this to say:
“I just received a Crown CM-700 microphone for evaluation and frankly, after trying it out, I couldn’t
believe that this mic actually carries a list price of just $289! It’s a versatile performer that really
stands up to the high sound pressure levels produced when close-miking a drum, yet it’s still detailed
enough for miking acoustic instruments or even vocal work. If you need an extra quality mic in your
studio (and who doesn’t?), this might be the perfect choice.”
NEW LOW-COST SASS
For $625, Crown is offering the SASS-P MKII HC, which is a SASS-P MKII without the carrying case.
A windscreen is packed with the mic. The carrying case, hand grip and thread adapter are not included, but can be purchased separately as accessories.
The original SASS-P MKII (with all accessories included) is still available for $950 suggested retail.
LETTERS FROM CROWN MIC USERS
CM-311 tip
I’m a lead vocalist, keyboardist, and live sound engineer all at the same time. My CM-311 makes all
this possible — and sounds awesome too! To back off the mic’s volume during loud vocal passages, I
push the mic further away, down my chin, with my bottom lip!
Dean Bohana, Acme Music Co., Miller Place, NY
Hello from Ken Wahrenbrock
We received the following letter from Ken Wahrenbrock, who developed the first commercial PZM.
He also was the first editor of the PZM Memo, which now is the Mic Memo. Good to hear from you,
Ken!
We appreciate getting the Mic Memo, and note with interest the many ways mics are used.
The last issue [Winter 1996] brought back some old memories. I pulled out Vol. VI, No. 2, which
relates the development of the multiboundary PZM. It has several pictures.
I’m glad there are still some explorers out there in mic technology and use. PZMs can provide a lot of
sound.
Ken Wahrenbrock, Downey, CA 90242
###
MIC MEMO
Summer 1996
Bruce Bartlett, Editor
RAVE REVIEWS FOR THE CM-700
CM-700
After listening to some tapes made with the Crown CM-700 cardioid condenser mic, recording engineer Richard Shomin had these comments:
“The Crowns [CM-700’s] sound excellent. The 700’s produce a good drum percussive push on headphones, smooth and realistic. All instrument and voice sounds are clean and natural, no exaggerations, low distortion. Excellent fiddle, percussion edges, natural percussive sounds, good balanced
bass. Some of the cleanest sounds yet. Those CM-700’s are a good buy!”
Richard Shomin, recording engineer, Cornell, Michigan
“A fine, fine mic for the price. Heck, twice the price!... I’m recommending that my recording school
buy four to six CM-700’s because they’re the best mic for the buck right now.”
Christopher Goosman, House Engineer at Solid Sound, Ann Arbor, Michigan
Instructor in Audio Recording Technology at Washtenaw Community College
“I’ve heard several singers and two sax players on the CM-700. The saxes sounded really natural,
like you didn’t have a mic in front of ‘em! There were regulars in the audience asking about the mic.”
Ward Kremer, Recording Engineer, Fort Lauderdale, Florida
“Here’s a new contender many engineers may find hard to pass up... The CM-700 is a robust little
unit, built with the ruggedness for which Crown is famous...
“We used the CM-700 on the hi-hat. The microphone proved perfectly suited for the task. Its relatively small size made it easy to position, and left plenty of clearance for the cymbal directly above the
hats. With the bass-tilt switch set at maximum rolloff, the mic delivered a bright, crisp sound. We are
confident that the CM-700 would perform equally well as an overhead drum mic.
“On the cello, the sound was warm and full yet brilliant at the top... We were really pleased with the
response and dynamic range of the CM-700 in this setting, and we wouldn’t hesitate to use it on any
number of acoustic stringed instruments including guitar and mandolin...
“[In stereo miking a group of Japanese taiko drummers], the CM-700 performed beautifully... Thanks
to the excellent rejection characteristics of the CM-700’s cardioid pattern, we had enough gain before
feedback to pump it up in the room. The CM-700 would definitely perform well as a choir mic...
“The CM-700 is a superb, extremely versatile mic, sensitive enough for capturing acoustic performances, yet rugged enough to handle the SPLs delivered by a drum kit or powerful vocalist. It is an
extremely flat and quiet microphone with very low off-axis coloration...
“The CM-700 would be a wise choice — especially when you consider that many of its competitors will
cost you twice the money, if not more.”
Lori Bolender and Mike Cutter, Electronic Musician
CM-10 MIKING ADVICE
Fig. 1. CM-10 in use.
We’ve gathered some tips about using the Crown CM-10 lavalier mic in stage, film and video applications.
*To reduce clothing noise, spray the fabric with Static-Guard before putting on the mic.
*Using a vinyl-covered paper clip, build a small cage around the mic so that fabric doesn’t rub on the
mic.
*Ask the wardrobe department whether they can tailor an actor’s costume to hide the mic. To avoid a
muffled sound, use clothing made of cotton or fine-weave wool.
*Tape the mic to the chest using Microporous adhesive tape.
*Disguise the mic in a pen cover and put it in the shirt pocket.
*Using bobby pins, put the mic in the hair, poking out under a wig, or just above and behind the ear.
*Hide the mic in the collar.
USER REPORTS ON THE CM-311 HEADWORN MIC
Fig. 2. CM-311
Here are some unsolicited comments from the Internet on our CM-311 headworn mic:
“Take the time to adjust the headband so that the mic capsule is VERY close to the lips. Great rejection of outside sounds. I’ve used it with some very loud drummers and it works like a charm.”
Lee Brenkman, Brenkman Audio Services
“Try the Crown headset mic (the Garth Brooks mic). They sound crystal clear, and a lot better than a
58! Also, they do not become snare/hi hat mics like the AT, or sound like a can like the AKG or
Shures.”
Mike Cohn, Guerilla Audio
HOW SHOULD I MIKE THIS CHOIR?
We received the following letter from Nelson Cox, a sound engineer for his church:
“We want to install mics for the choir, primarily for recording the service. The choir consists of 35 to
40 people in three rows, grouped mainly on the right because of the protrusion of the baptistry on the
left. Pipe organ and loudspeaker system are behind the screen, above the heads of the choir. RFI is
a consideration.
“The ceiling is too high to hang the mics. I’d prefer to string a horizontal wire over the choir and hang
the mics from that.
“Considering the shape of the choir loft and the placement of the loudspeaker system and organ in
relation to the choir, what is the best way to mic the choir?”
Our reply:
Try the Crown CM-31 hanging mics. To prevent picking up the loudspeaker system with the choir
mics, I suggest that you mike only the right half of the choir. That way, you can aim the mics away
from the loudspeaker. Angle each choir mic to the right slightly so that the loudspeaker is 125 degrees off-axis to each mic (see Fig. 3). That’s the null, or the angle of most rejection, of each
supercardioid mic.
Fig. 3. Choir miking.
Use two mics. Position them so they divide the right half of the choir in thirds. You’ll need two horizontal wires, one for each mic.
Hang the mics about 3 feet above the head height of the back row of singers, and 3 feet in front of the
front row of singers. This is closer than mics are normally placed for recording, but you’re trying to
reject the loudspeakers. You may want to add artificial reverb to the choir mics. Excellent digital
reverbs are available for under $200.
You might want to put a dummy mic on the left half of the choir so they don’t feel left out. :) Or put a
Crown CM-200A cardioid mic on a mic stand near the left half for solos. The soloist should stand
about 1 foot from the mic. Good luck!
USER TIPS ON PZM-30D, GLM-100
PZM-30D
On the Internet, Bob Berta had this to say about the Crown PZM-30D Pressure Zone mics:
“These are incredible mics that are excellent for [recording sound effects]. I use them for recording
pipe organ, orchestras, bands, quartets, and solo musicians. They don’t mount on a mic stand...
instead they sit on the floor, taped to a wall, or to a 2’x 2' square sheet of plexiglass...
“I simply put the two PZM mics on the floor at the front of the stage (in a school auditorium) about 2'
apart. The imaging and sound are amazing. Plus you don’t have the mics bothering the performers.
You can’t get a bad recording with them, it seems.
“You can mount the mics to walls, floors, balcony, etc. They are designed for [distant] miking. For
pipe organ, orchestra, etc., they are the way to go. You eliminate much of the ‘in a drum’ sound that
you get with any other mics when distant miking.
“You can also take sheets of plexi and mount them in several configurations with two mics to create
wonderful stereo pickups or focus their pickup areas. For wild stereo just mount two on opposite
sides of the plexi and place it in the middle of a group... then listen with headphones.
“When you use two sheets and stand them up in a V pattern with a 100-degree spread at the back,
you provide a somewhat cardioid pattern but with much better imaging than you get with the traditional
2-mic approaches of coincident pairs, etc.
“[The PZMs are] very quiet, 20-20K frequency response, very low noise floor, omnidirectional. They
have a switch that allows you to go from dead flat frequency response (really flat) to a slightly rising
top end for percussive sounds like drums, piano, guitar, etc.
“These mics are phenomenal! The 30D mics are the most adaptable to a wide variety of uses. If you
get them be sure to get the free application booklets from Crown.
“The GLM-100 is a tie-tac size mic that you mount directly onto musical instruments. It is fabulous for
direct miking of instruments like flute, strings, horns, accordion, etc. Very inconspicuous. It is omnidirectional, 20-20K aand very low noise floor.
“Both of the Crown mics are equal to ANY studio condensers I have used in sound... very detailed, no
bad spots or muddiness. To me they sound much better than a lot of highly rated mics.”
Bob Berta, rkb4@pge.com
CM-700s SHINE ON FOLK RECORDING SESSION
Last April, I recorded a cassette album of folk music featuring Mark and Liza Woolever. We used
Crown CM-700 cardioid condensers on all the instruments. The miking went like this:
Fiddle: 1 to 2 feet over the top, aiming at the bridge.
Bodhran (Irish drum) or tambourine: 1 foot from the center.
Lap dulcimer: 1 foot over the middle of the top.
Acoustic guitar: 10 inches from where the fingerboard joins the body, aiming at the sound hole.
Tin whistle and recorder: 8 inches from the middle of the instrument.
Vocals: Crown CM-200A 1 inch from the mouth, with a foam windscreen, EQ’d -6 dB at 100 Hz.
Mark and Liza said that they were really pleased with the clear, natural sound of their instruments.
CORRIDOR CONCERTS BRING LIVE MUSIC TO RADIO
Putting live music on the air is a thrill. At our local public station, WVPE-FM, we produce “Corridor
Concerts.” A band comes in and sets up in the corridor or hallway outside the control room. There, I
mike and mix them as they play. The mix is sent live over the air.
This was the miking setup for a recent concert of a folk duo named Merriweather:
*Acoustic guitar, mandolin, bouzouki: CM-700 cardioid condenser, a few inches from where the
fretboard joins the body, with the bass-tilt switch set to rolloff.
*Hammered dulcimer: CM-700 about 6 inches out from the front edge, 8 inches up.
*Vocals and flute: CM-200A with a foam windscreen, lips touching the windscreen. The mic is angled
up to reject the guitar and monitors.
Here are some tips on mixing live. Before the show, write a numbered list of your mixer inputs. Next
to each input number, note the instrument or vocal for that input, and the mic you plan to use on each
one. Put the list by your snake box and plug in mics accordingly.
You’ll need to mike close to avoid phasing between mics and to reject room acoustics. Close miking
can color the sound, so be prepared to use a fair amount of EQ. Most mics will need some bass
rolloff to compensate for their proximity effect (up close bass boost).
Fade down mics not in use by about 10 dB. This gives a cleaner sound and reduces phase interference between mics. Do not turn the unused mics all the way off, or you may miss cues.
Technicalities aside, mixing music live to air is on-the-edge radio — fun for both the performers and
the listeners.
LETTERS FROM CROWN MIC USERS
Live radio
I produced the St. Jude’s Radiothon at Randhurst Mall. It could have been a feedback nightmare,
because I used off-air monitoring of the radio station, with heavy processing and 40 dB of compression.
I used three Crown CM-310A’s on the dais between the PA/monitor speakers, and a SASS-P for mall
ambience. It came off like a breeze. A long breeze, to be sure, but a clean one.
D. Peter Maus, Maus Productions, Chicago, Illinois
###
MIC MEMO
Fall 1996
Bruce Bartlett, Editor
SIMPLIFY YOUR MIKING WITH PCCs
Want to keep your miking clean and simple? Often, a single PCC-160, PCC-170 or PCC-130 can
replace several other mics, and do a better job.
For example, consider miking a group of panelists on a TV talk show. The usual approach is to clip a
lavalier mic on each person, and either ride gain or use an automatic mixer. A simpler method uses a
single PCC-170. Seat the people on adjacent sides of a square table. Put the PCC on the opposite
corner of the table, aiming at the people (Fig. 1).
Fig. 1. TV panel miking.
With this technique, there is no phase interference between mics. And surprisingly, the panelists will
sound like they are close miked.
Here’s an easy way to mike a choir for sound reinforcement. In front of each 12-foot width of singers,
put a PCC-170 on the floor, 8 feet away. You can expect very good gain and an excellent vocal blend.
Plus, you eliminate the visual clutter of mic stands.
If you prefer to use a PCC-160 for its extra ruggedness, it may sound too bright. If so, turn down your
mixer’s EQ a few dB at 10 kHz.
On a theater stage that is 30 feet wide or less, a single PCC-160 often can cover the area as well as
three or four PCCs. Put just one PCC a foot or two from the stage edge, in the middle.
If you use several mics instead, you have to ride gain on each mic to follow the action on stage. Not
so with the single PCC — just set it and forget it. Also, one mic has more gain before feedback than
three mics.
Sometimes you may need to use wireless lavalier mics or spot mics on the set. But often a single
PCC can cover most of the stage area quite well.
OVERHEAD PZM SPACING
Suppose you’re recording a conference with PZMs on the ceiling. How far apart should the mics be to
get uniform coverage?
Use the two-times rule. The spacing between mics should be two times the distance from mouth to
ceiling. For example, if the ceiling is 5 feet above the talkers’ mouths, the mics should be 10 feet
apart. Then the mics will pick up everyone about equally.
In general, use as few mics as possible that will do the job.
If several mics are on at the same time, the recorded sound will be reverberant or muddy. It helps to
run all the mics into a gated mixer (automatic mixer), which turns off all mics except the one in use.
This keeps the sound clear.
Note that PZMs on the ceiling are NOT a good choice for P.A. The mics are too far from the talkers to
get enough gain before feedback.
DRUM MIKING TIPS
The following techniques on miking drums are from Mark Frink, sound reinforcement editor for Mix
magazine. Mark suggested some novel ideas in the June 1996 issue:
“The most overlooked condensers for miking drums are the smallest. One of my favorites is the
Crown GLM-200. Last year, for Tony Bennett’s ‘Unplugged,’ I used a pair of these on Clayton
Cameron’s 4-piece Ludwig jazz kit — one each just below the hi-hat and the ride cymbals. Using a
short piece of coathanger, these were duct-taped to the cymbal stands using a small piece of foam as
a shock mount, so that they were facing each other over the snare drum from each side of the kit.”
Mark used other mini mics on the snare and kick.
“Panning the [GLM-200] cymbal ‘underhead’ mics, a wide drum sound is achieved, with the snare and
kick mics adding to make it big and fat. This four-mic technique compares favorably to individually
miking kits where dynamics and skill, rather than volume, become the focus. The microphones can’t
be seen. I’ve had people come up and ask where the mics are, or why the acoustics are so good in
the hall.”
“Engineers can take advantage of drum sets that are isolated with Plexiglas and use these large, flat
surfaces to mount Crown PZM mics to take advantage of boundary effects. Two PZMs, placed correctly and panned, will often eliminate the need for other mics.”
CM-30 PROVIDES CLEAR SOUND IN HEART-CATH LAB
Tony Hackett, general manager of Thompson Communications in Nashville, told us how he uses
Crown CM-30 hanging mics in a medical application. In the Vanderbilt University Medical Center are
several heart catherization labs. Each lab includes a procedure room, where the doctor inserts a
catheter into a patient, and a control room, where an operator controls equipment.
CM-30
A CM-30 supercardioid mic picks up the doctor from anywhere in the room. The CM-30 is hung about
1 foot below the ceiling, which is 10 feet high. According to Tony, “It sounds great. The clarity is
unbelievable.”
In the control room, a loudspeaker or a headset plays the doctor’s voice to the control-room operator.
The operator talks to the doctor over a headworn mic.
Tony has installed ten such systems for a cost under $1200 each.
CHOIR MIC SPACING
Many Crown mic users ask: How far apart should I put my choir mics to pick up everyone equally?
If the choir is 9 feet wide, use one mic 3 feet from the front row.
Choir 20 feet wide: Use two mics 2 feet away, 10 feet apart.
Choir 40 feet wide: Use two mics 2 feet away, 20 feet apart.
Choir 60 feet wide: Use two mics 3 feet away, 30 feet apart.
How did we get those figures? We will call the pickup “uniform” if each singer is picked up at a level
within 3 dB of each other. A supercardioid mic (like the CM-30) is down 3 dB at 58 degrees off axis.
This corresponds to 4.5 feet off axis if the mic is 3 feet away from the choir. Hence, one mic 3 feet
away can pick up a choir 9 feet wide.
What if you use two mics? When both mics pick up a singer midway between them, their signals add,
so the level goes up 3 to 6 dB. So the singer can be at the 6 dB down point of the supercardioid
pattern. That happens at 78 degrees off axis. This corresponds to 10 feet off axis if the mic is 2 feet
away from the choir. Hence, two mics 2 feet away can pick up a choir 40 feet wide.
GLMS AMPLIFY CONTRA DANCE BAND
Each month in Elkhart, Indiana, a contra dance group has a dance with music provided by acoustic
musicians. Contra dancing is like square dancing except that it’s done in two long rows and is more
energetic. The band plays Irish reels and jigs, and old-time fiddle tunes.
We wanted an inconspicuous way to mike the band with a natural sound. Our current system uses
several GLM-100 mini omni mics, one per instrument. These mics are run into a mixer, power amp,
and two bookshelf speakers from a home stereo.
The speakers are on chairs against the wall behind the musicians. Although you might suspect feed-
back would be a problem, it’s not. The reason is that the GLMs are attached to each instrument, so
not much gain is needed. Also, the performers’ bodies block sound from the speakers behind them
(Fig. 2).
Fig. 2. Contra dance band miking.
Here is a typical miking setup:
*Acoustic guitar: GLM taped to the body of the guitar, halfway between the sound hole and the bridge,
near the low E string.
*Banjo: Taped onto the drumhead a few inches in from the rim.
*Mandolin: Taped to the body near an f-hole.
*Fiddle: Positioned over an f-hole using the GLM-UM Universal Mount.
*Hammered dulcimer: Taped to the front edge, several inches over the top.
*Electric bass: Direct.
No mics are visible from the dance floor. The sound is just like the live band, only louder. There’s no
sense of technology getting between the musicians and dancers.
When the fiddle player needs to announce the name of the tune, she talks into her fiddle microphone.
The dance caller wears a CM-312 headworn mic, which is plugged into a wireless transmitter. She
prefers a headworn mic because she often calls while demonstrating dances, and needs both hands
free.
PRAISE FOR PZMs ON THE NET
The following question and answer were posted in the Internet newsgroup rec.audio.pro:
Q: “I’m currently looking to buy a pair of matched mics to do some live recording to DAT. I will be
recording everything from [pop group] Phish in an ampitheater to unknown folk bands in small clubs.
Any recommendation on mics that would fit the bill? I’m hoping to keep it around $1500 for the pair.”
A: “I would buy a set of the best Crown PZM microphones. They have a very smooth response, when
properly used, compared to stand mics. Crown has application notes on how to use them with
plexiglass shields for miking by hanging from the ceiling, or use as is by miking on the floor.
They are extremely versatile, and have a very smooth sound, whereas even the best stand mic will
suffer from comb filter effects due to the pickup of direct and reflected sound, which produces variations in the frequency response. The PZM approach does not suffer from these problems. And they
will be WELL under your budget” [$738/pair].”
Gary L. Sanders, V.P. Engineering, Sanders Media Adventures, Inc.
MIKING FOR DISTANCE LEARNING
In a typical distance learning system (Fig. 3), there are students in one or more classrooms, and a
professor in another location. The professor talks to the students through a clip-on or lavalier microphone. The mic signal is sent by phone lines or satellite to the classrooms. There, a loudspeaker
plays the professor’s voice to the students. The students can see the professor over a TV monitor,
and vice versa.
Fig. 3. Distance learning system.
In the classroom, each student or pair of students has a desk mic (Fig. 4). Students can switch on the
mic when they want to ask the teacher a question. The mic signals are sent by phone lines or satellite
to the teacher. The teacher and student can talk back and forth, almost as if they were in the same
room.
Fig. 4. Distance learning system.
A typical Crown mic in this application is the PCC-170SW desk mic. If you want remote sensing of
switch closure, substitute PCC-170SWO mics. These mics can be used with a video camera
switcher. When a person turns on his or her mic, the camera aiming at that person is switched on.
Then the TV monitor view tracks whoever is speaking.
One designer of a distance learning system is Greg Gogins, Technical Facilities Manager at the U. of
Minnesota. He asked us how to mike a student seating area (auditorium) which had ceiling mounted
speakers and noisy air conditioning.
Our reply:
We recommend that the mics be close to the students. Use push-to-talk mics on the backs of the
rows of chairs, one mic for every two students.
Crown makes a model PCC-170SW microphone for this purpose. It’s a surface mounted (boundarytype) mic with a built-in membrane switch to turn the mic on or off. The switch can be configured for
momentary on, momentary off, or push-on/push-off.
Normally this mic is placed on a desktop. Are there any desks or writing surfaces in the auditorium?
You might make a shelf held up with L-brackets that go on the back of the seats. Mount each mic on
top of this horizontal shelf.
An alternative is to use conventional mics on some sort of mic stands, and run all the mics into an
automatic (gated) mixer such as made by Shure Brothers. The gated mixer turns on only the mic in
use. You might use a lectern (gooseneck) mic, such as the Crown LM-300a, held to the seat back by
a metal strap having an omega cross section. That would be a clean installation.
LETTERS FROM CROWN MIC USERS
SASS: the mic of choice
I use the SASS series exclusively as my overhead mic when recording drum tracks in the studio. It
creates the best sound possible from the complete kit. The stereo separation is unbeatable. I have
also used it to record choirs in large churches, and high school bands. Everyone should own at least
two. It is the mic of choice for Digital Glue Studio.
Rick Owens
Digital Glue Studio
Midland, TX
CM-311 isolates drummer’s vocal
I’ve been using a [Brand X] microphone, but as a drummer/lead vocalist the mike was so “hot” that a
lot of additional sound came through the lead vocal channel. Your mike [CM-311] is “hot” enough for
vocals but not so much as to pick up interference. I used a headset mike a few years back, but it
couldn’t compare to the quality of this one. Nice job!
Jerry Murphy
Yukon, OK
###
Mic Memo
Winter 1997
Bruce Bartlett, Editor
AWARD-WINNING STUDIO USES CROWN MICS
Harrison Digital Audio Recording in Gurdy, Massachusetts, is National Public Radio’s producer for
southern New England. A few years ago, they won NPR’s award for best recording of the year.
Owner Jeff Harrison had this to say about the Crown mics he uses:
“We’re using the CM-700 condenser cardioid. That’s a pretty amazing little piece of equipment. We
just used it as a tuba microphone on a recent release and it acquitted itself quite well. It sounded
very, very nice.
“People ask us to record live shows. I’m finding GLM-100s useful for stage productions where we
hide them here and there on the set.
GLM-100
“The GLM-100s are very handy little devils. They fill the bill anytime we have to mike something in
which a microphone cannot be seen. They have a nice flat response and they sound good, and they
handle a high sound pressure level.
“We use them anytime we’re doing video work or a live stage show. They’ll go on the side of something in a drum kit, or on a floor underneath percussion, or inside the lids of pianos — which is the
most common use, probably.
“There will be more 700s joining our flock, and probably a few more GLM-100s. Develop some more
serious recording microphones and we’ll buy them!”
NEW APPLICATION GUIDES
How do you mike a teleconference? What’s a good way to mike a grand piano? The answers are in
two new Crown mic application guides:
1. CM, LM, and GLM Series. 2. Teleconferencing and Distance Learning
Mic application guide
Other mic application guides in this series are:
Speech Sound Reinforcement
Boundary Microphones
Houses of Worship
Schools
Studio
Security and Surveillance
All these booklets are available free from your Crown dealer, or directly from Crown. Just call the
literature room, phone 219-294-8093.
CROWN TEF-05 OMNI MEASUREMENT MIC
TEF-05
The new Crown TEF-05 [Now the CM-150] is a 1/2" diameter, omnidirectional electret condenser
microphone. It is intended for free-field TEF measurements, sound-level meter measurements, and
pro’ recording.
The TEF-05 has a very flat, wide-range frequency response (20 Hz to 20 kHz +/- 1.5 dB). The mic is
supplied with a proof-of-performance sheet, which shows frequency response and sensitivity. This
information can be used to calibrate the microphone. The mic capsule grille fits into a Bruel & Kjaer
4220 pistonphone.
Because of its pre-aged titanium diaphragm, the TEF-05 is extremely stable over a wide range of
environmental conditions.
When used for recording, the TEF-05 sounds natural and accurate. It preserves the delicate timbre of
acoustic instruments, yet can reproduce all the power of a pipe organ. The off-axis response is
smooth, so any leakage picked up has little coloration.
In close-miking applications, the mic’s self-noise is inaudible. The TEF-05 can handle very loud
sounds (127 dB SPL) without distortion. It is protected against static and RFI. The output is balanced, low impedance, which allows long cable runs without hum pickup or high-frequency loss.
Powering is by 18-48V phantom power.
An included foam windscreen reduces wind noise outdoors.
INTERNET COMMENTS ON THE CM-311
The following Internet message was posted in the newsgroup, rec.audio.pro:
Subject: What is a good headset mic for a drummer?
“I would like to ditto the Crown CM-311. I currently am using one with the Carman RIOT world tour,
which is in the round. This mic is fantastic. Has excellent rejection, and sounds great! The 311/E is
the best option, the electronics are built into the cord end.”
Ed Crippen
ecrippen@sprynet.com
CROWN MIC DEMO CD
CD cover
Want to hear what Crown mics sound like? Order the new Crown Microphone Demo CD. Every cut
on this CD is a sonic spectacular. Each selection demonstrates the sound of Crown microphones,
using a wide variety of music and sound effects.
Mics featured on the compact disc are the GLM-100, CM-200A, CM-700, SASS-P, SASS-P MKII,
PZM-30D, and PCC-160.
Partial contents include:
Sound effects: airplanes, gun shots, earthmovers, stereo imaging, and more.
Classical: Pipe organ, choir, orchestra, solo piano.
Jazz: Dixieland, percussion, quartets, ensembles.
Folk: Folk duos, folk groups, Baltic folk group.
Pop: Rock ‘n’ roll, pop, oldies, barbershop.
The CD is available free from Crown, but we must ask $4.95 for shipping and handling. Send your
order to Crown International, 1718 W. Mishawaka Rd., Elkhart, IN 46517.
THE 3-TO-1 RULE
Suppose you’re recording a singer/guitarist. There’s a mic on the singer and a mic on the acoustic
guitar.
The voice sounds funny — sort of filtered. What’s happening? The vocal mic is picking up the vocal
up close. The guitar mic is picking up the vocal at a distance. So there are two vocal signals in the
mix. One is direct and one is delayed.
When you combine a signal with its delayed replica at equal levels, certain frequencies cancel out,
depending on the delay. There appears a row of notches in the frequency response where the
sounds cancel. This is called a comb filter effect, because the frequency response looks like the teeth
of an inverted comb.
In general, if two mics pick up the same sound source at different distances, and their signals are fed
to the same channel, this might cause phase cancellations. These are peaks and dips in the frequency response caused by some frequencies combining out of phase. The result is a colored, filtered tone quality. It sounds like mild flanging.
To reduce phase cancellations between two mics, follow the 3 to 1 rule: The distance between mics
should be at least three times the mic-to-source distance. For example, if two mics are each 1 foot
from their sound sources, the mics should be at least 3 feet apart to prevent phase cancellations (Fig.
1).
Fig. 1. 3:1 rule.
How was the 3:1 rule determined? Mic engineers Lou Burroughs and Tom Lininger discovered the
following fact:
When you add a signal to its delayed replica at equal levels, you get severe comb filtering with deep
notches. But when you mix direct and delayed signals at different levels, you get less deep notches.
Specifically, if the delayed signal is 9 dB less than the direct signal, the comb-filter notches are only +/1 dB, so for all practical purposes they are inaudible.
How do we make sure that the delayed signal, picked up by a distant mic, is at least 9 dB below the
direct signal picked up by the close mic? Put the distant mic at least three times farther from the
source than the close mic is. Due to the inverse square law, the level drops about 9.5 dB when the
distance to the source is increased three times.
So the 3:1 rule ensures that the level at the distant mic will be down at least 9 dB, so the mixed signals will have comb filtering of +/- 1 dB or less.
A ratio of 4:1 or more is even better. The 3:1 ratio is the minimum to avoid audible comb-filter effects.
Suppose the close mic is picking up a loud piano, and the distant mic is picking up a quiet acoustic
guitar. You’ve placed the mics following the 3:1 rule. But you have to turn up the guitar-mic gain a lot
because the guitar is so quiet. If so, you might negate the 9 dB separation. That is, the piano signal
in the guitar track might be less than 9 dB below the piano signal in the piano track, because the
guitar-mic’s gain is so high.
So there’s more to it than just the 3:1 placement. The idea is to get at least 9 dB difference between
track levels for the same instrument. You want at least 9 dB of separation between tracks.
Here are some ways to increase separation:
*Mike close.
*Spread instruments farther apart.
*Put a gobo between them.
*Use directional mics, and aim the null of each mic’s polar pattern at the other mic.
*Record in a deader room. This reduces reflections into the front of each mic, which can degrade
separation.
*Use a pickup on the guitar instead of a mic.
If the close and distant mics are two cardioids aiming in opposite directions, the mics can be closer
than 3:1 and still get enough separation.
Also, don’t use two mics when one will do the job. For example, use just one mic on a lectern. If you
must use two mics mixed to the same channel, place them so their grilles touch, one over the other.
This will prevent phase cancellations by aligning the mic signals in time.
LETTERS FROM CROWN MIC USERS
PZMs and distant miking
From what I have heard, when you close-mike and distant-mike an instrument, and mix the mic signals, the distant mic should be two feet higher than the close mic.
Would it be true to say that, unlike other mikes, it doesn’t matter how high or low you place PZMs
when using them as a distant mike since they’re not prone to comb filtering? If this is true, is there still
any particular reason to keep them above or below the height of the close mike?
Geoff Goacher
Sound Advice Acoustical Consultants
Irvine, California
Reply: Like any other mic, A PZM is prone to comb filtering except from the surface it is mounted on.
A PZM mic capsule does not get comb filtering from its boundary plate, because the mic capsule is
very close to the plate. But a PZM raised off the floor will get comb filtering from delayed reflections
off the floor. This can be reduced if you raise the mic farther from the floor. Two feet higher is okay,
but is not a standard.
3-D guitar sound
Buy a GLM series miniature condenser and clip it inside of an acoustic guitar. Then blend it with piezo
electronics in the bridge, and then blend it with a cardioid dynamic that is pointed at the sound hole.
Then use a PZM to mike the room. The result is 3-D sound.
Stephen Guild
Portland, CT
Mic technique vs. EQ
I use mics for every step of the recording process. I feel that the science and physics involved in mic
placement no longer exists. Just put a $3000 condenser mic in front of the instrument and then tweak
the EQ till it’s correct. Hah!
Stephen Guild
Portand, CT
Improvised reverb chamber
I had a commercial project that called for reverb. My studio reverb unit was on the bench for repairs.
I found a 12-foot heavy cardboard tube, about 8 inches diameter. I drilled a small hole in the side near
one end. Into that end I inserted a GLM-100 and capped off the end with a coffee can.
The other end I capped with a coffee can whose bottom was punched with a 1" hole, 2" off center.
I held the punched end of the tube near my studio mic when I spoke. I sent the far-end GLM to a
separate track. I performed the read, and closed the account. It sounded funky, but it worked. The
account loved it.
D. Peter Maus, Maus Productions, Chicago, Il
Recording sounds at Great America
I recently produced two days of live radio at Six Flag’s Great America in Gurneee, Illinois. Miking an
amusement park is a snap with a couple of SASS-P’s [stereo mics] with wireless transmitters. Miking
the area around the broadcast setup was not difficult at all with a pair of GLM-100s [mini omni’s] taped
to fence posts between which most of the crowd would be standing. And of course, the talents were
on CM-310A’s [handheld differential mics].
The trick was the pair of helpers who rode the rides together, wired with GLM-100 lavaliers driving
wireless transmitters. The screams from the BATMAN ride and THE DEMON ride were breathtaking
and in stereo. Next time, though, I think I’ll invest in a profanity delay... Know what I mean?
D. Peter Maus
Maus Productions
Chicago, IL
###
MIC MEMO
Spring 1997
Bruce Bartlett, Editor
MIKING AN ORCHESTRA WITH GLM-200s
GLM-200
What’s a good way to amplify an orchestra? One method is to use a Crown GLM-200 mini
hypercardioid mic on each instrument. That technique works well for Randy Piotroski, a freelance live
sound mixer.
Randy says, “We’ve used the GLMs on several symphony orchestras: Pittsburg with Marvin Hamlisch
directing, San Diego with Nick Perito directing, Denver, North Carolina, Arizona, and Puerto Rico.
“Basically I close mike all the strings and blend them together. On each instrument, I clip a GLM-200
onto the strings just behind the bridge, aiming down at the body. That way the mic is not touching the
wood of the instrument. I use the tie clip with some heatshrink over the alligator clip.
“We like these Crowns for close miking. They take a lot without overloading.
“I’m using no compression, minimal EQ. I cut a little around 400 Hz and 8 kHz because the mic is so
near the body, it tends to sound a little woody.
“Typically our orchestra is 12 first strings, 12 second strings, 6 violas and cellos. On cello we drop the
mic down into the f-hole, free hanging about 4 inches in. We mute the cello mics when the song is
over to avoid klunks from player movement. As for EQ, we just highpass filter the mic until it sounds
fairly smooth. We didn’t have enough mics to try on the basses.
“We’re putting GLMs to darn good use. As long as I have the same microphones day in and day out,
it doesn’t matter what the PA is. If I have the same starting base, I can make it work.
“The GLM records well, too, without a lot of processing. I add a touch of reverb just to breathe air
back into the sound. I also use an ambient mic over each section: an AKG 414 in a figure-eight pattern.
“Initially, the musicians were reluctant for me to clip a mic onto their instruments. They would say
‘What are you doing? I’ve got an $8000 Stradivarius.’ But one by one they realized, ‘Hey, I’m not
being heard if I don’t use this mic.’ They all of a sudden wanted to put their mic on.”
TURNING ON MICS WITHOUT POPS
Sound Tech’s John Sprinkle designed a church sound system with several mics. When the minister
turns off his wireless mic, a relay activates phantom power for the choir mics to turn them on automatically. Unfortunately, this makes a loud pop over the PA speakers.
John said, “We have no mixer operator to ride gain. How can the choir mics be turned on without
pops?”
Our suggestion was this: Route the minister’s mic to group 1 in the mixer, and route the other mics to
group 2. Short the output of group 2 with the relay. When the relay kicks open, you will hear the
group 2 choir mics.
RAVES FOR TEF-05
TEF-05
Compliments are coming in for the new TEF-05 [now the CM-150] omni condenser mic. Although the
mic was designed for acoustic measurements with the TEF-20 sound analyzer, it also is great for pro
recording.
Bill Tullis, a sound engineer with Turner Broadcasting, compared the TEF-05 to similar models by
B&K and Earthworks. He had this to report about the TEF-05:
“We found the Crown TEF-05 microphone to be equal to the competition and superior where price is
concerned. The model is especially good for choir recording and sound effects gathering in controlled
locations, as well as ambience and crowd reaction. The flat response is great for recording high
strings and reed instruments, especially in classical applications.”
TIPS FOR RECORDING ACOUSTIC GUITAR
Fig. 1. Some mic techniques for acoustic guitar.
Reviewers have praised the Crown CM-700 cardioid condenser as being especially good for acoustic
guitar. Here are some suggestions for mic techniques.
To record a classical guitar solo in a recital hall, mike about 3 to 6 feet away to pick up room reverb.
Try a stereo pair (Fig. 1-A), such as XY, ORTF, MS, spaced pair, or a Crown SASS-P MKII stereo mic.
When you record pop, folk or rock music, try a CM-700 about 1 foot from where the fingerboard joins
the guitar body — at about the 12th fret (Fig. 1-B). That’s a good starting point for capturing the
acoustic guitar accurately. Still, you need to experiment and use your ears. Close to the bridge, the
sound is woody and mellow.
Another spot to try: Tape a GLM-100 mini omni mic onto the body, halfway between the sound hole
and bridge, about 1/2 inch from the low E string (Fig. 1-C).
The guitar will sound more real if you record in stereo. Try one mic near the 12th fret, and another
near the bridge (Fig. 1-D, 1-E). Pan left and right.
Is feedback or leakage a problem? Mike close to the sound hole with a CM-700 (Fig. 1-F). The tone
there is very bassy, so set the mic’s bass-tilt switch to “Rolloff.” Also turn down the low-frequency EQ
on your mixer until the sound is natural.
FOX TV SPORTS USES CROWN MICS
One TV network doing innovative audio work at sporting events is the Fox network. Last summer,
Fox crews traveled to baseball parks with four Crown PCC-170s (supercardioid boundary mics). They
experimented with placing them in various parts of the outfield walls in ballparks. The PCC-170 also
has been used as a backboard mic in basketball. (But we would recommend the PCC-160 for its
ruggedness and similar sound).
For ice hockey, Fox engineers used PCC-160s taped to the clear plastic shield that protects the audience from the hockey puck. Each mic is up high aiming down at the ice.
TIP FOR MIKING THERAPY SESSIONS
Crown PZMs have been a popular choice for picking up counselors and their clients. A PZM on the
wall picks up the sound, which is fed to a loudspeaker in a nearby room. There, students or other
counselors can listen in on the session.
Speech picked up this way is fairly intelligible. To make the sound even clearer, use two PZMs and
two speakers for stereo. Stereo reproduction helps the listener separate the talkers from the room
acoustics. Two PZMs on the wall about 3 feet apart should do the trick.
PRESIDENTS OF THE U.S. RECORD WITH CM-310As
CM-310A
Grunge-pop trio Presidents of the United States of America recently put out their second album,
recorded at Studio Litho in Seattle. Band member Dave Dederer talked about the mics they used to
record the vocals:
“We did most of the vocal takes at Litho with live vocal mics. We didn’t use fancy studio mics, just the
same ones we used on the road. It was a Crown condenser [CM-310a], and that works for us. It gets
a nice, warm, up-front kinda sound, and you don’t get psyched out the the pop-screen, four-milliondollar mic that you’re totally afraid of.”
Vocalist Chris Ballew agrees. “I hate those [big studio mics]! You can’t put your lips on ‘em! How are
you supposed to sing without putting your lips on the mic?”
Band members recorded most of the album with their lips touching the grilles of the CM-310a Differoid
mics.
SASS STEREO MIC FOR PIANO SAMPLING
In an article in the Nov. 1996 issue of Electronic Musician, author Jim Miller talks about his piano
sampling techniques:
“[One] approach is to position your mics by the player’s head. I’ve had tremendous success with this
technique, particularly when using the Crown SASS-P, which is specially designed to create a strong
stereo image. Although this mic position sacrifices a little in the punchiness department, it captures a
lush, spacious re-creation of what the pianist acutally hears during a performance.
“The Crown Stereo Ambient Sampling Systemhas become myfavorite piano sample.”
KEN WAHRENBROCK
We’d like to quote this article from the Fall 1996 issue of the Syn-Aud-Con Newsletter:
“Ken Wahrenbrock, the developer of the first practical Pressure Zone Microphone (PZM ) and the
driving force behind its adoption by the audio industry, has been paralyzed from the chest down from a
bicycle accident in July.
“Ken traveled with Don and Carolyn [Davis] for several years duing the 1980s and was Don’s indispensable right hand, building innumerable special black boxes for Syn-Aud-Con experiments and
demonstrations.
“Ken made many, many audio friends during those years and it is our feeling that a significant number
of you will want to be in touch with him.
“Ken is now at home. Ken’s address is: 9609 Cheddar, Downey, CA 90242.” [Ken has since passed
away… a great loss. We will miss him.]
TRY A SASS WITH A CAMCORDER
Gary Pillon
Gary Pillon, a soundmixer with General Television Network, has had great success using a Crown
SASS stereo mic mounted on a camcorder. As the photo shows, the SASS attaches to the handgrip,
and provides easy stereo pickup for the video shot.
Gary says that the SASS also could work mounted on a Steady Tracker or Glide Cam, devices which
steady the camcorder shot.
HOW A CARDIOID MIC WORKS
As if by magic, cardioid mics can pick up what they are aimed at, but reject sounds to the side and
rear.
For example, talk into a cardioid microphone from all sides while listening to its output. Your reproduced voice will be loudest when you talk into the front of the mic and softest when you talk into the
rear.
Because they discriminate against sounds to the sides and rear, cardioids help to reject unwanted
sounds such as room acoustics (reverberation), feedback, or leakage. Cardioids are the most popular
choice for this reason.
How do they work? In other words, how do you make a mic directional?
Start by making an omnidirectional mic. Take a mic transducer, made of a diaphragm and some
hardware that changes diaphgram motion into a signal. Then put this transducer in the end of a
sealed can, so that incoming sound contacts the diaphragm only on its front surface.
Sound from the front presses on the front of the diaphgram, and makes a signal. Sound from the side
or rear bends around to the front of the mic. This sound also presses on the front of the diaphgram
and makes a signal. So the mic responds the same to sounds from all directions. In other words, it
has an omnidirectional polar pattern (“omni” means “all.”)
Note that the omni mic becomes directional at high frequencies. That’s because the mic housing
blocks high frequencies that arrive off-axis.
Now suppose we put some holes in the can behind the diaphgram. We carefully size these holes,
and add acoustic damping such as felt or foam, to create an acoustic phase-shift network. It’s like an
RLC circuit, which delays the signal passing through it. The holes, or the “rear ports,” let sound into
the back of the diaphragm. Also, the ports delay the sound reaching the back of the diaphgram.
How does this arrangement cancel sound from the rear? Suppose a sound wave approaches the mic
from the rear. It travels to the diaphgram by two paths: outside the mic, and inside the mic through
the ports (Figure 2).
Fig. 2. Sound-wave travel outside and inside a cardioid mic.
Some of the sound wave travels to the front of the diaphragm, outside the mic. The sound travel time
— from the rear port location to the front — we will call T.
Some sound also enters the rear ports, and is delayed. If the delay inside the mic is set the same as
the delay outside the mic, sounds arrive at the front and rear of the diaphragm at the same time — in
phase. Sounds push on opposite sides of the diaphragm, in phase. The diaphragm cannot move, so
sounds from the rear make a very weak signal. Rear sounds cancel out. You have created a cardioid
polar pattern.
Sounds coming from the front do not cancel out. Why not? Frontal sound waves travel to the rear
ports during time T. Inside the mic, the phase-shift network further delays the sound by time T. The
total delay is 2T. Since there is a big delay or phase shift between the signals at the diaphragm’s front
and rear, a frontal sound makes a strong signal.
High frequencies do not reach the rear of the diaphgram because they are filtered out by the rear
port’s RLC filter. The cardioid mic is directional at high frequencies because its housing blocks high
frequencies off-axis.
How about a bidirectional ribbon mic? The ribbon is fully open to sound on its front and rear. Sounds
from the front or rear experience a phase shift as they travel around the ribbon, so you get an output
signal. But sounds from the side press equally on the front and rear of the ribbon, in phase. The
ribbon cannot move, so you get a weak output from side sounds.
By changing the delay of the rear ports, you can get almost any pattern between bidirectional and
cardioid, such as supercardioid or hypercardioid. Each of these two patterns has a rear lobe that is in
opposite polarity with the front lobe.
###
MIC MEMO
Summer 1997
Bruce Bartlett, Editor
REBA McENTIRE TOURS WITH CROWN CM-311/E’s
Reba McEntire, the “Queen of Country music,” sings through a Crown CM-311/E on tour. The March
’97 issue of Mix magazinedescribed the application:
“Headset microphones, worn by Reba, Linda Davis and three background singers are Crown CM-311/
E’s, with beltpacks by Vega Wireless. An elaborate spare mic system includes ten extra headsets
and a pair of handheld Vegas fitted with Crown heads.”
Reba wearing CM-311E
CM-700 RECOMMENDED FOR ACOUSTIC GUITAR
In the March ’97 issue of EQ magazine, engineer Mike Sokol talks about miking the acoustic guitar:
“For live sound, the challenge is to get enough gain before feedback, so close miking is essential.
Lately I’ve been using the Crown CM-700 with excellent results. Position the mic 4-to-6 inches away
from the strings, and slightly in front of the sound hole.”
CHOIR MIKING WITH PCC’s
Miking a choir is not an easy task. But sound engineer Don Brooks worked out a simple solution to this
complex problem.
Brooks is Director of Technical Ministries for Central Community Church in Wichita, Kansas. He describes
a novel way to mike a choir with PCC-160 supercardioid boundary mics:
“We have 100% converted to PCC-160s for our choir miking. This has been a one-year process as we
experimented with mic location, position, angle, etc.
“Our choir size is 85 to 105 on Sunday, with a live orchestra of 20 directly in front. The orchestra is part of
the problem, and the reason for the PCC-160’s success. The choir sits and/or stands in a choir loft that
has five rows with a 2-foot rise each row. The front row seats 36; the back row seats 18.
“We finally pulled the seven hanging AT-853’s we were using, and are now using only four PCCs (which
may be two more than we need).
“Also, last Christmas we used eight PCC-160s to mike our 38-foot high “singing Christmas tree” with 150
singers, again with great success.”
Fig. 1. Miking a choir with PCCs on stands.
DIFFEROID ON TOUR WITH THE DAVE MATTHEWS BAND
The popular acoustic-pop group, The Dave Matthews Band, has recorded two highly successful CDs:
Under the Table and last years’ multi-Platinum Crash.
Ian Kuhn, monitor mixer for the band, had this to say about the CM-310A Differoid mic used during
their recent tour:
“Drummer Carter Beauford sings into a Crown CM-310A Differoid. A CM-310A is also used for
Moore’s vocal and doubles as his flute mic. The Differoid gives us great rejection and isolates the
sound source, and Beauford definitely likes his vocal screaming.”
Source: Mark Frink, “A Stage-Eye View of the Dave Matthews Band,” Feb. ’97 issue of Mix magazine.
POPLESS MIC ON/OFF SWITCH
Many microphone users want to insert a mute button in-line with a mic cable. With a dynamic mic, all
you have to do is short XLR pins 2 and 3 together to mute the mic. But with a condenser mic, shorting pins 2 and 3 can cause a click or pop.
The cause is phantom-power imbalance. If the phantom DC voltage on pin 2 is higher or lower than
on pin 3, you get a pop when you flip the on/off switch.
Bob Stadtherr, of Bob Stadtherr Engineering, kindly supplied us with a circuit to prevent this problem.
Stadtherr describes the circuit shown in Figure 2:
Fig. 2. Microphone on/off switch.
“This is essentially a lowpass filter, with a cutoff frequency down around 1 Hz (assuming a 150 ohm
mic impedance). The 10K resistor allows the capacitor to charge to the DC voltage between the lines,
so when the switch is closed, no change to the DC levels occurs.”
Thanks for your suggestion, Bob!
MIKE OR MIC?
The spelling of the abbreviation for microphone is not standardized. Webster’s New World Dictionary
says that “mike” is slang for “microphone.” However, mixers are marked “MIC” on their microphone
inputs.
In the Mic Memo we use the following spelling: MIC for the noun form and MIKE for the verb form.
We don’t say “micing” because “c” is pronounced soft (like “s”) if a vowel follows it. We don’t say
“mic’ing” — although that is correct — because it’s cumbersome. We just say “miking,” which is how
it sounds. It’s like saying “biking” instead of “bicing.”
AIR OUT YOUR TRACKS WITH DISTANT MIKING
Close miking is the norm these days, since it gives a tight, punchy sound with lots of presence. Guitar
amps and drums are often miked within an inch or two, sax close to the bell. But there’s an alternative — distant miking — which is a great way to open up the sound of your tracks.
If you want to capture a natural sound on an acoustic instrument, chances are you’ll get it more easily
if you move the mic back about a foot or two. The sound opens up and becomes more natural.
Here’s why. Musical instruments are designed to sound best at a distance, at least 1 1/2 feet away.
The sound of an instrument needs some space to develop. A mic placed a foot or two away tends to
pick up a well balanced, natural sound. That is, it picks up a blend of all the parts of the instrument
that contribute to its character or timbre.
Think of a musical instrument as a loudspeaker with a woofer, midrange, and tweeter. If you place a
mic a few feet away, it will pick up the sound of the loudspeaker accurately. But if you place the mic
close to the woofer, the sound will be bassy. Similarly, if you mic close to an instrument, you emphasize the part of the instrument that the microphone is near. The tone quality picked up very close may
not reflect the tone quality of the entire instrument.
Suppose you place a mic next to the sound hole of an acoustic guitar. The sound hole resonates
around 80 to 100 Hz. A microphone placed there emphasizes this bassy resonance, giving a boomy
recorded timbre that does not exist at a greater miking distance.
In the same way, the sax and clarinet project only the highs out of the bell. The tone holes supply the
warmth and body of the timbre. If you mic close to the bell, you miss the contribution from the tone
holes, and may wind up with a harsh tone quality.
Despite its importance, mic technique seems to be a vanishing art. We can learn from the masters of
mic technique, many of whom made gorgeous recordings with distant mics. Judging from session
photos taken in the 50’s and early 60’s, the engineers used to place the mics at least a foot or two
from the instruments.
The sound picked up this way was natural, and was often better than what we’re recording now. We
tend to be addicted to close miking, not realizing there’s an alternative.
For an example of how good distant mic placement can sound, check out the Dave Brubeck reissue,
Time Signatures — A Career Retrospective. Even though the tapes are 30 years old, they sound
great. Drums have lots of impact; acoustic bass sounds full; piano and sax are warm rather than thin.
On the Brubeck groups, the engineers used one large-diaphragm condenser mic per instrument, and
each mic was at a respectful distance (Figure 3). They usually miked the sax about 1 1/2 feet away
from the keys and bell. Piano was miked just outside the raised lid, with the mic about 1 foot below
the lid. The entire drum set was picked up with one mic placed 5 feet off the floor and 3 feet in front.
String bass was covered by a mic about 1 1/2 feet from the bridge.
Fig. 3. Miking the Dave Brubeck Quartet.
Listen to any record by Led Zeppelin. John Bonham’s bass drum was miked about ten feet away, and
it sounds huge. Check out recordings by Elton John. The engineer often miked the piano several feet
away, overhead.
How can we use those techniques from the past to record better sound in our productions today?
Usually, you can get a natural sound if you place the microphone as far from the instrument as the
instrument is big. That way, the mic has equal pickup of all the sound-radiating parts of the instrument. For example, if the body of an acoustic guitar is 18 inches long, place the mic 18 inches away
for a natural tonal balance. If this sounds too distant or muddy, move in a little closer.
Similarly, try miking a sax about 1 1/2 feet away, about halfway between the tone holes and the bell.
You’ll appreciate the warm, musical timbre you hear at that distance. Of course, you might not want a
natural sound. If you prefer a bright, edgy tonal balance, mic the sax closer to the bell (Figure 4).
Fig. 4. Sax miking tonal effects.
LETTERS FROM CROWN MIC USERS
Miking a church service with the SASS
1. I want to use a SASS-P MKII stereo mic to record our church service, including the P.A. speakers,
as the audience hears it. Where should I place it?
2. Is it okay to add damping to the SASS boundaries? If so, where?
Reply: (1) Try putting the SASS close and up high, near the first row of the congregation, and raised
high enough to not be distracting.
(2) The panels on which the SASS mic capsules are mounted tend to vibrate or ring very slightly,
especially with loud sound sources. You can dampen this vibration to improve the mic’s transient
response. Glue some urethane foam or Soundcoat damping compound to the inside of the boundaries. As long as you do not damage the capsule wiring, adding damping does not void the warranty.
Soundcoat’s phone number in New York is 516-242-2200, and in California is 714-979-9202.
CM-700 great for live gigs
I went to see the band Motorhead. They were using an AKG D-112 to mike the bass amp, but
couldn’t get the snap they wanted. The next night they used a Crown CM-700 [cardioid condenser] I
lent them. They bought one. We use the CM-700 for live work often, as it works well for kick, bass,
overheads, hi-hat, and brass. Great mic. Thanks.
Ed Andrews, Pollen Sound & Lighting, Weirs Beach, NH
Strange sounds in train recording
I was recording a train passby with a Crown SASS-P MKII stereo mic. I heard some “ticking” or “buffeting” sounds, even though the recording level was normal. What is this?
Reply: Most likely, it’s wind noise. The train could have caused some turbulence as it passed. Try
using the supplied windscreen, especially when you record outdoors.
PCC floor isolation
I need to figure out a good way to provide some isolation against vibrations for PCC and PZM type
mics.
Thomas Boisseau, Sound Works, Conyers, GA
Reply: Interesting you should mention that, Thomas, because the PCC and PZM have very little
pickup of mechanical vibrations from the floor. The PCC’s mic diaphragm is perpendicular to the floor,
so vertical vibrations do not make the diaphragm move. The PZM’s mic diaphragm has very low
mass and is highly damped, so it is not responsive to vibrations.
To prove it to yourself, record someone stomping on the floor. As they are stomping, lift the PCC or
PZM off the floor. There is almost no change in the sound. The mics pick up the foot steps acoustically through the air, just as your ears do. But they pick up almost no mechanical vibration through
the floor.
If you want to isolate the mics anyway, try four small pieces of foam rubber, one in each corner of the
mic. The smaller the surface area of the isolator, the better it isolates. Because the mic will be raised
above the floor slightly, the frequency response will be degraded with an upper-midrange dip.
GLM praise
Hey, the polar response of the GLM-100 at all frequencies is great! And the response is flat and
smooth. Keep up the good work.
Chris Griffin, Middleton, WI
PZM PIONEER NEEDS YOUR THOUGHTS
Ken Wahrenbrock built the first commercial version of the Pressure Zone Microphone. He also edited
the PZM Memo, and was an active participant in Syn-Aud-Con seminars.
Ken had a serious accident which left him disabled. According to Ken, “My active life came to a
screeching halt with an accident on my bicycle. Unknown to me, my front wheel was loose, and when
I pulled the front fork up as I entered a parking lot, the wheel disconnected. I went over the handlebars and hit the ground, causing spinal cord hyperflexion at cerbral vertebrae 5, 6 and 7.
“The result was I became a quadriplegic. I have some use of my right arm, but only a little use of the
left, which is also weaker. I have no control of the my fingers. The neurosurgeon we consulted for a
third opinion agreed that the condition is permanent.
“Important lessons reinforced: You just never know... Enjoy what you can enjoy while you can enjoy
it... You don’t get it the way you want it; you get it the way you get it... Take one day at a time... Just
put one foot in front of the other... If it makes you cry, don’t think about it... There’s no substitute for a
sense of humor... Just do the best you can every day.”
Please include Ken in your thoughts and prayers. He and his family are grateful for the many people
around the country who continue to contribute to their well-being.
Please send any donations to the Ken Wahrenbrock Fund, Syn-Aud-Con, 8780 Rufing Rd.,
Greenville, IN 47124. Check, Visa, or Master Card are welcome. If you’d like to write, Ken is at 9609
Cheddar St., Downey, CA 90242-4928. [Ken has since passed away – a tragic loss.]
###
MIC MEMO
Fall 1997
Bruce Bartlett, Editor
A BOUNTY OF NEW HEADWORN MICS
Crown is happy to announce SIX new headworn mics. Compared to our previous models, the new
models offer these advantages:
*Carrying case.
*New slim battery pack with easy access to the battery.
*Mic on/off switch programmable for push-on/push-off, push-to-talk, or mute.
*A more-rugged boom mount.
*Boom 1 inch longer to accommodate larger heads.
*New high-performance windscreen with some models.
*Wireless models now work down to 3 volts.
CM-311A
Let’s briefly describe each new model:
CM-311A: Headworn Differoid mic with a battery beltpack. The mic is in front of the mouth.
CM-311AHS: Same as CM-311a, but mounts on a Sony MDR-7506 headphone.
CM-311A/E: Wireless version of the CM-311A; runs off 3-9V from a transmitter of your choice.
CM-312A: Headworn hypercardioid mic with a battery beltpack. The tiny mic is to the side of the
mouth.
CM-312AHS: Same as CM-312A, but mounts on a Sony MDR-7506 headphone.
CM-312A/E: Wireless version of the CM-312A; runs off 3-9 V from a transmitter of your choice.
HANG ‘EM HIGH
Want to permanently hang a SASS stereo mic? Try running a pipe straight down from the ceiling to
the SASS, which you mount upside down. Both ends of the pipe should have a 5/8"-27 thread. One
end screws into the SASS swivel mount; the other end screws into an Atlas AD-11 flange that bolts to
a ceiling beam.
Being upside down does not affect the SASS’s sound. Just be sure that the left and right channels
are not audibly reversed.
STOP THUMPS WITH NEW SHOCK MOUNTS
Does your lectern mic go “bong” when someone drums on the lectern surface? Solve the problem
with the LM-SM shock mount, which isolates Crown lectern mics from mechanical noises. This flat
rubber disk mounts in a lectern, pulpit, or table top. The rubber isolator is more stable than elastic
bands, and the mount prevents theft by securely holding the mic in place. Installation is quick and
easy.
CM-SM shock mount
Also available is the CM-SM, a mic-stand adapter that isolates a CM-700 microphone from mechanical vibration. It will also work with other 3/4" diameter mics that are similar to the CM-700 in weight
and size, such as the Crown TEF-05 [Now the CM-150] omni studio mic.
Because of its elastic suspension, the shock mount reduces stand and floor thumps by at least 22
dB (A-weighted). A thumbwheel on the shock mount lets you clamp the mic cable. This keeps the
mic oriented corrently and prevents cable noise from reaching the mic.
NEW MINI-BOUNDARY MICS EASE INSTALLATION, CUT COSTS
Just introduced from Crown is a series of five miniature boundary mics for multi-miking on conference
tables. Other uses are teleconferencing, security, distance learning, boardrooms, and courtrooms.
The mics are nearly invisible: each is approximately the size of a silver dollar.
Fig. 1. MB series.
All MB series mics feature a surface-mounted supercardioid capsule for extended reach and a clear,
natural sound. With 70 dB attenuation in the off position and low self-noise, quiet is guaranteed even
when multiple mics are in use.
Some of the mics (MB-1, MB-2, and MB-4/E) are used with an MB-100 or MB-200 interface, which
mounts unobtrusively under the table top. The interface powers up to four mics, and has programmable switching to turn the mic on or off if desired (switches not provided). The MB-200 interface also
has remote switch-closure sensing via an optical coupler.
An installation using an MB interface and four MB mics can save up to 30 percent compared to standard individual microphones.
The wide variety of mic styles lets you mix and match as needed for several configurations. Let’s look
more closely at each mic model.
The MB-1 plugs into a table-mounted jack. Supplied with the mic is a brass table insert with a phone
jack that accepts the mic. The insert flush-mounts in a hole drilled in the table. After meetings you
can remove the mic and cover the insert with the provided brass disk.
A rectangular microphone, the MB-2 has a bottom-mounted phone plug. It plugs into a stereo phone
jack previously installed in the table. The contractor supplies the phone jack, which is a Switchcraft
152B Thick Panel Phone Jack or equivalent.
The MB-3 circular mic permanently installs into a hole drilled in a table, wall, or ceiling. On the bottom
of the mic is a tubular power module with an XLR-type output connector.
Don’t want to drill into the conference table? Try the MB-4. This rectangular mic has a 15-foot attached cable leading to an XLR-type connector with powering electronics. The MB-4/E is the same,
but without the electronics/connector. The MB-4/E is used with the Crown MB-100 or MB-200 interface.
HANSON POP GROUP USES CROWN CM-311A
Zac Hanson wearing a CM-311A
The young recording group, Hanson, is something of a pop phenomenon. Aged 11, 14, and 16, they
had a top-ten album with Middle of Nowhere. Their single “MMMBop” was No. 1 for three weeks.
Shown in the photo is drummer Zac Hanson, who uses a Crown CM-311A headworn mic on tour.
Source: People magazine, 7-7-97.
MIC MEMO NOW ON THE WEB
The Mic Memo is also on the Crown Web Page. Our Web site address is http://
www.crownintl.com.
COMPACT CONFERENCE MIC FEATURES ON/OFF SWITCH
Measuring only 3.5" x 2.5", the Crown PCC-130SW is a surface mounted supercardioid mic of top
quality. This handsomely styled unit is appropriate for use on the most elegant boardroom table or
lectern. Other applications include distance learning, teleconferencing, courtrooms and council chambers.
PCC-130SW
Thanks to its half-supercardioid polar pattern and surface mounting, the PCC-130SW offers a clear,
natural sound with excellent articulation.
On the front of the mic is a silent-operating membrane switch which is normally off. You can program
the switch for touch on/off, momentary on or momentary off. The mic is intended for multi-mic use on
a conference table where each person wants control of his or her microphone.
RFI suppression is included. Self-noise is low and sensitivity is very high. A bass-tilt switch lets the
user tailor the low-end response.
SASS AND CAMCORDER MAKE A PERFECT PAIR
The SASS-P MKII stereo mic is an ideal mate for the new low-cost pro-sumer camcorders. Thanks to
the SASS, it’s easy to record a stereo soundtrack with superb imaging. Just connect the SASS upside down to the camcorder.
Who came up with this idea? Gary Pillon, a location soundmixer for General Television Network.
He’s also a columnist for Michigan VUE, a magazine about video production in Michigan.
In his column, Sound Advice, Gary said, “Why is a location soundmixer excited about a new video
format? [Your] projects [can] link the power of a good video camera with the 360-degree soundfield of
a stereo microphone. The secret ingredient that makes this idea so successful is mounting the camera and stereo mike on a Steadicam platform. The rig becomes a virtual representative of the operator, seeing and hearing surrounding events in a matched audio-video perspective.”
SASS/camera
“[Small, lightweight] consumer cameras... can be mounted on an inverted stereo mike like the Crown
SASS-P MKII. New handheld stabilizers, like the Glidecam ©3000 Pro and Steadytracker ©
Flightstick, offer mounting platforms for any of the new-generation stereo mics, such as the SASS-P
MKII.”
PZMS ON A BUDGET
Redesigned for the ’90s, the Sound Grabber II and PZM-185 are low-cost Pressure Zone Microphones. They are designed for general-purpose use such as conferences, group discussions, interviews, home video, lectures, and music recording.
The Sound Grabber II is powered by an internal 1.5V battery. The boundary “paddle” can be removed
so the mic will fit in your pocket. Attached to the mic is an 8-foot cable with a mini phone plug. Output
is medium-Z unbalanced.
PZM-185
Similar in size and shape to the Sound Grabber II, the PZM-185 also has a removable boundary
“paddle.” The mic runs off phantom power or an internal 1.5V battery. Output is low-Z balanced.
Both mics offer the same clear sound and freedom from phase interference that makes PZMs so
useful.
CROWN MICS: IN THE BEGINNING
The 17-year history of Crown microphones has an intriguing beginning. Someone approached Crown
and asked them if they wanted to manufacture a radically new microphone that nobody else was
making. It was called the Pressure Zone Microphone, or PZM.
The PZM started as a mic technique, not a product. It all began in 1978. Audio consultant Ed Long,
and recording engineer Ron Wickersham, came up with an unsual concept: they mounted a small
microphone face down very close to a surface. This gave a very clear, natural sound quality by eliminating phase interference from surface reflections.
Ken Wahrenbrock, a graduate of the Syn Aud Con audio seminar, developed the first PZM prototype.
He mounted a miniature hearing-aid mic face down next to a plate. He marketed these mics on a
small scale.
In 1980, Ken approached Crown with his invention. We agreed to manufacture and market the PZM.
Crown engineers gave the PZM a facelift so that it looked slick and professional. That was the only
mic Crown made back then.
When PZMs were first introduced at the Audio Engineering Society, they were controversial and
caused a great stir because they were so different. Eventually they caught on, and now almost every
other microphone company makes their own version.
Since then, Crown developed several new types of PZMs, PCCs, and all sorts of other microphones.
The SASS was the only other microphone that started from an outside inventor; the rest were developed here. But the microphone product line all started with the Crown PZM. It may look funny, but it
sounds great.
LETTERS FROM CROWN MIC USERS
Differoid Delights
I do a lot of live sound for broadcast. When the CM-310A came out I bought one right away and put it
to work in one of my most challenging venues. It worked well, so I bought three more and made sure
I always had one in my case, at least as a backup. But the CM-310A’s are such good problem solvers, I have found that my other mics don’t see so much daylight anymore.
D. Peter Maus, Maus Productions, Chicago, IL
###
MIC MEMO
Winter 1998
Bruce Bartlett, Editor
CM-700 SHOOT-OUT
CM-700
“I was shocked to hear that Crown made anything besides the Garth Brooks headset mic or PZMs. I
assumed that the CM-700 at $289 was a cheap mic; it couldn’t sound good. But it smoked the muchmore expensive mic I tried on acoustic guitar.”
So said Randy French, a recording engineer/producer for Randy French Sound Labs in Michigan. He
recently compared the Crown CM-700 cardioid condenser mic to an AKG 414-TL2 costing several
times as much. The AKG unit is a large-diaphragm microphone with a C-12 mic capsule.
Randy tells the story:
I thought it wasn’t a fair comparison, but I decided to do it anyway because a lot of people like to use a
414-TL2 on the acoustic guitar. I plugged the mics into a $2,300 API mic preamp and recorded them
straight to a DAT. I miked the guitar 8 inches away at the 12th fret, but also miked it every crazy way
you could think of.
Playback in mono was over a pair of UREI 809’s and KRK 7000’s. It was a blind test. I started
punching back and forth between the two mics. When the first mic came up, I said, “That’s my TL2.”
I recognized it. The second mic sounded a little distant and kinda boxy. Didn’t have quite the focus
and brightness. I said, “Well, this test is over with; I already know which one is the TL2.”
I was listening for transients, top end. I want something with a real breathy, airy top end to it.
At the end of the test I tapped on each mic to identify them. Guess what? I got ‘em backwards! I
was blown away; I didn’t believe it. So I redid the whole test and identified them for sure. The CM700 on that acoustic guitar smoked the other mic. It was pretty much a slam dunk. A huge difference.
Not that the TL2 sounded bad, but the CM-700 was much clearer, purer, focused, and quicker-sounding. The TL2 had a blurrier, more distant sound.
I checked the CM-700 with drums and cymbals. No breakup. When hung over cymbals, compared to
a 414 and a U-87, the 700 sounded so similar that it was just a matter of preference or taste. On the
bell of the cymbal, the 700 blew the rest away; it was purer and cleaner. I thought, “There’s no way
this inexpensive mic could sound this good.”
Mics with 1-inch diaphragms, like the TL2, tend to sound bigger but muddier around 300-400 Hz.
On vocals, the CM-700 sounded too bassy up close (I didn’t use the built-in bass rolloff switch). But
at 1 foot versus a U-87, I was pleasingly surprised. I did not prefer the 700 but it had a very present
sound. At 2 feet from the singer, like for a choir or backup vocals, the 700 was right in the ballpark
with the other mics.
The only complaint I have is: It makes me mad that I spent as much as I did on some other mics!
CONCERTINA MIKING WITH GLMS
Musician Rich Rys came up with a novel and effective way of miking his concertina.
Using rubber bands, he attached a GLM-100 mini omni mic on the inside of each forearm near the
wrist (Fig. 1). Each mic is about 5 inches from the concertina grille holes. Rys put electrical tape over
the grille holes nearest the mic to soften them.
Fig. 1. Concertina miking with GLMs on wrists.
According to Rys, the GLM-100 gives an even pickup and clear sound, but perhaps not enough gainbefore-feedback. He substituted the GLM-200 hypercardioid and solved the feedback problem.
PZMS FOR STEREO PIANO
John Hampton is a prominent recording engineer who has worked with such greats as B.B. King,
Travis Tritt, Lynyrd Skynyrd, Robert Cray, the Bar Kays, the Gin Blossoms, and many of Nashville’s
most succesful country artists.
In the November 1997 issue of Mix magazine, Hampton described his piano miking techniques:
“A piano was meant to be heard phase-coherently. When you listen to a piano, you’re hearing the
piano hammers hitting the strings, and the sound reflecting off the lid and coming to your ear.
“My favorite method is to put two PZMs back to back — just tape them together. I will put them 12 to
15 inches above where the hammers hit the strings. They need to be the kind of PZMs with the highfrequency boost [PZM-6D or PZM-30D]. With those, you never need to EQ the piano.
“[That is one way] that I have recorded piano and consistently experienced the most satisfying results.”
LIVE ROCK RECORDING WITH CM-311As
Recording engineer Mark Darnell played me his tape of a rock band, recorded live to 2-track in the
studio. The sound was so tight (free of leakage), I thought it was done with overdubbing. But Darnell
had recorded all the instruments and vocals at the same time.
His secret? Use CM-311A Differoid headworn mics on the singers. These mics have so much isolation, there is almost no leakage in their signal. The tone quality of these mics works well with rock
production.
Figure 2 shows the studio layout. Three guitar amps were miked with Crown CM-700s, the keyboard
was direct, and a PCC-160 captured the kick drum. The keyboardist and drummer sang live through
their CM-311A mics. All the musicians monitored each other through headphones.
Fig. 2. Studio layout for live recording.
HOW TO AVOID COMB FILTERING
When you’re forced to hang a stereo mic near a ceiling, you might get phase cancellations from ceiling sound reflections. Sound arrives at the mic via two paths: direct from the source, and delayed off
the ceiling (Fig. 3). The direct and delayed sounds combine at the mic, causing phase interference
and a colored tone quality.
Fig. 3. Ceiling reflections.
Rex Garrett, a sound engineer with Showorks, devised a mic placement near the ceiling that is free of
coloration. In one application, he hung a SASS stereo mic 10 feet from the ceiling. The resulting
delay from the ceiling reflection is too short to make an echo, but too long to make serious comb
filtering. According to Garrett, hanging the mic 10 feet from the ceiling removes the sound of the
ceiling.
MIKING A FLUTE RECITAL
Reader Stan Larson wanted to record a recital of a flute and grand piano in a church. His recording
machine was a cassette multitracker. Stan said that he wanted to control the relative levels of the two
instruments, and asked if we had any miking advice.
One suggested method is to mike the piano and flute up close, and also mike the room for ambience.
On the piano, try a PZM-6D taped to the underside of the raised lid. On the flute, use a CM-700
cardioid condenser about 1 foot away, midway between the mouthpiece and tone holes. Aim the
“dead” rear of the flute mic at the piano.
Also, place a couple of mics back in the hall to pick up room reverb.
Feed the piano and flute mics to tracks 1 and 2, and feed the room mics to tracks 3 and 4. During
mixdown, adjust the balance between the instruments, and mix in the desired amount of hall ambience.
Another method is the usual way of recording classical music: a stereo mic pair several feet out front.
Try mounting two CM-700 mics as an ORTF array: angled 110 degrees apart and spaced 7 inches
horizontally. Place the mic pair about 4 to 15 feet away — closer for more presence; farther for more
hall sound.
That method leaves the balance up to the musicians rather than the recording engineer.
CARRYING CASES FOR CM-311/CM-312 MICS
Crown now offers a storage/travel case for the CM headworn microphones. The new CM-311A and
CM-312A models come with the case included. Those who have the older microphones can buy the
case from our parts department: Crown Part No. 125127-1, cost $25.00.
INCREASING GLM-100 GAIN-BEFORE-FEEDBACK
David James, an award-winning fiddler and guitarist, came to Crown to explore ways to make his
GLM-100 louder through his PA system. (The Crown GLM-100 is a mini omni mic.)
These mic positions worked well:
Fig. 4. Fiddle miking with the GLM-100.
Guitar: Attach the lavalier clip to the sound hole. Place the mic under the strings, with the front of the
mic looking at the strings. With some bass rolloff, the sound is natural.
Fiddle (natural sound): Attach the lavalier clip to the bridge. Place the mic aiming down at the body
about 1/4" away (Fig. 4)
Fiddle (loudest sound): Place the mic inside an f-hole, with the cable wedged into the narrow part of
the f-hole (Fig. 4). For cable strain relief, trap the cable under a rubber band stretched around the
fiddle. This method needs some EQ to sound natural; try cutting at 100 Hz and 3 kHz.
CM-700 REVIEW
In the Spring 1997 issue of Tape Op was this review of the CM-700 cardioid condenser mic:
“I’ve been using this mic for recording the snare during basic tracks and lead-vocal tracks during final
overdubs. It’s amazing that one mic could be great on both. It has many other uses too, like for
capturing the ugly glory of a death-metal Marshall guitar cabinet, violin overdubs, and Indian hand
drums. I find it to be one of the most versatile mics I’ve ever used and sometimes wonder how I
recorded without one.”
CLEAR PLASTIC PCCs PROVIDE AUDIO AT OLYMPICS
If you don’t see any mics at the Olympic hockey games this winter, they are Crown mics! We were
asked to design some “invisible” PCC-type mics that had to withstand being hit by a hockey puck.
Fox TV network had tried Crown PCC-160 supercardioid boundary mics to pick up hockey games.
They taped the PCCs to the clear plexiglass barrier that shields the audience from stray hockey
pucks. But the mics looked too big. Fox engineers asked Crown to make the mic base of clear Lexan
so that the mic would disappear.
Also, Crown added internal braces to strengthen the housing against strikes by hockey pucks.
Phil Adler, a freelance audio mixer, was using clear PCC’s for hockey games broadcast by ESPN.
This winter in Nagano Japan, Adler will mix the Winter Olympics hockey games using eight of those
mics.
“I love these things,” says Adler. “On camera all you see is the narrow mic cover; it looks like a black
line. You don’t even notice it. The mics allow me to get incredible audio. Fox loves them too.”
Adler tapes the PCCs to the inside of the hockey-puck barrier with clear shipping tape.
When you watch the Winter Olympics, listen for great sound from mics you can’t see.
LETTERS FROM CROWN MIC USERS
SASS-happy
I have been using the Crown SASS-P microphone for several years for live orchestra and for recording. In fact, we are recording the Moller pipe organ in the the fabulous Fox Theatre in Atlanta as I am
writing this. The Crown SASS microphone is great.
Jess McCurry, Fox Theatre, Atlanta, GA
Mic vs. Mike
Thank you for your thoughtful and rational discussion of the abbreviation for microphone (Summer
1997 issue). I look forward to other articles relating to standardization and consistency. A key factor
in the design of systems and products that meet Human Factors Engineering (Ergonomic) criteria is
consistency, and designing to meet the needs, expectations, habits, and performance characteristics
of the user.
Andrew D. Keller, CPE, Keller Professional Ergonomics, Longmont, CO
Mic techniques, voice directivity
1. In some future issue, could you show preferred mic locations for instruments? I feel that others,
besides myself, would be greatly interested in that subject.
2. Has anyone published a series of patterns showing how a person’s voice projects from their mouth
at various frequencies? I believe that every audio operator and consultant could do a better job of mic
placement if they had such information and could compare it to data on microphones.
Patrick J. Utecht, Satellite Beach, FL
Editor’s reply:
1. Crown has published a series of microphone application guides. They are free from Crown or your
Crown dealer. Titles include:
*CM, LM and GLM series
*Studio recording
*Boundary mics
*Speech sound reinforcement
*Houses of worship
*Video
*Schools
*Teleconferencing and Distance Learning
2. One source of voice directional patterns is the classic text Acoustics by Leo Beranek. Figure 5
(from that book’s Fig. 11.12) shows directivity patterns for the human voice.
Fig. 5. Voice directivity patterns.
Note that the high frequencies are diminished off-axis to the mouth. So choir mics hung above the
mouth should have a rise at high frequencies to compensate. The Crown CM-30 and CM-31 choir
mics have such a frequency response.
###
MIC MEMO
Spring 1998
Bruce Bartlett, Editor
EASY CHOIR PICKUP WITH MINI BOUNDARY MICS
Crown’s tech-support wiz, Mark Chapman, told me about a unique application of the MB-4 Mini
Boundary Mic. The MB-4 is a miniature supercardioid mic meant to be used on surfaces.
Here’s the application: a church choir had to be situated under a balcony, so the ceiling was low over
their heads. There was no place to hang conventional mics without picking up phase interference
from ceiling reflections.
The church’s sound engineer solved the problem. Using double-sided tape, he attached two MB-4’s
to the ceiling in front of the choir (Fig. 1). Then he ran the mic cables behind the edging.
Fig. 1. MB-4 miking a choir under a balcony.
According to the sound engineer, the choir’s sound was much louder and more natural than it had
been in the past. Plus, the mini boundary mics are invisible in use.
CROWN MICS FEATURED ON GUITAR CD
Will Rogers, a skilled New Age guitarist, used Crown mics exclusively to record his recent CD, Freeing the Soul.
To quote his liner notes, “Thanks... for the prototype Crown microphones I beta-tested and could
never return — thanks guys for the most impressive mic system for acoustic guitar I have ever recorded — this sound would not have been possible without the stereo GLM-200’s and the Crown CM700 and PZM.”
CD album cover
Played with technical virtuosity, Rogers’ music is peaceful and meditative. It features acoustic guitar,
electric guitar, and percussion.
Rogers sent us the following note with the CD: “The Crown CM-700 and GLM-200 guitar mics (with
their EQ disabled) are really terrific. I have been using them exclusively since discovering their intimate tone and clarity. I often use just two GLMs in stereo for the close-mic guitar sound. This album
has won an ASCAP award and I feel the Crown mics were definitely a part of that.”
The CD, Freeing the Soul, # 11-17-1, is available from the labelOversoul Music, phone 213-650-3698
or 213-654-7740.
MAINTAINING YOUR MICS
Chances are you have several great-sounding mics in your collection. You want to keep them in top
condition; otherwise their sound can degrade over time. Here are some tips on maintaining your mics
so they will always sound like new.
The best maintenance is preventive. If you protect your mics from environmental pollutants, that is
the best insurance against loss of performance.
The air is full of contaminants such as dust and cigarette smoke. These can settle on the diaphragm
and degrade its frequency response. What’s more, breath moisture and humidity can short out the
high-impedance parts of condenser mics, causing thin bass or crackles. Let’s look at several ways to
keep pollutants out of your mics.
Use a pop filter: Although the main use for a foam pop filter is to reduce plosives, the filter also
shields the mic diaphragm. Breath moisture and food particles have a hard time making it through the
filter.
Caution: pop filters are made of polyurethane foam, which can decay over time. Old windscreens
slowly turn to powder which may collect on the diaphragm. Periodically replace old filters with new
ones.
Hoop-type pop filters made of nylon fabric also shield vocal mics from mouth particles.
Keep mics covered: If you leave a mic on its stand without a cover, dust settles on the mic capsule
and gradually degrades its response. This is easy to prevent. Your mics came with protective
pouches or carrying cases. After each session put the mics in their pouches or cases. For long-term
storage, put them in a closet or cabinet.
Don’t blow on mics: Blowing on a microphone for a mic check is a no-no. Doing so can force
particles through the grille screen and onto the diaphragm. In many mics, the diaphragm is made of
very thin metal foil. A breath blast can bottom out the diaphragm onto the backplate, causing a spark
which can perforate the diaphragm. Ribbon mics are especially sensitive to damage by breath pops.
To test a mic, simply talk into it or scratch the grille.
Upgrade older mics: Do you suspect that an older mic does not sound like it used to? Do you have
a vintage mic that you want to upgrade? Send it either to the manufacturer, to your mic dealer, or to a
person who specializes in vintage-mic upgrades, such as Stephen Paul.
For a nominal fee, the mic manufacturer will run a response curve, check the noise floor, and so on.
Then they will replace or clean the mic capsule at their discretion. They will also check the electronics
and replace aged components if necessary.
This maintenance takes skill and specialized equipment. Do not attempt to repair the mic yourself, or
you may damage it worse than when you started. Usually it is safe to solder on a wire that has broken
loose, but other circuit changes are not recommended. Some electronic components might have
been selected for tight tolerances or low distortion, so a replacement may not work correctly. Some
circuit parts may have been coated to keep out humidity, and soldering them destroys this protective
coating.
Mic rentals: If you rent microphones for occasional use, you don’t always know what shape they are
in. The rental house may have maintained their stock, but perhaps not. Ask.
When do you need service? How do you know whether a microphone no longer has its original frequency response? One way is to compare it to a new mic of the same model number. Set up a talktest comparison, either live or recorded, and listen for tonal differences between the two mics. Place
them the same distance from your mouth and match their levels carefully.
Caution: Two new mics of the same model may sound slightly different due to production tolerances.
With most microphones, the response is allowed to vary +/- 2 dB from one unit to the next. But if you
hear an extreme difference, it’s time to have the microphone repaired.
If you have access to a sound analyzer (such as the Goldline TEF-20), you can measure your mics’
frequency response. Test a microphone when it is new and print out a response curve. Then test the
same mic periodically with the same setup to see whether the response has changed. Follow this
procedure:
1. If possible, use a coaxial speaker so that all the sound arrives on-axis to the mic.
2. Place the mic on a stand exactly 1 foot from the speaker, on-axis to the tweeter.
3. Place the mic and speaker several feet from the walls, ceiling, floor, and other reflective surfaces.
4. Set the frequency resolution to 300 Hz to keep sound reflections out of the measurement. Then the
lowest frequency you can measure accurately is 300 Hz. Ignore data below 300 Hz.
5. Run a frequency sweep and print out the response curve.
NOTE: This curve includes the response of the loudspeaker, as well as the mic. Some software lets
you measure the speaker first with a flat omni mic. Then the software subtracts the speaker response
from subsequent measurements. This leaves the response of the mic itself.
We looked at some ways to test mics for degraded response, and offered some tips on preventive
maintenance. With a little care, your microphones will keep their original performance for a long time.
HISTORY OF THE SASS MICROPHONE
In the summer of ’89, Crown introduced a new kind of stereo microphone that the world had never
seen before. It was called the SASS, or Stereo Ambient Sampling System.
SASS-P MKII in use outdoors.
The SASS uses two PZM microphones on small panels, separated by a foam barrier. The two mics
are spaced as far apart as our ears, and the foam barrier acts something like a head. So the SASS
produces very realistic stereo recordings. If you record an orchestra with the SASS, you can hear
exactly where each instrument is located, and you can hear all the ambience and reverb of the concert hall. The SASS also works great for recording sound effects in stereo.
The SASS was invented in 1989 by a recording engineer named Mike Billingsley. He approached
Crown about developing and marketing his invention. We worked with Mike to develop the SASS into
a professional product.
In the Spring of 1989, a group of microphone people went to the European Convention of the Audio
Engineering Society to reveal the news about the SASS mic. We also presented papers on the theory
and application of the SASS mic.
To test the SASS, we recorded the London Philharmonic. We also recorded Lenny Kravitz’s drummer, Zoro, and the Indy 500 racecars. Crown put out a demo CD of the SASS.
The current version of the SASS is the SASS-P MKII. It gets a lot of comments at trade shows, not
only because it looks unique, but also because it works so well.
EFFECT OF BOUNDARY PLATES ON CONVENTIONAL MICS
Can you improve the rear rejection of a standard microphone by mounting a boundary plate behind
the mic capsule? That question was asked by Steven Crispiano, a sound engineer for NBC News.
He sent us several types of mics to test, along with some round plexiglass plates ranging from 8" to
10" diameter.
We measured the frequency response and off-axis rejection of each mic before and after adding the
plate. Here are the results:
The general effect of the boundary plate on the mics is:
1. Rougher response, especially on axis.
2. More directionality at high frequencies.
3. Less directionality (more omni) at low frequencies.
Here’s the effect of the boundary on each mic:
Handheld omni: Much rougher on-axis response due to delayed reflections off the boundary. The
boundary is not in the same plane as the mic diaphragm, so delayed reflections off the boundary
cause phase interference. The mic becomes more directional from 300 Hz up, especially at high
frequencies. It becomes sort of a supercardioid.
Short shotgun: The on-axis response becomes rougher but probably doesn’t sound bad because the
peaks and dips are so narrow. The 90-degree curve is about the same, but the rear null shifts from
180 degrees to 125 degrees and becomes deeper. The boundary makes the mic a little more directional at the expense of smooth response.
Cardioid dynamic: The on-axis response becomes rougher and the off-axis response becomes
worse — more omni. A boundary is not recommended with this mic.
Crown CM-200A cardioid: See Figure 2. The on-axis response becomes rougher. The off-axis
response becomes more omni up to 4 kHz, then becomes more directional above 4 kHz (Fig. 2)
Fig. 2. Crown CM-200A without plate (top) and with plate (bottom).
Summing up, the plate can make an omni mic more directional (for better background noise rejection)
at the expense of natural reproduction. The plate makes the shotgun a little more directional, but
degrades the performance of the cardioid mics.
LAVALIER MIKING TIPS
A popular way to mike a stage play is with wireless lavaliers and PCC-160 stage mics. Crown’s CM10/E and GLM-100/E lavalier mics are good choices for this application. Here are a few ways to get
the best results from them.
CM-10 omni lavalier mic.
*Try to stick with one model of mic for consistency.
*Lavaliers sound much more natural just above the breastbone than at the throat area.
*If the mic is inside a shirt, tape the mic to the shirt to prevent cable noise. Use fresh gaffer’s tape or
surgical tape.
*Metal-bodied mics can create a shock hazard. The plastic housing of the CM-10 and GLM-100
prevents this problem.
*You can conceal the mic in the knot of a tie. Wrap the mic in toupee tape before hiding it in the tie
knot.
*Other places to hide the mic are in a wig, hat, glasses, or in the hair. Be sure to strain-relieve the
cable behind the neck.
*To reduce cable noise by several dB, tie a loose knot in the cable a few inches from the mic. Strainrelieve the cable at the collar or belt.
*Ask the actor or actress to help you string the cable through their costume.
*The wardrobe department can make mic belts or pockets to hide wireless transmitters.
*Several layers of clothing can generate noise when they rub against each other. You might ask the
wardrobe department to secure the layers temporarily with needle and thread.
*Attend wardrobe pre-production meetings. Tactfully ask whether they can avoid noisy clothing, such
as starched, stiff costumes and plastic fabrics.
*Don’t store mics with tape on them, because a gooey residue will build up.
*Periodically inspect the connectors and cables. Wiggle them while listening to the mic output.
*Use fresh batteries at each performance. Do not use rechargable batteries because they do not
always retain their charge.
*Low-frequency cut can help reduce breath pops or cable noise. A high-frequency boost compensates for the mic being covered by thick clothing.
###
MIC MEMO
Summer 1998
Bruce Bartlett, Editor
CONCERTINA MIKING WITH GLM-100s
Concertina miking system
Rich Rys, a prominent concertina player, shared with us his unique method of miking.
Rys uses five GLM-100 mini omni mics on the instrument. Three mics are on the treble side, two on
the bass side. Foam windscreens cover the mics.
Near each mic is a black Delrin plastic rod, 1/2" long and 3/16" diameter. Rys affixes some Velcro
there to attach each mic about 1/2" from the concertina grille.
The five mics are fed into a custom mixer with a high-Z input.
According to Rys, the GLMs pick up no key noise and no air-valve noise. The concertina coverage is
extremely even and clear, with great dynamic range. Rys reports that the mics are durable. He will
purchase a Sabine FBX feedback exterminator to use with the mic array.
SURROUND-SOUND MIC TECHNIQUES
A number of mic techniques have been developed for recording classical music in surround. Let’s
take a look at some of them.
Delos VR2 Surround Miking Method
John Eargle, Delos’ director of recording, developed their VR2(Virtual Reality Recording) format.
Recordings made with this method offer discrete surround. They also are claimed to sound good in
stereo and very good with “steered” analog decoding, such as Dolby Pro Logic.In making these recordings, Eargle uses the mic placement shown in Fig. 2.
Fig. 2. A Delos surround miking method.
This method employs a coincident-stereo mic in the center, flanked by two spaced omni’s typically 4
feet apart. Two house mics (to pick up hall reverb) are placed 30 to 40 feet behind the main pair.
(Greater spacing creates an undesirable echo). These house mics are omnis or cardioids aiming at
the rear of the hall, spaced about 12 feet apart. There also might be spot mics (accent mics) placed
within the orchestra. The mics are assigned to various tracks of a digital 8-track recorder:
1 and 2: A mix of the coincident-pair mics, flanking mics, house mics, and spot mics.
3 and 4: Coincident-pair stereo mic
5 and 6: Flanking mics
7 and 8: House mics (surround mics)
5-Channel Mic Array with Binaural Head
This method was developed by John Klepko of McGill University. It combines an array of three directional mics with a 2-channel dummy head (Fig. 3).
Fig. 3. The Klepko surround miking method.
Front left and right channels: identical supercardioid mics Center channel: cardioid mic Surround
channels: dummy head with two pressure-type omni mics fitted into the ear molds. The mics are
shock mounted, and have equal sensitivity and equal gains. Supercardioids are used for the front left/
right pair to reduce center-channel buildup.
Although the dummy head’s diffraction causes peaks and dips in the response, it can be equalized to
compensate.
During playback, the listener’s head reduces the acoustical crosstalk which would normally occur
between the surround speakers.
According to Klepko, “The walkaround tests form an image of a complete circle of points surrounding
the listening position. Of particular interest is the imaging betwen +/- 30 degrees and +/- 90 degrees.
The array produces continuous, clear images here where other (surround) techniques fail.”
“The proposed approach is downward compatible to stereo although there will be no surround effect.
However, stereo headphone reproduction will resolve a full surround effect due to the included binaural head-related signals. Downsizing to matrix multichannel (5-2-4 in this case) is feasible except that
it will not properly reproduce binaural signals to the rear because of the mono surrounds. As well,
some of the spatial detail recorded by the dummy-head microphone would be lost due to the usual
bandpass filtering scheme (100Hz-7kHz) of the surround channel in such matrix systems.”
DMP Method
DMP engineer Tom Jung has recorded big-band jazz in surround using a Decca Tree stereo array for
the band and a rear-aiming coincident stereo mic for the surround ambience (Fig. 4). Spot mics in the
band complete the miking. The Decca Tree uses three mics spaced a few feet apart, with the center
mic placed slightly closer to the performers. It feeds the center channel in the 5.1 system.
Fig. 4. A DMP surround miking method.
Woszcyk Technique (PZM Wedge Plus Surround Mics)
A recording instructor at McGill University, Wieslaw Woszcyk developed an effective method for
recording in surround that also works well in stereo. The orchestra is picked up by a PZM wedge
made of two 18"x29" hard baffle boards angled 45 degrees. A mini omni mic is mounted on or flush
with each board. At least 20 feet behind the wedge are the surround mics: two coincident cardioids
angled 180 degrees apart, aiming left and right, and in opposite polarity (Fig. 5).
Fig. 5. Woszcyk surround miking method.
According to Woszcyk, his method has several advantages:
*Imaging is very sharp and accurate, and spaciousness is excellent due to strong pickup of lateral
reflections.
*The out-of-phase impression of the surround pair disappears when a center coherent signal is added.
*The system is compatible in surround, stereo and mono. In other words, the surround signals do not
phase-interfere with the front-pair signals. That is because (1) the surround signals are delayed more
than 20 msec, (2) the two mic pairs operate in separate sound fields, and (3) the surround mics form a
bidirectional pattern in mono, with its null aiming at the sound source.
If a PZM wedge is not acceptable because of its size and weight, other arrays with wide stereo separation may be substituted. Some Crown mics well suited for orchestra miking in surround are the CM700 cardioid, CM-150 omni, SASS-P MKII stereo mic, and PZM-6D.
LETTERS FROM CROWN MIC USERS
Clear PCC-160s for hockey game miking
Editor’s note: In a recent article we told how PCCs are used to mike hockey games. The mics are
taped to the clear plexiglass barrier which protects the crowd from hockey pucks. The PCC base is
made of clear Lexan to make the mic less visible.
Clear PCCs: What a great idea! I have also used PCC’s when I worked as a freelance mixer for Fox,
and would like to expand on your idea. Why not remove the boundary altogether? When you affix the
PCC to the glass, the glass becomes the boundary. Also, color the PCC case/cable a light grey, and
you would not see it at all on TV.
Randy Meador, North Phoenix Baptist Church, Phoenix, AZ
Reply:
Thanks for the great idea, Randy. There is a consideration, however. Suppose you remove all of the
boundary plate except for the part that holds the mic capsule and circuit boards. Then the mic capsule will be raised about 1/8" from the nearest boundary, which is the plexiglass hockey-puck shield.
This spacing will cause some phase cancellation at high frequencies, which will roll off the highs a
little. However, this may not be a problem in practice.
Miking audience comments with an overhead PZM [This letter has been paraphrased slightly.]
We recently completed an installation using a Crown PZM-10 surveillance microphone for the council
chamber room for the City of Eagle. Eagle is a very nice, upscale town near Boise, Idaho that is
currently experiencing an economic boom. The council room already had a sound system consisting
of five Crown LM-300 microphones for the council members to use, and one dynamic microphone on
a floor stand for the citizens of Eagle to stand and be heard. The mixed signal was fed into the house
PA system as well as a recorder used for transcribing the meeting (Fig. 6).
Fig. 6. Council miking system.
However, the mayor and the council members were convinced that a few of the citizens were not
comfortable with standing at the microphone and airing their opinions. Some of them had been voicing their opinions from the seating area and not getting their opinions on tape. The City Council
wanted to make sure that all opinions were being recorded and taken into consideration.
To accommodate them, we suggested installing two PZM microphones on the ceiling over the seating
area. Being concerned with the appearance of the overhead microphones and the use of the citizen’s
money, they asked if they could get by with just one microphone. We installed one Crown PZM-10 in
the center of a 1/4" thick piece of 12" x 12" white acrylic (Fig. 7). Since the ceiling tile in the room is
also white and each square measures 12" x 12", the PZM-10 and its acrylic boundary would blend in
well.
Fig. 7. PZM-10 on a foot-square boundary isolated from the ceiling.
We thought that the PZM might pick up too much sound from the ceiling-mounted speakers, since the
microphone now had to be mounted in the center of the ceiling amongst the speakers. To compensate for the lack of coverage, we also felt that we would have to turn up the gain more than we did
with two microphones. To avoid those problems and the possibility of feedback, we installed a thin
layer of white rubber door seal around the upper edge of the acrylic boundary to insulate it from vibration before mounting it to the ceiling.
As stated before, the house mixer controls all the council mics. We sent the house mixer’s aux output
to another 4-channel mixer with phantom power. Then on the 4-channel mixer, we mixed in the PZMl0, and fed this mixer’s main output to the recorder (Fig. 6). This way, the PZM-l0 signal was not sent
to the house mixer which feeds the ceiling speakers. This worked out well since the city wanted to
record only the comments and opinions of the citizens.
The result was a very clear recording of all the citizens from their seats-even those who chose not to
speak into the stand-mounted mic in front. The city is very pleased with the performance and the
appearance of the installation. So are we. Thanks for making high-quality components and for making it easier for us to please our customers.
Robert S.(Rob) Manwill
QSI Systems, Inc.
###
MIC MEMO
Fall 1998
Bruce Bartlett, Editor
CM-700s ENHANCE BASSES IN UTAH SYMPHONY
CM-700
Allen Tucker, recording engineer for the Utah Symphony in Salt Lake City, prefers to use Crown CM700 cardioid condenser mics on the double basses. “I get very good definition and articulation compared to other mics,” says Tucker. “We tried the AKG 391 with a CK-1 capsule, which we were using
on strings and woodwinds. I liked the CM-700 much better on the basses.”
Tucker notes, “I’m really impressed with the mic, especially considering its price range. I wouldn’t
mind having a whole truckload of them.”
EAR CLIP HOLDS CM-10 LAVALIER MIC FOR THEATER USE
When you run sound for stage plays, you often must wire the actors with wireless mics. The Crown
CM-10/E miniature omni is ideal for this purpose. Where can you put the mic so that it is invisible, but
picks up well?
Try making the ear-loop clip shown in Figure 1. Find a loop that is used with some earphones. Such
earphones might be available from assistive-listening suppliers. Tape the mic cable to the loop, and
hook the loop over the ear. The mic becomes hidden in the hair at the temple. Even though the CM10/E is an omni mic, the gain before feedback and isolation are very good with this mounting.
The mic is invisible because it is hidden in the actor’s hair. The cable exits behind the ear, through
the hair, down to a belt-pack transmitter.
Fig. 1. Ear loop clip for CM-10 mini omni mic.
You may need to boost the highs because of the head’s shadowing effect on high frequencies. But
watch out for feedback.
To prevent sweat from reaching the microphone along its cable, wrap some sponge material around
the cable.
The source of this information was an article in the Alpha Sound & Lighting Co. catalog, supplied by
David Glass of Crown.
CUSTOMIZE YOUR PZM-185
Did you know that a piece of foam can act as an acoustic equalizer? You can modify the high-frequency response of a PZM-185 microphone by putting a piece of windscreen foam between the mic
capsule and the boundary “paddle.”
The PZM-185 normally has a peak in its response around 11 kHz to compensate for being off-axis to
the mouth in conference applications (Figure 2, solid line). But if you want the mic to have a flatter
response for music recording, you can change it.
Fig. 2. Effect of adding foam to PZM-185.
Find a foam windscreen, and cut out a piece about 1/8" thick and 3/8" square. Pry the boundary
paddle off the PZM. If you hold the PZM upside down, you’ll see the mic capsule near the front of the
mic. Lay the foam piece on the mic capsule and replace the paddle.
Now the PZM-185 will have a response something like the dashed line in Figure 2. To get the response shown in the dotted line, stack two pieces of foam.
NEW LM-201 LECTERN MIC IGNORES THUMPS
LM-201
Crown is happy to introduce the LM-201 lectern mic with internal shock mounting. The mic capsule
“floats” in a soft rubber suspension, which isolates it from mechanical vibrations such as thumps and
handling noise.
Featuring a new low-noise mic capsule, the LM-201 is intended for use on lecterns, pulpits, and similar applications. Its unique ball-and-socket swivel lets it be adjusted without any creaking — unlike
the old-style goosenecks. Swivel motion is limited to prevent cable damage.
The microphone is easily installed with wood screws or bolts. It is rugged, and is built to withstand
daily abuse.
Because of its supercardioid pickup pattern, the LM-201 rejects background noise and reverberation,
and improves gain-before-feedback, more than a cardioid mic.
The LM-201 has a smooth, wide-range frequency response for natural reproduction of the voice. Low
frequencies are filtered out to reduce pickup of lectern thumps, room rumble and breath pops.
The included wire-screen grille has an internal pop filter to reject explosive breath sounds. An external foam windscreen is supplied for extra pop filtering or for outdoor use.
CM-700 PERFECT FOR PIANO
The following note was posted on the Internet:
“Finally, I saw this on a concert broadcast on PBS and it sounded great. They had two small-diaphragm condensers (Crown CM-700, Neumann KM-84, etc.) in an X-Y patttern clamped in the center
of the frame. I have since used this technique a couple times with great results.”
-Bob L.
“I agree. I had great results with the jazz group ICU miking the piano with 2 Crown CM-700s. I don’t
see them on stages too often around here, I guess they’re just too inexpensive to make it on a rider... :
) “
-Michael Kivett
At the Elkhart Jazz Festival, your Mic Memo editor used two CM-700s on grand piano for P.A. The
mics were about 8 inches horizontally from the hammers and 8 inches above the soundboard, angled
down to aim at the hammers (Fig. 3). One mic was over the treble strut and one over the bass strut.
The lid was on the high stick.
Fig. 3. A piano miking technique.
Isolation from other instruments was good, and the tone quality was natural. A slight EQ cut at 250
Hz reduced the tubbiness from lid reflections.
PZM-10LL LINE LEVEL SECURITY MIC
PZM-10LL
Designed for security and surveillance, the new PZM-10LL features a line-level output. This Pressure
Zone Mic resembles a light switch so it disappears in use. Its tubular housing mounts in a hole in a
ceiling panel, wall or table.
The microphone has a balanced, line-level output from its “pigtail” 1-foot cable. Powering is by 12 to
24V DC.
In the PZM-10LL, low frequencies below the voice range are rolled off to reduce pickup of air-conditioning rumble. The high-frequency response is boosted to help articulation. Because of its tailored
response and PZM construction, the PZM-10LL picks up conversation or other desired sounds with
extra clarity and definition.
FOAM WINDSCREENS HAVE LITTLE EFFECT ON RESPONSE
When you put a foam pop filter or windscreen on a microphone, does the mic’s frequency response
change? Figure 4 shows the answer. In Figure 4 (top), adding a 2-inch diameter foam windscreen to
a Bruel & Kjaer lab mic has no effect under 10 kHz. The highs roll off about 1.5 dB at 20 kHz.
Fig. 4. Effect of foam windscreen on B&K mic (top) and CM-200A (bottom).
Figure 4 (bottom) shows how a foam pop filter affects a Crown CM-200A handheld mic. The response drops 1 dB from 6 kHz to 18 kHz.
So, while foam windscreens tend to attenuate the highs, the effect is not serious.
SILENT SWITCHING OF CM-311HS
Bill Cowgers, an audio engineer who works with remote TV trucks, came up with a clever way to
silently switch a CM-311HS to two destinations: to the producer, or to the on-air feed.
Each mic (without electronics) is connected to two CM-311HS circuit modules. To switch the mic from
on-air to producer, he mutes one circuit and unmutes the other. No switching pops.
EFFICIENT MIC CHANGES AT FESTIVALS
Mic changeover between acts
Many of you are doing sound reinforcement or recording at music festivals. A major part of these jobs
is changing the mic setup between acts. If this is not done right, the changeover can be slow and
confusing. One engineer I know ended up with a big ball of tangled mic cables by the end of the gig!
Here are some tips on changing the mic setup efficiently between acts.
If possible, have a production meeting at least a day before the gig. Invite all the mixers, stage crew,
and recording personnel. Make it clear who will serve as the head engineer, responsible for the final
say. Specify who will provide which equipment, who will handle mic changes, monitors, etc.
Ideally, obtain stage plots for the bands ahead of time. On these plots, write each mic’s placement
and model number. Give a copy of the plots to FOH, monitor mixer and stagehands.
Some engineers use an overhead projector backstage to project an acetate of the next band’s stage
plot. Aim a small video camera at the image and send the feed to FOH and the monitor mixer. There,
small video monitors show the setup.
Give the stagehands walkie talkies or wireless intercom headsets. At least use standard hand signals
so they can communicate with the FOH person. A single wired intercom is an option. But it may not
work as well because there is only one person on stage trying to relay the instructions.
Make sure each stagehand is responsible for a particular set of mics, unless you have a crew that is
used to working together.
Offstage, have a set array of mics on booms with coiled cables. You can pull them out when needed.
Keep some mini omni mics (lavaliers) offstage to use on acoustic guitars or fiddles.
Label each mic-cable connector with a number that corresponds to its input. Put the same number on
both ends of the cable. You might number the mics from left to right, and plug them in so the mic on
the left of the stage is on the left side of the console.
For mic assignments that won’t change from act to act, label the mic stands according to their instruments and/or channels.
Changing drum mics between acts is too time-consuming. Get one good drum kit, set it up properly
before the show, and make everyone use it. Drummers often bring their own cymbals and kick-drum
pedals, however. You might also have a single bass amp that all the bass players use.
Pre-set the drums and backline amps on a low and sturdy rolling riser or two so that the swap can go
faster.
When you can pick up an instrument direct, do so. The sound may not be as good as from a micro-
phone, but the setup is easier and leakage is eliminated. If you’re using hand signals to the stagehands, be sure you have a signal that means “flip the ground lift on the DI.”
Decide on the snake and console channel assignments ahead of time. Allow enough room on the
console to accommodate the largest group that will play that day (within reason). For example, if one
band has two bass inputs and one stereo guitar, and another has one bass and three mono guitars,
have enough channels for each without repatching: 2 bass and 3 guitar channels.
For an acoustic folk festival, you might try the following setup: Assign instrument mics to odd-numbered channels, and assign vocal mics to even-numbered channels. Keep the instrument and vocal
channels for each person next to each other on the console.
When the first band comes on, if you have no stage plot, ask them what instruments and vocals will
need mics. Take notes. Write up a channel-assignment list and place it next to the snake box. Contact the FOH person and read off the list, or write a second list and run it up to FOH. Place mics and
plug in cables according to the list.
Here’s a sample channel-assignment list:
1. Bass DI
2. Kick Crown PZM-30D
3. Snare Crown CM-200A
4. Rack tom CM-200A
5. Rack tom CM-200A
6. Floor tom CM-200A
7. Drums overhead left Crown CM-700
8. Drums overhead right Crown CM-700
9. Lead guitar CM-200A
10. Rhythm guitar CM-200A
11. Keyboard mix DI
12. Lead vocal CM-200A
13. Bass player vocal Crown CM-311A
14. Keyboard player vocal CM-311A
The FOH mixer should solo each input over headphones to make sure it is working and free of buzzes
and crackles.
Ask the band members where they want their monitor speakers to go. Also ask what they want to
hear in their monitors, and how many monitor mixes they need. Relay this information to FOH.
To keep the stage uncluttered, put out only as many mics as the band needs. Keep the rest in the
wings.
As soon as one act ends, the FOH mixer should turn down or mute the master faders and monitorsend faders. Pull all cables from the snake. Pull each mic/stand/coiled cable to the back or edge of
the stage. This keeps the stage clean and keeps the coils untangled. Don’t move mics from one
instrument to another: this can tangle the cables very quickly.
Some engineers prefer to leave the mic cables plugged into the snake. Between acts, unplug each
mic. Pull the mics/stands to the back or edge of the stage. Pull the cables back to the snake and coil
them neatly, side-by-side and in numerical order. While the next act is setting up, reset the mics
where they are needed and rerun the cables.
If you collect all the mics between each act, this helps you account for all the mics.
To sum up: Plan ahead, maintain communications, and clear the stage between acts.
Many thanks for these tips from the following sound people on the Internet: Glenn, Scott Dorsey,
Fletcher, Jon Best, Mark Donnelson, Shiva, Eric Handler, Michael Knowles, Scott Fraser, and Paul
Tumolo.
###
MIC MEMO
Winter, 1999
Bruce Bartlett, Editor
SOUNDMAN USES 22 CM-700 MICS
CM-700
“They’re great,” said Anthony Andorfer of D&L Communications. He’s a soundman for his local school
and church. “We started out with two CM-700s. We couldn’t believe they were so good, so we got
twenty more.”
Anthony uses the CM-700 cardioid condenser mics on everything: piano, acoustic guitar, flute, choir,
handbells, and so on. “It works really well on grand piano. I use three mics per piano.”
To pick up stage plays in the school gym, Anthony employs ten CM-700s on desk stands. The mics
are spread across the 70-foot stage. He sets each mic’s bass-tilt switch to “low-cut,” which filters out
rumble.
SASS RECORDS SOUND EFFECTS FOR PLAYSTATION GAME
The Crown SASS-P MKII was used to record realistic sound effects for NBA Shootout 98, a simulation/arcade basketball game for the PlayStation. The audio team’s goal was to create NBA-quality
sound to complement this popular title.
The recording process is described by Chuck Carr, a composer/sound designer/audio engineer at 989
Studios in San Diego, Calif. (formerly Sony Interactive Studios America).
“We used a Crown SASS-MKII microphone to record stereo/binaural sound effects... Binaural audio
works exceptionally well for ambient environmental sounds and one-shot sound effects.”
“We decided to rerecord the sound effects from SHOOTOUT 97 and add some incredible 3D stereo
samples into the mix, such as ambient room basketball bounces and shoe squeaks. We knew what
kinds of sounds we were looking to get before we started recording and discovered some great audio
nuggets such as shoe stomps, grunts, and springy basketball rims after istening to the finished recording.”
“We rented a local gymanasium for two hours to record our assistant producer and his brother playing
basketball.” The SASS recorded the big 3D sounds, like dribbling, shoe squeaks, rim hits, etc.
Source: Game Developer magazine, Sept. 1998.
“STOMP” PERCUSSION SHOW RELIES ON PCCs
PCC-160
The Broadway musical “Stomp” is a remarkable musical performance done in pantomine. All the
music is played with homemade percussion instruments: trash can lids, hubcaps, garbage bags,
plastic tubes, push brooms, and so on. It is a highly entertaining, original production.
To pick up the sound of all these instruments, sound engineer Jimmy Acecedo uses up to 30 mics
deployed all over the stage. His main mics are four Crown PCC-160s (supercardioid boundary mics).
Jimmy covers the mics with Saran Wrap to waterproof them from the water-bottle antics on stage.
Figure 1 shows the frequency response of a PCC-160 as is. Figure 2 is with limp Saran Wrap covering the mic. Figure 3 is with tight Saran Wrap.
Fig. 1. PCC-160 as is.
Fig. 2. PCC-160 covered by limp Saran Wrap.
Fig. 3. PCC-160 covered by tight Saran Wrap.
Limp Saran Wrap creates a 3 dB loss in the upper mids, and reduces the rear rejection between 200
Hz and 3 kHz. Tight Saran Wrap also creates a 3 dB loss in the upper mids, reduces the bass by 2
dB at 100 Hz, and gives much less rear rejection from 50 Hz to 6 kHz. Clearly, it’s better to leave the
Saran Wrap limp rather than stretched. The Wrap is more acoustically transparent when loose.
UNIQUE GLM PIANO-MIKING METHOD
Tom George, a sound engineer for 8th Day Sound, invented an unusual technique for miking grand
piano. It uses two GLM mics taped PZM-style to the underside of the raised lid.
Over the treble strings is a GLM-100 mini omni mic. Over the bass strings is a GLM-200 mini
hypercardioid mic. The front of each mic faces the piano lid. According to George, the GLM-200
gives a sound with more bass than the GLM-100.
TRY AN MB-4 FOR E.N.G.
MB-4 mini boundary mic
Want an easy way to mike a press conference? Try an MB-4 Mini Boundary Mic. It’s a tiny, rectangular, surface-mounted microphone. Just stick it on a table or lectern in front of the person speaking.
No messing with mic stands. Plug the mic into a DAT recorder with phantom power, hit record, and
there’s your news recording.
LETTERS FROM CROWN MIC USERS
SASS on CD
A concert I recorded using the SASS-P MKII has been released by Newport Classics. It is a program
of music by the American composer Charles Griffes and includes some premiere recordings.
I lent the recording to a friend. Upon hearing it, he immediately ordered the SASS-P MKII for himself!
Joe Stanko
New York City
###
MIC MEMO
Spring 1999
Bruce Bartlett, Editor
THIS MIC'S ALL WET
Crown is happy to introduce the PZM-11LLWR: a water-resistant Pressure Zone Microphone with a balanced, line-level output. A plastic membrane inside the microphone protects the mic capsule from water
damage. The mic mounts in a standard electrical outlet box.
Applications include fast-food restaurants, outdoor intercoms, toll booths, bridges, state park nature centers, theme park security, home automation, and so on.
The microphone can be plugged directly into a VCR line input -- no costly mic preamp is needed. Output
(via screw terminals) can be balanced or unbalanced. Powering is by 24V AC or 12-24V DC. The unit can
be factory-set for phantom powering by special order.
In the PZM-11LLWR, frequencies below the voice range are rolled off to reduce traffic rumble. The highfrequency response is boosted to help articulation. Because of its tailored response and PZM construction, the PZM-11LLWR will pick up conversations or other desired sounds with extra clarity.
The unit is "water resistant," which means:
*The microphone will work during and after rainfall.
*The mic's frequency response will change temporarily if the membrane gets wet, but will return to normal
when dry.
*If water freezes on the membrane, the mic's frequency response will change, but will return to normal
when the ice melts and the membrane dries.
*High-pressure water sprays directly on the membrane (through the louvered wall plate) may damage the
membrane.
*The microphone is not designed to be submerged.
Specifications
Transducer type: Electret condenser.
Frequency response (typical): 80 Hz to 10,000 Hz
Polar pattern: Hemispherical.
Equivalent noise level (self-noise): 26 dB SPL typical,
A-weighted.
S/N Ratio: 68 dB at 94 dB SPL.
Maximum SPL: 100 dB SPL produces 3% THD at maximum gain.
Operating temperature range: -10 to +60 deg. C, 14 to 140 deg. F.
The mic still works at -40 deg. C but its sensitivity is reduced.
When the mic is returned to normal operating temperature, its
sensitivity will be within +/- 3 dB of normal.
STEREO GUITAR MIKING SOUNDS SO REAL!
Doug Krehbiel, a recording engineer in Newton, Kansas, offers an effective method for miking an acoustic
guitar:
Start with two CM-200A mics (cardioid condensers) and mike the guitar in stereo. Realism is greatly
enhanced by stereo miking.
As shown in Figure 1, one CM-200A aims at the bottom of the bridge from 9 inches away. It is angled in
about 45 degrees and is about 25 inches from the floor. The second CM-200A is chin height. It aims at the
"sweet spot" where the neck joins the body, from 11 inches away. This mic is about 3 feet off the
floor and is angled in about 45 degrees.
Fig. 1. Suggested method for miking a guitar in stereo.
Doug says, "When I used this technique, the guitarist said, 'It sounds just like Nashville!'"
FISHING WEIGHT STRAIGHTENS CHOIR-MIC CABLE
Crown rep Daniel Casada relayed a dealer tip to us. When hanging a CM-30 or CM-31 choir mic, put a
6-ounce fishing weight on the cable. Attach the weight just behind the microphone.
This extra weight straightens the mic cable when the microphone hangs. It also angles the mic more
toward the choir.
Thanks to Crown's Mark Chapman for this information.
JANET JACKSON TOURS WITH CM-311 HEADWORN MIC
On her 1998 tour, superstar Janet Jackson used a Crown CM-311 headworn mic (now the CM-311A). It
was mounted on a custom boom which comes up under Janet's chin.
Since her show included so much dancing, a headworn mic was a must. FOH engineer Robert "Cubby"
Colby chose the CM-311 because, in his words, it's "The ONLY headset mic." Special tape was used to
hold the mic in place because Janet perspires from dancing.
We're proud that major performers like Janet Jackson and Garth Brooks prefer the Crown CM-311A.
Source: Dec. 1998 Pro Sound News.
PZM-11 WALL MIC IDEAL FOR HOME AUTOMATION
Imagine that you're sitting in your living room, and the room feels cold. You simply say, "Temperature: 70."
A mic picks up your voice and sends it to a sound card in your computer. Software recognizes your command. A controller tied to your computer turns on the furnace and sets the thermostat to 70
degrees.
This is an example of a home automation or voice-command system. It includes a microphone in each
room, a mic mixer, your computer, and a controller. A typical model is the Home-VoiceTM Multi-Room Kit
by applied Future Technologies, http://www.appliedfuture.com/MultiRoom.html.
Because the PZM-11 typically costs little and mounts easily in an electrical outlet box, it is ideal for such a
system. Other choices are the PZM-11LL (line level), PZM-10 and PZM-10LL.
CROWN SASS-P MKII STEREO MICROPHONE ENHANCES
JEWEL'S IN-EAR MONITOR MIX
A Crown SASS-P MkII stereo condenser microphone enhanced the in-ear monitor (IEM) mix for singersongwriter Jewel during a series of recent concert touring dates.
Eighth Day Sound, a touring company based in Cleveland, supplied the Crown SASS-P to Colm O'Reilly,
Jewel's long-time monitor engineer. With a unique, patented design based upon Crown's PZM Technology, the SASS-P provides precise and realistic sound that accurately conveys the ambient environment,
creating well-focused natural stereo imaging.
O'Reilly began utilizing the mic during Jewel performances on the Lilith Fair tour, clamping it to the front
lighting truss at the halfway point, about 10 feet downstage of her normal stage position. Pointed toward
the audience, the SASS-P captured crowd ambience, which was then blended into Jewel's stereo IEM mix.
"The SASS delivered impressive gain and a flat response," O'Reilly notes. "Rarely did we need to apply
any equalization, except in extreme acoustic environments, where the top end was rolled off a little bit."
Based upon this successful evaluation period during Lilith Fair, O'Reilly then employed the SASS-P
throughout a subsequent three-week tour. He adds that this approach stands in contrast to the typical
method employed for capturing crowd ambience, which involves placement of microphones at stage left
and right (either flown or on stands). These mics generally pick up only the chatting noise of the people in
the extreme nearfield, while at the same time, they tend to produce resonance not consistent with the
stage and venue.
"We were able to achieve very good response with this approach, based around the SASS. It sounded just
as if she were standing between two PA stacks in a normal concert situation, without the isolation of in-ear
monitors," O'Reilly explains. "Jewel just loved the sound and mix we were able to create."
Thanks to Crown's Bob Lichty for this information.
POOR MAN'S BASS TRAP
If you play an amplified bass guitar through a speaker in a room, and do a bass run up the scale, you may
hear some notes that boom out in the room. The room is resonating at those frequencies. These resonant
frequencies, which are strongest below 300 Hz, are called room modes or normal modes. They occur in
patterns called standing waves. Room modes can give a tubby or boomy coloration to musical instruments
and voices recorded in that room.
Mic techniques can help. Here's how. Standing waves are patterns of sound-pressure buildup in the
room. At certain points in the studio, the resonances are strong; at other points, there are nulls: areas
where the resonances are weak. You can use this fact to your advantage. When recording a vocal, move
the mic around to find a null spot where the sound is not boomy. Record the vocal there.
PHANTOM POWER AND BIAS VOLTAGE: IS THERE A DIFFERENCE?
The following article was submitted by Mike Petterson from Shure Brothers. Thanks, Mike!
Many users of professional audio equipment believe there is no difference between phantom power and
bias voltage. Not true! Phantom and bias are not interchangeable. This article explains the differences
between phantom and bias, and addresses common misconceptions.
Phantom power (Figure 2) is a dc voltage (11-48 volts) which powers the preamplifier of a condenser
microphone. Phantom power is normally supplied by the microphone mixer, but may also be supplied by a
separate phantom power supply. Phantom requires a balanced circuit in which XLR pins 2 and 3 carry the
same dc voltage relative to pin 1. So if a mixer supplies 48 volts of phantom, XLR pins 2 and 3 of the
microphone cable each carry 48 volts dc relative to pin 1. Of course,the mic cable carries the audio signal
as well as the phantom voltage.
Figure 2. Phantom power.
Mixers that supply phantom power contain current-limiting resistors which act as control valves. If the
microphone or cable is improperly wired, these resistors limit the flow of current to the microphone and
thereby prevent damage to the phantom-supply circuit.
A balanced dynamic microphone is not affected by phantom power. However, an unbalanced dynamic
microphone will be affected. Although the microphone will probably not be damaged, it will not work properly.
Bias (Figure 3) is a dc voltage (1.5-9 volts typically ) that is provided on a single conductor. Unlike phantom power, bias does not require a balanced circuit. Bias supplies power to a Junction Field Effect Transistor (JFET) connected to the output of an electret condenser mic element. The JFET acts as an
impedance converter which is a necessity in any microphone design that uses a condenser element. A
condenser element has a high output impedance (>1,000,000 ohms). The JFET input loads the output of
the condenser element with an even higher impedance (>10,000,000 ohms) to minimize loss of signal
level. Also, the JFET output provides a low source impedance (<1,000 ohms) to feed the microphone
preamplifier.
Figure 3. Bias applied to a microphone capsule.
In some condenser microphones, the bias voltage must be supplied on the same conductor as the audio.
Condenser elements with a built in JFET use this configuration and employ a single-conductor shielded
cable. Other condenser microphones utilize separate conductors for bias and for audio. Consult the manufacturer's data sheet to find out the exact wiring configuration.
A dynamic microphone should not be connected to an input that supplies bias voltage (such as a wireless
transmitter) because the audio and the bias voltage will travel down the same conductor. If this occurs, the
frequency response of the microphone may be altered or the audio signal distorted. If a dynamic microphone must to be connected to an input with bias voltage, a blocking capacitor must be used. The blocking capacitor is placed in series with the hot conductor of the microphone. The capacitor passes the audio
that is present on the hot conductor while blocking the dc bias voltage. The capacitor must have enough
capacitance to pass the audio signal without degradation. The exact value depends upon the electronic
characteristics of the microphone circuit and must be calculated for each situation.
Remember, in a typical electret condenser microphone, it is the JFET that requires unbalanced bias and
the preamplifier that requires balanced phantom power. Therefore, a condenser microphone that requires
phantom power will not work with an input that only supplies bias, e.g. a wireless transmitter.
Once again....phantom and bias are not interchangeable!
###
®
Crown’s Quarterly Microphone Newsletter Bruce Bartlett, Editor
Summer 1999
The Perfect Mic For Mobile DJ's: CM-311A Pro Audio/Video
Recording On A
Budget
When you're the hottest mobile entertainer act in the
country, you don't settle for
less than the best when it
comes to the sound of your
performance.
That's why Los Angeles based
and three-time Female Entertainer of the Year, Lisa
Capitaneli, won't trust her
shows to anyone but Crown.
We quote Lisa from her web
page, http://
www.dothedance.com/
crownad.jpg:
"The CM-311 is by far the best
headset microphone around. I'm able to move around the dance floor and in front of the speakers with no fear of feedback. In
my opinion, it is one of the best contributions a manufacturer has ever given to the DJ industry."
Lisa has won the American Disc Jockey Awards Female Entertainer of the Year, 1996, '97, '98; and is creator of the hot new
dances "Do the Dance" and "Joy."
Riverdance Relies On SASS Stereo Mic
In the blockbuster musical/dance show, Riverdance, the Crown SASS-P MKII stereo mic was used to pick up a wide array of
percussion instruments.
Gary Pillon using a SASS-PMKII stereo mic with a camcorder.
Gary Pillon, GTN's 29-year veteran location soundmixer,
loves to share his enthusiasm for exciting new audio products in the columns he writes for Michigan VUE magazine.
Here are some of his comments from the Jan/Feb '99 issue:
"Speaking of ambience, the Crown SASS-P MKII is still the
best microphone under $1000 for getting "panoramic
According to an article by soundmixer Chris Kathman in July '98 Pro Sound News, "The percussion setup should be in a sculpture museum; it has gigantic, dramatically sweeping cage elements, with only a few mics: an SM57, and SM81, a 421 and an
unorthodox Crown SASS-P stereo overhead. There are other lavs for instruments and Samson foot mics for the dancers."
Continued on page 2
Featured Inside
MB-4 mic for voice recognition
■ Differoid mic featured on Jackson’s
album cover
■ Crown announces matched stereo
mic pairs
■ Wiring Crown mics to wireless
micrtransmitters
■ How to hang a SASS mic
■ Crown PZMs make huge drum
sound
■
Mic Memo
Continued from page 1
SASS as a counterbalance on the bottom of the Steady
TRACKER hand-held platform, and used the VP88 as a
audio-only feed to a TASCAM DA-P1 DAT recorder. The
Crown tracks were a perfect match to the XL1's field of
view..."
audio vistas." If your production needs more focused dialog pick-up, then the mid-side Shure VP88 is the microphone of choice in that price range.
"Mount the Shure on a Mighty Wondercam Rover with a
quick release plate, put the SASS-P on the sled base of a
GLIDECAM V-8, and the Canon XL1 will let you record both
perspectives for thousands less than the price of a comparable Sanken, Neumann, Schoeps, or Soundfield system...
Neither the Shure or Crown microphones suffered unduly
from wind or handling noise... I've been going to the State
Fair since I was five years old, and I've got to tell you, these
recordings (four different perspectives using the shure and
SASS models) sounded right. Each microphone offered a
valid, useful and compelling point-of-view.
From the Mar/Apr 1999 issue of Michigan VUE:
"I've been making Crown PZM stereo recordings from these
camera platforms for close to 15 years. In the last two
years, full bandwidth, stereo surround, ambience extraction
devices from Lexicon, Circle Surround, and Meridian have
made it possible to print the signal as 5.1 'discrete' electrical channels of information. In its new form, it can be released on DVD or broadcast on DTV as a 5.1-channel mix
without needing a separate ambience decoder box in each
viewer's home." The Dolby Digital or DTS decoder already
used for playing your disc collection will be able to handle
these extracted/encoded tracks.
"I decided to tape the Renaissance Festival at Canon's
higher quality two-channel audio settings. I mounted the
Gary Pillon (left) and Bryan Varga (right) capturing sounds at the
Renaissance Festival.
Try An MB-4 Mic For Voice Recognition
Seeking a good mic for computer voice recognition, sound
consultant Mark Curry tried a variety of mics. Some were
headworn, others were boundary mics. Curry had a disabled client who issued voice commands from his wheelchair and needed his computer to respond.
To Curry's surprise, a PCC-170SW worked with 100% accuracy on voice recognition from across the room! Even with
music playing in the background, the client could speak
commands several feet from the PCC-170SW (on the computer desk), and the computer would understand the commands.
Curry asked us if there were a less expensive alternative to
the PCC-170SW. We recommended the MB-4E, which is a
supercardioid boundary mic like the PCC-170SW. But the
MB-4 costs only $109 (suggested list), and is much smaller
than the PCC-170SW.
Either mic picks up speech reliably at a distance. By using
them, you may not need a headworn mic to talk to your
computer!
Differoid Mic Featured
On Jackson’s Album
Cover
On the cover of superstar Janet Jackson's new album, "The
Velvet Rope Tour Live in Concert," Janet is wearing the
Crown CM-311A Differoid headworn mic. The microphone
has become part of her look on stage.
In the cover photo, the rear of the mic is shielded with a
foam windscreen.
Jackson's album is a spectacular concert filmed live at
Madison Square Garden, New York. It was released on DVD,
VHS and Laserdisc.
Mic Memo
Crown Announces Matched Stereo Mic Pairs
Crown will be offering pro recording microphones in stereo
matched pairs. One pair, CM-700MP, is two CM-700 cardioid condenser mics. Another pair, CM-150MP, is two CM150 omni condenser mics. The microphones will be
matched in sensitivity and frequency response within 1.5
dB.
Pairs of the CM-700 or CM-150 work great for stereo recording a classical music ensemble, folk group, drum set,
piano, vocals, percussion, and so on.
Because of its pre-aged titanium diaphragm, the CM-150
omni is extremely stable over a wide range of environmental conditions.
Several audiophile touches enhance the CM-700's pristine
sound quality: an ultralight diaphragm, humbucking transformer, polycarbonate capacitors, and a gold-plated 3-pin
connector.
Both models have a very smooth, wide-range frequency
response which gives them a natural sound. They preserve
the delicate timbre of acoustic instruments, yet can reproduce all the power of a pipe organ. The off-axis response is
also smooth.
Self-noise is very low, permitting clean, noise-free recordings. The mics can handle very loud sounds without distortion. Protection against static and RFI is included. The
output is balanced, low impedance, which allows long cable
runs without hum pickup or high-frequency loss. Powering
is by 12-48V phantom power.
CM-700 frequency response is 30 Hz to 18 kHz (50 Hz to 16
kHz +/- 2.5 dB); self-noise is 21 dBA. CM-150 frequency
response is 20 Hz to 20 kHz +/- 1.5 dB; self-noise is 19
dBA.
In the data sheet for the CM-700 cardioid matched pair, we
offer the following advice about stereo mic techniques:
Coincident pair (XY):This technique is mono-compatible.
Angle the mics inward so their grilles are aligned vertically,
and angle them 90 degrees to 135 degrees apart. An angle
of 90 degrees gives a narrow stereo spread unless the musical ensemble surrounds the mics in a semicircle. An angle
of 135 degrees gives a wider stereo spread, but may have
some off-axis coloration.
Near-coincident pair: Angle the mics outward and space
their grilles a few inches apart horizontally. In the O.R.T.F.
stereo mic technique, the mics are angled 110 degrees
apart (55 degrees either side of center) and are spaced 17
cm (7 inches) apart. This technique tends to provide accurate localization and sharp imaging. Another technique is
the N.O.S. method: angle the mics 90 degrees apart and
space the grilles 1 foot apart. This method has less off-axis
coloration than the O.R.T.F. method but less-sharp imaging.
Angle the mics down slightly so they will aim at the musical ensemble when raised. Raise the mic pair on a boom
stand (typically about 14 feet high for an orchestra). Place
the mic stand about 5 to 20 feet from the front row of
musicians. Find a miking distance where you monitor the
desired amount of hall ambience. Close miking sounds
close; distant miking sounds distant.
A suggested equalization is +3 dB at 80 Hz, - 2 dB at 5 kHz
and +2 dB at 12 kHz. This EQ compensates for distant
miking and off-axis placement.
In the data sheet for the CM-150 omni matched pair, this
advice is given about stereo miking:
Place each CM-150 on a separate mic stand, or place both
mics on a stereo mic mount of your choice that allows up to
1 meter of spacing.
The wider the spacing betwen microphones, the wider the
stereo spread. A spacing that tends to give accurate localization is about 2 feet. Smaller spacings tend to have a
narrow stereo spread; wider spacings tend to have exaggerated separation of off-center instruments. If you hear excessive movement of a centrally placed soloist, place the
mics closer together. A spacing of 12 feet tends to pick up a
good balance of a symphonic band or orchestra. Mixing in
a third CM-150 placed between the outer pair will improve
the localization.
Angle the mics down slightly so they will aim at the musical ensemble when raised. Raise the mic pair on a boom
stand (typically about 14 feet high for an orchestra). Place
the mic stand(s) about 4 to 15 feet from the front row of
musicians. Find a miking distance where you monitor the
desired amount of hall ambience. Close miking sounds
close; distant miking sounds distant.
Mic Memo
Wiring Crown Mics To Wireless Mic
Transmitters
How To Hang A SASS
Mic
Below is a list of some popular transmitter models, followed by the connector to use with each one, and its wiring to various
Crown mics.
David Stas of CES Corp. told us a clever way to hang a Crown
SASS stereo mic over a musical ensemble. Hang the mic
from two mic cables, each with a right-angle XLR connector plugged into the SASS. Attach the other end of the
cables to a grid or other stucture near the ceiling.
In this list, the Hirose 4-pin connector is the Hirose HR10-7P-6S.
CM-10/E
Audio-Technica Hirose 4-pin 1 & 2: shield & black, 3: yellow, 4: 4.7K to pin 3
Electro-Voice Switchcraft TA4F 1: 2.2K to pin 3, 3: yellow, 4: shield and black
Before hanging the mic, first you need to determine a good
mic position. Put the SASS on a tall mic stand and make
test recordings. Once you find the sweet spot, hang the
SASS there.
Nady Switchcraft TA3F 1: shield and black, 2: 2.2K to pin 3, 3: yellow
Samson most models Hirose 4-pin 1: 2.2K to pin 2, 2: yellow, 6: shield & black
Samson ST-2 Hard-wired. 1 & 2: shield & black, 3: 2.2K to pin 4, 4: yellow
Samson CT-3 Hard-wired. 1: 2.2K to pin 2, 2: yellow, 3 & 4: shield and black
Shure Switchcraft TA4F 1: shield and black, 2: 2.2K to pin 3, 3: yellow, 4: jumper to pin 3
Telex Switchcraft TA4F or Lemo 4-pin 1: shield and black, 2: yellow, 4: 2.2K to pin 2
Crown PZMs Make
Huge Drum Sound
GLM-100/E
Audio-Technica Hirose 4-pin 1 & 2: shield, 3: white, 4: red
Electro-Voice Switchcraft TA4F 1: red, 3: white, 4: shield
Nady Switchcraft TA3F 1: shield, 2: red, 3: white
Samson most models Hirose 4-pin 1: red, 2: white, 6: shield
Samson ST-2 Hard-wired. 1 & 2: shield, 3: red, 4: white
Samson CT-3 Hard-wired. 1: red, 2: white, 3 & 4: shield
Shure Switchcraft TA4F 1: shield, 2: red, 3 & 4: white
Telex Switchcraft TA4F or Lemo 4-pin 1: shield, 2: white, 4: red
In recording the third album for British "gothic trip hop"
duo Switchblade Symphony, engineer Gregory Butler found
a great use for PZMs. The album was recorded in an large
unfinished room in a house by the ocean in Malibu, California.
Nady Switchcraft TA3F 1: shield, 2: red, 3: white
"For the drums... we knew that trying to mic it like a normal
drum kit would be usless in that room. So we thought,
'Let's make a really huge drum sound then.' We hung
Crown PZMs from the ceiling and put mics five feet off, ten
feet off, behind the kit... just to try and get the room. And
the drums ended up sounding bigger than Led Zeppelin."
Samson most models Hirose 4-pin 1: red, 4: white, 6: shield
Source: "Tracking in the Wild" by Alan Di Perna, Feb. '99 EQ.
CM-311A/E and CM-312A/E
Audio-Technica Hirose 4-pin 1 & 2: shield, 3: white, 4: red
Electro-Voice Switchcraft TA4F 1: red, 3: white, 4: shield. 470 pF cap. bet. pins 3 and 4
Samson UT-5 Hirose 4-pin 1: red, 2: white, 6: shield
Shure Switchcraft TA4F 1: shield, 2: red, 3: white, 4: jumper to pin 3
Telex Switchcraft TA4F or Lemo 4-pin 1: shield, 2: white, 4: red
Crown’s Quarterly Microphone Newsletter Bruce Bartlett, Editor
Fall 1999
How To Blow Up Speakers
Community Loudspeakers puts out a document called “Recommended CD’s for Demo Use.” It is a
list of CD’s that they “successfully used for demos which will bring out the best qualities of good
loudspeaker systems (or point out the faults in poor quality speakers).”
One such CD is the Crown SASS Demo Disc:
Track 37 Fireworks
Track 40 Harley-Davidson Motorcyle
Track 42 Jets Takeoff
Community says, “Play these three tracks of sound effects real loud and you’ll blow up almost any
competitive loudspeaker system. Of course, Community loudspeakers have the PowerSense[tm]
protection circuitry in the crossovers, so they will survive the ordeal.”
The SASS demo CD has been discontinued, but the fireworks and motorcycle tracks can be found on
the Crown Microphone Demo CD, which is currently available. If you’d like a copy please send $4.95
for shipping and handling to Literature Dept., Crown International, 1718 W. Mishawaka Rd., Elkhart,
IN 46517.
Crown Headworn Mic Enhances Sarah Brightman Concert
Sarah Brightman, a skilled and compelling soprano, performed an exciting concert
named “One Night in Eden,” broadcast on PBS June 13. According to PBS, the concert “takes viewers to musical paradise, exploring a diverse range of musical styles,
from Titanic and the Bee Gees to Puccini...”
During the concert, Sarah sang through a Crown CM-311A Differoid headworn mic.
It was mounted a few inches in front of her mouth, rather than touching her lips.
This made the CM-311A act like a conventional stand-mounted mic, with a more
natural sound free of breath pops. It also kept the mic out of the singer’s face. Feedback
was not a problem in this
application, so the distant
Featured Inside
placement worked well.
How to blow up speakers
■ Crown headworn mic enhances
Sarah Brightman concert
■ Serafine says SASS is fine
■ CM-700 rave review
■ Now available: The Mic Memo
CD ROM
■
Sarah Brightman From http://www.sarah-brightman.com/video01.html
Sarah starred in the Andrew
Lloyd Webber musicals Cats,
Requiem, and Phantom of
the Opera; and recorded
several top-selling hits such
as “Who Wants to Live Forever” and “Time to Say
Goodbye.”
Mic Memo
Serafine Says SASS Is Fine
We heard you’re using the SASS-P for
motion picture work?
Oh, frogs in Florida, trains, crickets, playgrounds,
school ambience... lots of things like that.
Oh yes, I am. I use it for recording ambiences. The mics are very sensitive and pick
up sounds for miles. The ambiences they
pick up are really nice.
Are you running into any hiss or noise
problems with it?
Both indoors and outdoors?
SASS-P MKII
Hollywood film-sound designer Frank Serafine
had some good things to say about his recent use
of the Crown SASS-P stereo microphone. We
spoke with him recently about his work.
No, not really.
Do you have to EQ the signal?
Yeah, anything I want super high resolution
to. It’s an overall really good mic for out in
the field, or for big dynamic sounds.
No, I don’t do much of that either. I try to get the
best sound I can on the spot. The positioning or
the way I mike things has a lot to do with the way
the sound is used.
Are you using the original SASS-P?
We appreciate your time, Frank.
Yeah, I’ve had it for about 15 years.
No problem!
What are some typical ambiences you
might record?
CM-700 Rave Review
“[The CM-700’s] sound so great... My choice for
overhead and acoustic guitar was SM-81s. I
couldn’t believe my ears... I’m blown away... I’m
shocked... I’m floored... I’m amazed... Excellent
mic... Way underpriced. I’m sold.”
“Did more tracking today with them. I may get a
Neumann KM184 for a day just to compare. These
Rowan published the following review of the CM700 on ProRec (reprinted with permission). The
web site is at http://www.prorec.com.
I was fortunate to receive a matched pair of
Crown CM-700s for review almost two months
ago. I have spent the better part of those months
making extensive use of these microphones, and I
Copyright 1999 by Rip Rowan
CM-700
Here are some email quotes from Rip Rowan,
Editor of the on-line recording magazine, ProRec:
Pro and Home Recording Resources on the
Internet:
Rip Rowan
sound better than any small
diaphragm condenser I’ve
ever used. Wonderful! Fantastic! Clear highs, never
brittle, nice rise about 6K,
smooth, not metallic. Better
hands down than an SM81,
which is a compliment.”
am happy to report that we have a serious morefor-less contender in these mics.
Crown has produced the CM-700 for some time
now, but only recently began shipping these as
matched pairs. The matched set includes a stereo
mic mount for X-Y applications. Retail for the pair
is about $580, and can be found on the street for
less than $450.
Mic Memo
Just the Facts
The Crown CM-700 is a single pattern cardioid
condenser microphone. The operative word in any
description of this mic is flexibility. Crown has
designed the CM-700 to serve virtually any application where a cardioid microphone would be
suggested.
Two bass rolloffs are provided: a low-cut setting
provides a gentle slope below 110 Hz, while a
rolloff setting gives more bass-reduction with a steep cut below 110
Hz. I thought these were misnamed.
The cut provides a gentle rolloff, and
the rolloff provides a sharp cut. [Both
switch positions have a gentle rolloff,
but the “rolloff” setting starts at a
higher frequency — Ed.]
The mic features a humbucking transformer probably the primary reason the mic is less sensitive and slightly more noisy than other competitors. However, I’m a big fan of good-sounding
transformers. I think that mics with good transformers often have a sweeter top end and a
rounder bass response than many of the
transformerless designs available.
have a pretty powerful proximity effect, which
was borne out in testing.
My CM-700MP shipped with the optional CMSM shockmounts. These simple but elegant
Crown was generous enough to ship the CM700s on the first day of a week-long set of sessions cutting rhythm tracks for an
upcoming release by Four Mile Mule,
a popular Dallas roots-rock/country
band. I immediately popped the mics
up over the drums as overheads and
started dialing in sounds — probably the most typical application for
this mic. Actually, I found this to be
the best-sounding drum miking kit
I’ve ever used: SM-57 and Marshall
MXL-2001 on snare, AT-Pro25 on
kick, SM-81 on hats, AT-4050s on
toms, and the CM-700 MPs as
overheads. We achieved some remarkably fat and tight drum sounds
that day.
Specifications suggest a fairly
middle-of-the-road mic. Self-noise
(21 dB SPL, A-weighted) and signal-to-noise ratio (73 dB) put these
mics generally below audiophile
mics from Neumann, Schoeps and
Earthworks. The mics also display
CM-700MP matched pair
[relatively] low-level sensitivity at
-52 dB re 1 mW/Pa. These specs would suggest
shockmounts will fit many different condenser
that this is not going to be the mic of choice for
mics. I found them to be a good fit for my SM-81s.
very quiet applications such as quiet acoustic
These little shockmounts are very cool, and proguitar picking or other sensitive field recording
vide a wireclip to hold the wire and keep the mic
applications. On the other hand, the mic can sussuspended properly in the shockmount.
tain 151 dB, unpadded, so it is easy to envision
The mics are quite small, the smallest cardioid
that this mic will be very useful for many rock,
condensers I own — about the size of
jazz, and country music applications such as
Neumann’s KM184. This makes it easy to get the
drums, guitar cabinets, vocals, and other intense
mic into tight spaces. Also I noticed that the conapplications. [I’ve used the CM-700 on quiet
denser element is right up against the protective
acoustic guitar with no noise problems, but your
wire mesh - you can get that element within a
results may differ — Ed.]
couple of millimeters of the sound source! And
Frequency response indicates a relatively
with its high maximum SPL, you don’t have to be
agressive mic. The response rolls off slightly below
afraid to just get the mic right up there against
50 Hz, and a couple of treble bumps [2.5 dB —
the drum or speaker. Of course, with an element
Ed.] at 6 kHz and 10 kHz suggest a mic with a
so exposed I imagined this microphone would
sharp top end and a relaxed bass performance.
Crown also ships a windscreens with the mic. It’s
the usual “afro” looking egg-shaped screen found
with many mics. [A hoop-type pop filter is recommended for vocal recording -- Ed.]
Studio Testing
As I have gone forward into mixing the drums, I
find myself usually starting with the drum
overheads full-up, and dialing in the close-miked
drums to add a little beef. This is in sharp contrast
to other mic kits I have used on drums — I have
previously used my matched AT-4050s as
overheads, and their agressive sound tends to
make cymbals too harsh to put forward in the
mix. These CM-700s have an agression too —
but the treble boost is shifted up an octave above
the 4 kHz boost of the 4050s. Cymbals have a
clear and bright sound — and as I suspected, the
humbucking transformers provide a smoothness
in the cymbals that my transformerless AT4050s
cannot provide. These are sweet-sounding mics!
So, these mics first application as drum overheads
passed with flying colors.
Mic Memo
Next came acoustic guitar. I reached for my SM81 — usually the mic of first choice when recording an acoustic. We got a good sound, and I
was tempted to just run with it. Then we threw up
the CM-700s, and I was really surprised at what I
heard. The CM-700s actually sounded better —
and, dare I say, more accurate than the SM-81. I
think that what I was hearing was the diminished
treble response at 4 kHz and the accentuated
response at 6-10 kHz, because the SM-81s are
clearly flatter than the CM-700s. However, the
CM-700 sounded less harsh and more “fluffy”
than the SM-81. The guitar sounded smoother,
rounder, less harsh. We recorded acoustic guitars
for the project largely with the CM-700s, backed
up with the SM-81 for quiet parts as well as my
trademark “mystery mic” secret weapon for lo-fi
sounds. For quiet acoustic guitar, you want a more
sensitive microphone, but for strong rhythm parts,
the CM-700 is outstanding.
We also used the CM-700 on electric amps with
mixed results. I am just not a fan of using condenser mics on guitar amps. The key exception to
that is the AT-4050, which is an OUTSTANDING
mic on any guitar amp. The applications where
the CM-700 worked well were room miking of
the guitar amp, where you really want to hear the
sound of the room. These are applications better
suited to omni mics anyway. One nice thing about
using the CM-700 in a room is that it seems to
exhibit a gentler cardioid rolloff than my other
cardioid mics — it’s less “pinched” and more
“open”.I think this mic could also be excellent at
recording that full-range Marshall distortion
sound that’s popular now in heavy guitar music,
but we didn’t have an opportunity to try this mic
on an application like that. This could also be a
great bass amp microphone. Unfortunately we
didn’t have the opportunity to try that either.
Finally, we tried the mic on vocals. Now, I’m a big
believer in the use of large-diaphragm
condenders on vocals, so I was a little skeptical of
an inexpensive small-diaphragm condenser on
vocals. But, I’d be a fool not to try it.
I was really surprised how good this mic sounds
on vocals. I guess I shouldn’t be: the mics nice,
smooth treble boost at 10K is typical of the great
vocal mics like the C-12 and U47. The CM-700
isn’t as warm as those tube mics - it lacks the
complexity and richness in the midbass and low
midrange (300-500 Hz) of these large-diaphragm tube models - and it is fairly bassy. The
effect is slightly “scooped out” with a nice, bright,
smooth treble. I was right about the proximity
effect. This mic’s proximity effect can really add a
lot of bass! And with that diaphragm way up
front you must be VERY careful with plosive consonants. A poorly-delivered “P” can really wreck
your day. For that reason I would recommend
using a good pop filter at all times, and keeping
the singer from singing “right down the tube”. For
an intimate vocal sound, the CM-700 can really
put the singer right in your lap.
Conclusions
In the end I was very pleased and amazed at the
sound of these mics. Specifications only tell part
of the story. No numbers had prepared me to hear
the truly beautiful sounds that this mic is capable
of producing. From percussion to guitars to bass to
vocals, this mic is a strong contender in virtually
any application, particularly close miking of loud,
powerful sounds. Before buying any other smalldiaphragm condensers, you really need to listen to
these mics. The CM-700s are a strong contender
— and they have earned a permanent place in
my studio.
Now Available: The Mic Memo CD-ROM
mation on Crown microphones. The issues are
arranged in chronological order. Whatever your
application, you should be able to find useful tips
here.
PZM pioneer Ken Wahrenbrock was the first editor
of the PZM Memo, which later became the Crown
Mic Memo as Crown developed a full line of microphones.
Now in stock at Crown is the Mic Memo CD-ROM.
It features twenty years of Mic Memo issues — a
tremendous database of applications and infor-
To search for a particular topic in this document,
you can use Windows’ FIND function. Type
<CTRL> F and enter the word or words you are
searching for.
Want to know more about stereo applications?
Do a search for “stereo”. Repeat until you find all
the places that the word “stereo” was mentioned.
Are you interested in applications for the GLM100? Search for “GLM” or “GLM-100.” All the app
notes for this microphone will appear, one at a
time.
This document, “20 Years of the Crown Mic
Memo,” is also on the Crown web site at http://
www.crownaudio.com . Click on “Microphones,”
then click on “Info & How To.” We hope you find
the compilation an invaluble tool.
®
Crown’s Quarterly Microphone Newsletter Bruce Bartlett, Editor
Winter 2000
SASS® Makes Demo Recording Easy
Sometimes, making a demo recording can be
done in a matter of hours instead of weeks.
Mark Darnell, a Crown microphone technician,
came up with a nifty way of recording his jazz
combo. He arranged the band in a basement
room, and miked them all with a SASS-P MKII
stereo mic (Fig. 1). The mic was raised on a boom
stand about 1 foot below the ceiling.
Since there was no mixing involved, Mark moved
the instruments toward or away from the SASS to
adjust their balance and stereo position. After a
few trial recordings, he wound up with a realistic,
honest demo tape of the band’s performance.
This method may not work well with all types of
bands. It would be hard to record a rock band like
this and still get a good balance and a tight sound.
But if you have a small acoustic jazz group you’d
like to record, the SASS just might work for you.
Fig. 1
Britney Spears Relies On Crown
CM-311AE
Photo from Cute magazine by Frank White
Featured Inside
SASS® makes demo recording easy
■ Britney Spears relies on Crown CM-311AE
■ PZM panel helps pick up choir
Garth is in good company. The October
1999 issue of (wow) Cute magazine fea■ Theater sound-master describes PCC-160
tures several photos of pop