Royer | SF-2 | User guide | royer SF-2 User guide

Royer Labs
Model SF-12
Stereo Ribbon Velocity Microphone
Operation Instructions Manual
& User Guide
Made in U.S.A.
Model SF-12 Ribbon Microphone
Revised 2015
User Guide
Using the SF-12 Ribbon Microphone
Amplification Considerations
Stereo Microphones and Ground Loops
Equalization and Ribbon Microphones
Hum, Noise and Mic Orientation
Microphone Techniques
General Tips for Using the Royer SF-12
Specialized Stereo Recording Techniques
Classic Blumlein Technique
Mid-Side (M-S) Technique
Care and Maintenance
Care for the Optical Black Finish
Wiring Diagram
Polar Pattern
Frequency Response
Congratulations on your purchase of a Royer Labs model SF-12 ribbon microphone. The SF-12
is a handcrafted, precision instrument capable of delivering superior sound quality and overall
high performance.
This operator’s manual describes the SF-12, its function and method of use. It also describes the
care and maintenance required to ensure proper operation and long service life. The users guide
section of this manual offers practical information that is designed to maximize the performance
capabilities of this microphone.
Royer Labs products are manufactured to the highest industrial standards using only the finest
materials obtainable. Your model SF-12 went through extensive quality control checks before
leaving the factory. Normal care is all that is required to assure a lifetime of trouble-free service.
Please read this manual thoroughly in order to become familiar with all of the SF-12’s
capabilities. It will assist you in making the most of its superior acoustic properties. This owner’s
manual is a handy reference guide and we suggest you refer to it whenever questions arise on the
use and care of your SF-12 ribbon microphone.
The SF-12 is a compact, stereophonic ribbon microphone array consisting of two matched
microphone elements that are placed one above the other. Each transducer is positioned at 45¼
to the left and right of center, or 90¼ from each other. When held vertically, connector down and
the “ROYER” logo facing the sound source, the upper microphone is the right channel and the
lower one is the left channel, from the perspective of an observer behind the mic. The
microphone elements are each bi-directional (figure-8) and may be addressed from either side
with equal sensitivity. The in-phase signals are achieved when the microphone is addressed from
the front, as indicated by the “ROYER” logo. If, however, the microphone is suspended upside
down, the connections to the preamplifier should be reversed since what was the left transducer
is now responding to signals from the right and vice versa.
Your SF-12 is equipped with a 5-pin XLR extension cable and a splitter cable that fans out to
twin 3-pin male XLR connectors. As shipped from the factory, the connectors are marked
“upper” and “lower” since referring to them as “left” and “right” could lead to confusion.
The SF-12 is reasonably tolerant of shock and vibration, but care should be taken to prevent
accidental stretching of the ribbon elements. This is covered in the Care & Maintenance section
of this manual. The performance of the microphone is unaffected by changes in temperature or
User Guide
Using the SF-12 Ribbon Microphone
The SF-12 is a versatile device capable of accurate sound reproduction. There are a few
important facts about ribbon microphones that are key in understanding how to use them
1. The SF-12 is a side-address, bi-directional microphone and the rejection in the ‘dead’ areas is
very strong. Due to this directionality, ribbon microphones should be placed at 1.3 times the
distance normally used with omni-directional microphones, or about the same distance used
for cardioid microphones. This method is used to achieve the same ratio of direct to reflected
2. In the horizontal plane, ribbon microphones do not discriminate against the ‘highs’ off axis,
nor do they boost them on axis. Therefore, several instruments or vocalists can be placed in
front of the microphone without favoring the performer in the center of the group.
Several performers can be grouped at both the front and the back of the microphone, with
one proviso; since the outputs are out of phase at the front and back of the microphone,
cancellation can result if two tenors are placed on opposite sides at equal distances and are
singing in unison. Therefore, listen to the feed before committing to it.
3. The Royer model SF-12 requires no power supply and is safe to use on consoles with
phantom microphone powering, provided that the cabling is wired properly. It should be
noted that not all ribbon microphones are compatible with phantom-powering systems, so
check the manufacturer’s recommendations before using other ribbon microphones. Faulty
or improperly wired cables could also cause problems with your SF-12.
4. Never attempt to test the SF-12 or any ribbon microphone with an ohmmeter. A blown ribbon
could result.
5. Always provide adequate protection for your SF-12, or any ribbon microphone for that
matter. If the microphone is to remain set up on a stand when not in use, place the included
mic sock over it until it is to be used. Do not carry the microphone around without placing a
mic sock over it. Failure to follow this common-sense practice may yield a stretched ribbon
and compromised performance!
Amplification Considerations
The performance of a ribbon microphone is directly affected by the choice of microphone
preamplifier it is paired with. With so many mic preamps on the market, how do you select one
that gives the best possible performance with a ribbon microphone? Additionally, what kind of
performance can we expect from the preamplifiers built into our mixing desks? While most
preamplifiers will handle ribbon microphones well in most recording situations, some preamps
that work perfectly well with condenser or dynamic mics may prove to be poor performers with
To begin with, we must understand the fundamental differences between ribbon microphones and
other popular types, namely condenser and moving coil dynamics. A ribbon microphone is
actually a dynamic microphone that uses a flat, extremely low mass ribbon element, rather than a
coil/diaphragm assembly. For this writing, any mention of “dynamic” microphones will relate to
moving coil dynamics.
All condenser microphones have a built in preamplifier called a head amp and therefore put out a
hefty signal. Because the signal is buffered through the head amp, the output impedance is rather
low and less affected by the input impedance of the microphone preamp. Most dynamic (moving
coil) microphones generate a healthy enough electrical current to work well with a variety of
preamps, and their limited frequency response characteristics make mic loading less of a
Ribbon microphones generate a highly accurate signal, but the average ribbon mic generates
approximately 20dB less gain than that of condenser microphones. Remember, the ribbon
transducer does not have the benefit of a condenser mic’s built in head amp, so a ribbon
microphone relies solely on the microphone preamp for all its gain!
The so called ideal preamplifier is the proverbial “straight wire with gain.” This may be
considered the technological ideal and does not include “coloration” as a desirable feature.
However, coloration is often desirable and has given rise to the popularity of certain preamps and
even preamp stages in mixing desks. Neve® preamps and the famous Trident® A Range mixing
console are highly praised for their classic sound.
So what should we use with our beloved ribbon microphones?
The features that translate into top performance for a ribbon microphone are the following:
1. Lots of gain! A ribbon microphone works best with preamplifiers that have at least 60-70 dB
of maximum gain.
2. Low noise is a must! With this much gain being required for efficient operation of a ribbon
microphone, the noise characteristics of the preamp play a pivotal role in overall performance
of the captured acoustic event.
3. Load characteristics: A suitable preamplifier should have input characteristics that impose the
least amount of loading to the ribbon element. In other words, the input impedance should be
high enough that its effect on the performance of the mic is negligible. A good rule of thumb
is to have a preamplifier with input impedance at least five times the impedance of the
microphone. For example, if the mic is rated at 300 Ohms (as Royer’s are), the preamp
should have an input-impedance of at least 1500 Ohms. If the impedance of the preamp is
too low, the microphone will lose low end and body.
4. Transparency: A good preamp should sound natural with no edginess. Tube preamps sound
warm, yet wonderfully transparent. Transformer coupled preamps sound punchy. When
recording with condenser or dynamic microphones, engineers often choose mic preamps that
help warm up the mic, but warming up the signal does not need to be a consideration with
ribbon mics because they are by nature warm and realistic sounding.
Stereo Microphones and Ground Loops
Some preamplifiers are prone to developing ground loops when used in conjunction with stereo
or multi channeled microphones such as the SF-12. Ground loops can develop in the preamplifier
with any stereo microphone, regardless of the type (i.e. condenser, dynamic, ribbon). A ground
loop manifests itself as unwanted buzz or hum at 60 Hz and/or harmonics of 60 Hz.
The condition is brought on when the left and right transducer elements are plugged into two
inputs of a stereo or multi-channel preamplifier. The two three-pin male XLR connectors on the
SF-12’s splitter cable share Pin-1 as ground, so they are grounded to each other through the cable
set. If the grounding scheme within the preamplifier is poorly designed, or the distances to
internal ground are too great, a ground loop develops. The problem may be more apparent with
ribbon microphones because of the high gain required for proper operation.
You can perform a simple test to check for this condition (preferably done with a pair of
headphones to avoid feedback). Plug one side of the stereo microphone into either preamplifier
input. Listen to the output of the preamp. All should be quiet except for the mic signal. Now plug
the second side into the next preamplifier input. If a noise or buzz develops, you have a ground
loop. The ground loop may be very slight or more pronounced, depending on the preamp.
Battery powered preamps usually do not exhibit this problem, and neither do well designed, line
operated mic preamps. The simple fix is to disconnect one of the microphone’s two Pin-1 ground
connections. A better method is to make a small ground lifter out of a male-female XLR barrel
adapter. Switchcraft makes a very nice one and it takes less than five minutes to wire it up.
Simply connect Pin-2 to Pin-2, Pin-3 to Pin-3, and leave Pin-1 disconnected. Correcting the
problem at the preamplifier would be preferable, but is often more difficult and/or expensive. In
conclusion, try to find the best preamp you can afford that has good gain characteristics and low
noise. Coloration is optional.
Equalization and Ribbon Microphones
One of the great strengths of ribbon microphones is how well they take EQ. Even with
substantial amounts of equalization, ribbons retain their natural, “real” quality. For example,
when a lead vocal is being performed on a ribbon microphone, you can actually boost the upper
end frequencies to the point where the ribbon mic emulates the performance curve of a
condenser mic with excellent results. This is not to say that a ribbon microphone can replace a
quality condenser mic, but the EQ friendliness inherent in ribbon microphones does allow for an
enormous amount of flexibility.
The reason that ribbon mics take EQ so well is their inherent low self-noise, unusually smooth
frequency response characteristics and freedom from off-axis coloration. Dialing in high
amounts of equalization on condenser or dynamic microphones also means dialing in extra
amounts of the microphone’s distortion products and self noise contributing to an unnatural,
unpleasant sound. Because distortion and self-noise are almost non-existent in ribbon
microphones, high levels of EQ can be used without adding harshness or excessive noise.
Hum, Noise and Mic Orientation
All dynamic microphones, including ribbons, are susceptible to picking up stray alternating
magnetic fields. Power transformers (such as those found in guitar amplifiers) and alternating
current motors are the most likely sources of hum. Building wiring and electrical utility
transformers are other likely sources. A well-designed microphone provides shielding to
minimize the effects of stray magnetic radiation. In some cases complete isolation is impossible
and the result is usually hum or buzz. Ribbon microphones can potentially manifest this
condition to a greater degree because of their higher gain requirements. With vintage ribbon
microphones that employ large, bulky magnet structures, the problem can be worse. Royer SF-1
and SF-12 microphones are designed to minimize the effects of unwanted radiation by
integrating the transducer barrel as part of the magnetic return circuit. With this design, the
barrel that houses the transducer serves to complete the North-South magnetic return and
neutralizes the effects of outside magnetic radiation. The SF-1 mono and SF-12 stereo ribbon
microphones go one step further by incorporating toroid impedance matching transformers,
which have a natural ability to repel magnetic radiation.
Dynamic and ribbon microphones are passive devices, meaning they incorporate no external or
internal power supplies and have no head amplifier and therefore cannot produce hum on their
own. Unwanted noise (hum and buzz) can only come from an external source. Repositioning a
dynamic or ribbon microphone is the easiest way to identify and eliminate unwanted noise. If
hum is detected, it means that the microphone is in the proximity of an alternating magnetic field.
While listening (preferably with headphones) to the mic, move it around. The mic will find the
noise source quite easily. If you are miking a guitar amplifier and suspect the amplifier’s power
transformer may be the source of unwanted noise, move the mic around the amp. You will
probably find that the noise is louder as you approach the amplifier’s power supply and quieter
when you move it away. Eliminating the noise can be fairly simple and requires using the ‘null’
point of the microphone. The null point is the position where the microphone’s pick-up of stray
magnetic radiation is at its lowest. Slightly rotating the microphone is usually all that is required
to cancel out the noise. This is similar to the procedure guitarists use to eliminate noise from
single coil guitar pickups. There will be a position where the noise is greatly reduced or
disappears completely.
Microphone Techniques
General Tips for Using the Royer SF-12
The following are good basic starting places for recording with the SF-12. These positions are
known to produce good results, but experimentation is the key to getting the most out of your
recordings! Photographs of many of the following techniques can be found on our website,
It is important to remember that the SF-12’s ribbon elements can be damaged by wind. When the
SF-12 is mounted on a boom stand, be sure the stand is moved slowly. When the microphone is
taken down, put it in its box immediately or, if it is to remain in its shock mount, place the mic
sock over the ribbon end of the microphone. Leaving the microphone out unprotected is inviting
a re-ribbon.
Ensemble Performances
The SF-12 records ensemble performances beautifully. Simply find the point in the room where
you hear the best blend of the instruments and room sound and place the microphone there, with
its logo facing the performers.
For stereo recordings of stringed instruments, start by positioning the microphone a few feet off
the body of the instrument. Depending on the acoustics of the room, you may want to move the
microphone closer to or further from the instrument to add or minimize ambience. For violin,
position the SF-24 horizontally, two or more feet above the instrument. For larger string sections,
try placing the microphone slightly above the instrumentalists and angled down; a distance of
three or four feet will do the job nicely.
Drum Overhead & Room
Position the SF-12 horizontally over the center point of the kit, two to three feet above the
cymbals. For a centered snare drum, aim the Royer logo at the snare. Adjusting the height of the
SF-12 by even 6-inch increments will produce dramatic variations in how the cymbals sit with
the rest of the kit. Many times an overhead SF-12 is all that is
needed for tom-toms and cymbals.
For a single point stereo room mic, position the SF-12 vertically at
four to eight feet in front of the kit. Compress to taste for either a
very natural drum sound (light compression) or large rock drum
sound (heavy compression).
For jazz recordings, EQ is generally not required. For more
aggressive drum tracks where cymbals need to sizzle, you can
brighten them by adding a few dB of 10K to 12K.
Brass records beautifully with ribbon microphones. For an overall picture of a brass section
within a larger recording session, try placing the microphone two to three feet above the
instrumentalists and angled down, at a distance of three to eight feet from the section. For a solo
trumpet, position the SF-12 vertically at a height of four to eight feet and anywhere from five to
20 or more feet from the section.
Close miking brass is a job for the Royer R-121, R-122, or R-122V - we do not recommend
close-miking with the SF-12.
Reed Instruments
Normal working distances are about a foot or two from a solo reed instrument. For multiple
instruments, try placing the microphone slightly above the instrumentalists and angled down, at a
distance of two to four feet.
There are several positions that will give excellent results with the piano. Start with a distance of
one foot to several feet from the bend of the piano. A more direct, up front sound will be
achieved when the microphone is placed closer to the soundboard. If it is possible to remove the
piano lid, an SF-12 suspended horizontally over the soundboard will give outstanding results. If
the room sounds good, try positioning the mic 10 to 20 feet from the piano for more room
If you position the SF-12 under the open lid of the piano, there will be some amount of reflected
sound from the lid. Careful positioning can minimize or accentuate lid reflections, depending on
what sound you’re striving for.
Choir and Orchestra
An SF-12 can produce dramatically good recordings of an orchestra or choir. If possible, position
the SF-12 at approximately ten feet high and a few feet behind the conductor. The wide stereo
pickup will reproduce the orchestra or choir with a stunning you-are-there realism. The rear lobes
of the figure-8 elements bring the ambient qualities of the recording environment into the
recording, adding to the natural feel of the recorded performance.
The SF-12 records percussion instruments naturally, without upper frequency hype or low-end
boominess. Congas, bongos and the like can be recorded with left/right stereo effect by
positioning the mic within a few feet of the instruments. Shakers, bells, triangles and other
instruments that are often problematic in the upper frequencies will record naturally and nonabrasively.
Vocal with Acoustic Guitar
For recording a vocal with acoustic guitar, two separate mono tracks
are required with little leakage between the tracks. One stand and one
SF-12 can do the job nicely when the two axes of sensitivity are
correctly oriented (see illustration).
The SF-12 is not recommended for close-miking loud amplified
instruments. Its sensitive ribbon elements were not designed for
extremely high SPL applications like close-miked electric guitar. For
close-miking high SPL sound sources, ruggedness is a must and we
recommend using our R-121, R-122, or R-122V ribbon microphones.
Specialized Stereo Recording Techniques
Classic Blumlein Technique
For many years, “coincident” microphone setups have been widely used for picking up sounds in
stereo as naturally as possible. The “Blumlein” technique, named for A.D. Blumlein, involves the
use of two figure-eight microphones positioned as in
the sketch (see Figure 1); one mic faces left and the
other faces right, at an angle of 90¼ (i.e., each
displaced 45¼ from center).
Each microphone ultimately feeds one speaker in a
stereo system and, due to the directionality of the
microphones, the result is a very well defined stereo
image on playback. For classical music particularly,
the reproduction can be very satisfying.
Figure 1
The SF-12 stereo microphone is two identical ribbon
microphones in just this Blumlein orientation: if the
microphone is placed in front of the performance,
with the Royer logo facing the center of the ensemble
to be recorded, the microphone will give a stereo
recording as per the Blumlein technique. Because of
the togetherness of the SF-12’s ribbon transducers,
sound will arrive at both ribbon elements at the same
time. This means that the two channels can be summed to mono with no comb filter effects, and
room reverberation (undesirable in mono) is cancelled to a surprising degree.
For the sake of clarity, engineers commonly refer to similar stereo miking with cardioid mics as
“X-Y.” When figure-8’s are used, it is more commonly referred to as “Blumlein” recording.
Mid-Side (M-S) Technique
In the early days of stereo radio broadcasting, the Mid-Side recording technique was developed
to allow for 1) simultaneous stereo and mono feeds
from the same mic array and 2) electronic
manipulation of the width of the stereo image. In
M-S recording, one mic faces sideways, one faces
forward as shown in Figure 2, and they are
connected as shown in Figure 3.
With the SF-12's logo facing the center of the
performance, the mic is positioned for X-Y
recording. Rotating the SF-12 counter-clockwise
by 45¼ positions it for M-S recording.
Figure 2
With the SF-12 in a vertical position, cable end
down, the upper ribbon element faces the center of
the performance and is the ‘mid’ microphone, and
the lower ribbon element is at 90¼ to the
performance and is the ‘side’ microphone. If the
microphone is to be mounted upside down, make
the proper adjustments in your wiring orientation.
If the outputs of the mid and side elements are made equal using gain controls, the stereo pickup
will be similar to that of two microphones placed as a Blumlein X-Y pair, delivering a wide
stereo image. As you reduce the level of the side element, the width of the stereo image will
narrow until, with the side element turned all the way down, you have just the “mid” element
panned center and giving a mono pickup.
If the outputs of the mid and side elements are recorded on separate tracks, the electrical
connections shown in Figure 3 can be made at the mixer outputs and the adjustment of the stereo
separation can be done during mixdown, rather than during the actual recording.
Space does not permit a fuller discussion of the M-S intensity stereo format, first described by
Alan D. Blumlein over 50 years ago. We suggest the following reading on the subject:
W. Dooley & R. Streicher
“M-S Stereo: A Powerful Technique for Working in Stereo”
J. Audio Eng. Soc., Vol. 30 pp.707 (1982 Oct.)
Figure 3
Care and Maintenance
The SF-12 is a solidly built, precision instrument. All that is required to ensure proper operation
of this microphone is to follow some commonsense rules.
1. To avoid transducer damage, do not expose the microphone to severe shock or vibration. If
the microphone is accidentally dropped, test it to see if damage has occurred before returning
it to service. Low output or a dull sound would indicate a stretched ribbon.
2. Do not expose the microphone to direct blasts of air or strong air currents. Use a windscreen
or suitable blast filter when close miking a vocalist or certain types of wind instruments. Ppopping does not necessarily damage the ribbon element but may produce unacceptable
preamplifier overload and could cause damage to speaker systems.
3. Do not expose the microphone to liquids or caustic smoke.
4. Do not expose the microphone to strong alternating electromagnetic fields, i.e. the power
transformers in amplifiers, or a hum may result.
5. Use a soft cloth to clean the microphone body. A small amount of denatured alcohol can be
used to remove fingerprints and other stains.
6. Keep metal filings away from the microphone at all times. The SF-12's powerful magnets can
attract minute ferris particles into the ribbon transducers, compromising the performance.
7. When not in use, store the microphone in its protective carrying case. If the microphone is to
remain set up on a mic stand between sessions, cover it with its mic sock (provided with your
8. Leave disassembly of the microphone to a trained technician. There are no user-serviceable
parts inside.
Caution: Do not check the SF-12 with an ohmmeter or continuity tester, and do not connect the
unit to an input device designed to power a capacitor microphone. Strong winds and mechanical
shocks should be avoided.
Care for the Optical Black Finish
The SF-12's optical black finish is a sophisticated surface treatment designed to refract light
rather than reflect it. This makes the microphone appear less conspicuous, especially when used
with high intensity lighting or within a camera shot. The finish requires occasional maintenance
to retain a smooth, even appearance and to maintain its unique optical qualities.
The SF12's body is comprised of a low carbon steel alloy. Its finish consists of black chrome
deposited over a nickel substrate, creating a finish that minimizes the reflective nature of the
metal surface. A small amount of oil has been worked into the finish at the factory to protect it.
Over time, some of this oil will be drawn out due to "wicking" action; the physical handling of
the microphone, absorbent materials it is exposed to (like the foam padding of the microphone
case), etc. As the oils are drawn out of the microscopic surface layer, the microphone finish may
develop an uneven appearance. If this happens, simply massage the microphone gently with a
lint free cloth treated with a few drops of light machine oil or WD-40¨ (apply the oil to the cloth,
not to the microphone). Be very careful whenever working around the transducers to avoid
contamination of the ribbon elements. Following this simple procedure will protect the finish and
renew it to its original luster.
Due to the transducer’s powerful magnets, keep recorded tapes, spring-wound watches and
personal credit cards with magnetic coding away from the microphone to prevent possible
Wide, Smooth Frequency Range
Closely Matched Characteristics
Negligible Off-Axis Coloration
Excellent Separation and Imaging
True Figure-8 Polar Patterns
X-Y or M-S Recording
Acoustic Operating Principle:
Electrodynamic pressure gradient
Polar Pattern:
Symmetrical Figure-8
Generating Element:
Two 1.8 micron aluminum ribbons
Frequency Response:
30 Hz - 15000 Hz ±3 dB
> -52 dBv Re.1v/pa
Output Impedance:
300 Ohms @ 1 kHz
Recommended Load Impedance: > 1500 Ohms
Maximum SPL:
> 130 dB
Output Connector:
male XLR 5 pin (stereo)
206 mm L x 25mm W (8” L x 1” W)
369 grams (13 oz.)
Matte Black Chrome, Dull Satin Nickel (optional)
Protective wood case, one (1) 18’ shielded 5 conductor
cable with 5-pin connectors, adaptor cable terminating in
two (2) XLR type 3-pin male connectors, mic clip, mic
Optional Accessories:
Shock mount, WS-12 blast filter
To learn more about Royer products and their usage, visit our website at
Wiring Diagram
Polar Pattern
Frequency Response
Royer Labs hereby warrants all Royer SF-series microphones with the following terms and conditions.
Body fit and finish
Transducer frames/magnets
Vacuum Tube
Cables & Cable Sets
Shock Mount Accessories
Ribbon Element
10 years Parts and Labor
2 years Parts and Labor
2 years Parts and Labor
1 year Parts and Labor
From the date of original purchase and for the respective periods specified above, Royer Labs agrees to
repair, at its sole expense, all Royer Labs products which are defective in material and workmanship.
This warranty does not cover the following:
Defects or damage caused by accident, fire, flood, lightning or other acts of nature.
Defects or damage caused by abuse, misuse, negligence or failure to observe the instructions
contained in the owner’s manual furnished at the time of original purchase.
Damage caused during shipping or handling.
Products that have had their serial numbers altered or removed.
Products purchased in “AS-IS” (used) condition.
Products that have been altered or repaired by anyone other than a factory authorized service station.
2711 Empire Ave.
Burbank, California 91504
Telephone 818.847.0121
Fax 818.847.0122
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