microphones surveyed reviewed
MICROPHONES
SURVEYED
AND
REVIEWED
New from Cadac
Stereo Portable Console
Standard configurations available: 10/2 or 10/4 expandable to
20/2, 2Oí4.
10/2, 10/4 available ex -stock; other configurations are
available on short delivery times, 2-6 weeks.
Mic line inputs -Two Echo Sends -Two Foldbacks-PFL-Monitoring
-Five Frequency Oscilator, Comprehensive Talkback.
Equalisation divided into 5 bands covering 10 frequenciescurves:- reciprocal shelving and bell networks.
High quality accurately matched linear faders.
Fully balanced throughout.
Performance specifications to Cadac's usual high standards.
Telex, 'phone or write for complete technical information and
prices.
cuduc
The leaders in music recording consoles
and techniques.
Cadac (London) Ltd.
141, Lower Luton Road Harpenden Herts. AL5 5EL
Harpenden (STD 05827) 64351 Telex 826323
studio sound
AND BROADCAST ENGINEERING
EDITOR MICHAEL THORNE
JANUARY 1975 VOLUME
ASSISTANT EDITOR FRANK OGDEN
EDITORIAL PRODUCTION DRUSILLA DALRYMPLE
ADVERTISEMENT MANAGER RICHARD WESTBROOK
MAGAZINE SALES MANAGER DON BAILEY
ITHE LINK HOUSE GROUP
Editorial and Advertising Offices: LINK HOUSE, DINGWALL
AVENUE, CROYDON CR9 2TA. Telephone: 01-686 2599
© Link House Publications
Ltd 1974.
All rights reserved.
CONTENTS
FEATU RES
THE RIGHT MIC FOR THE JOB
By Angus McKenzie
28
SURVEY: MICROPHONES
32
THE CONTINUING STORY OF ILR-RADIO MANCHESTER
By Adrian Hope
54
COLUMNS
NEWS
LETTERS
36
PATENTS
CLEANFEED
AGONY
42
58
46
72
REVIEWS
NEUMANN U87i
By Angus McKenzie and Tony Faulkner
AKG C414
By Angus McKenzie and Tony Faulkner
SCHOEPS CMT36 AND CMT56
By Angus McKenzie and Tony Faulkner
AKG CK9
By John Fisher
SENNHEISER MKH 815T
By John Fisher
48
49
52
60
68
SUBSCRIPTIONS
STUDIO SOUND, published monthly, enables engineers and studio
management to keep abreast of new technical and commercial
developments in electronic communication. The journal is available
without charge to all persons actively engaged in the sound recording,
broadcasting and cinematographic industries. it is also circulated by paid
subscription to manufacturing companies and individuals interested
in these industries. Annual subscription rates are £3 (UK)
or £3.30 overseas.
CORRESPONDENCE AND ARTICLES
All STUDIO SOUND correspondence should
be sent to the address
printed on this page. Technical queries should be concise and must
include a stamped addressed envelope. Matters relating to more than one
department should occupy separate sheets of paper or delay will occur
in replying.
BINDERS
Loose-leaf binders for annual volumes of STUDIO SOUND are
available from Modern Bookbinders, Chadwick Street, Blackburn, Lancashire.
Price is £1.25 (UK and overseas). Please quote the volume number or date
when ordering.
17 NUMBER
1
POSSIBLY THE MOST useful equipment reviews are those of
power amplifiers. Since the requirements are fairly well-defined,
something vague about a straight wire with gain and a little selfinductance, it's a relatively simple matter to see how far a brushed
aluminium black box goes towards realising such a goal. And
then to pass judgement.
Again, small -signal modules have quite specific aims, within
some overall scheme. Again, argument centres on the relative
weight of mutually opposed parameters, such as noise and
distortion, and which compromise is more satisfactory. Nevertheless, different methods of achieving an end do not concern
the practical balance engineer; he is simply concerned that a
required performance is maintained.
Difficulties creep in when more than two black boxes are
involved, because they can be arranged in different ways.
Disagreement follows. Some people always want to do things
differently, which is unfortunate since it prevents attitudes sitting
comfortably still. Since all possibilities could only be catered
for by some sort of permutation -review, it's necessary to
generalise. Too bad if anyone objects to the application to him.
Microphones are a problem. Like music and other irrelevant
things, subjective effects remain uncodified and any discussion
can only be sustained by a good vocabulary and a certain
familiarity. And, in common with arts criticism, a pungent,
eloquent smoke screen is often more effective than careful, sincere
comment.
The most tiresome comments on mics and their use come from
the purists. But we must distinguish between the theoretician
(who, contrary to popular belief, stands or falls by the success
of his propositions and cannot be confounded by 'the practical
man' if he has done his sums right) and the witless plagiarist
(who either has only two mics anyway or has trouble in hearing
all he is supposed to through less than 18, even with pfl).
Naturally, a little arrogance goes a long way.
Crossed pair taking issue with multimic, and vice versa, is an
ultimately unrewarding spectacle; and the extreme polarisation
that used to characterise such arguments seems to have softened.
But the virtue of such debate was in providing points of reference
in the fog of practical technique, which acknowledges no basic
principles unless they lead to good results in a specific situation.
It isn't helped by some record critics who ought to know better
churning on about the `natural' balances and `coincident'
technique. Fortunately, such misprint is contradicted by anything
non -classical (music, not technique) rather more easily than the
also obvious confrontation with a mixer containing more than
two parallel lines of tone controls, balance controls, loudness
filters and other confusing little coloured buttons. But the bland
assumptions of true and false which underline such comments
are far-reaching. And if the artistic goal is open to facile dispute,
what chance the medium of doing its practical work right?
Next month, survey and reviews of straight wires.
STUDIO SOUND is published on the 14th of the preceding month
unless that date falls on a Sunday, when it appears on the Saturday.
A
III)
MEMBER O! THE AUDIT
SURFAU OF CIRCULATIONS
Total average net circulation
during 1973.
of 7,641 per issue
105. High Street
Eton. Bucks. SL4 6AF
Phone Windsor 51403
4
STUDIO SOUND, JANUARY
1975
ITA MIXERS
ITA, 10-4 MODULAR MIXER
countries
throughout the world
Now in use in
IS
Ten inputs.
4
output
groups.
4 limiters.
Base, mid,
treble EQ.
Balanced
inputs.
Modular
construction.
Headphone
monitoring.
£590
+
VAT
IMMEDIATE DELIVERY
NEW
FROM ITA
An expanded
version of the
ubiquitous 1014
modular mixer
with 20 inputs.
£930+vAT
NOTE NEW ADDRESS-TAIndustrial Tape Applications
5 Pratt Street,London NW1 OAE.Tel: 01-485 6162 Telex: 21879
5
1HE TPA IOO D IS 1HE MOST ADNkNCED
200W POWER AMPLIFIER MADE IN EUROPE
Most professional recording and broadcasting
studios in the U.K. use TPA series amplifiers.
CLIENTS USING TPA SERIES AMPLIFIERS INCLUD
ATV Network Ltd Thames T.V. Ltd I.T.N. Ltd RCA Ltd
Electricity Research Council Ministry of Technology
Cavendish Laboratory British Scientific Instrument Research Centre.
Radio & T.V.
De Lane Lea Processes Ltd
HH ELECTRONIC MILTON CAMBRIDGE
TEL 0223 65945
future pr of
With its all -modular construction
and plug-in pre -equalised head
blocks your Stellavox recorder
need never be obsolete.
Any current or future tape standard or format can be accommodated by simple exchange of
units, without taking the recorder
out of service.
Available in stereo, mono, with or
without pilot track, or quadraphonic.
Illustrated: SM7 Stellamaster,
music mastering recorder.
A.V. Distributors (London) Ltd.
Park Road, Baker Street,
London N W1 4SH.
26
Tel.:
01-935 8161.
Please send me further Stellavox
details.
Name
Address
SS/I/75
6
STUDIO SOUND, JANUARY
1975
What you ree
ii what you get.
The extraordinary Shure SM7 professional microphone features something
you've never seen before: a built-in Visual Indication Response Tailoring
System that offers you four different frequency response curves-and shows
you the curve you've selected with a graphic readout (see above) at the backof the microphone! Choose: 1. flat response; 2. bass roll -off; 3. presence
boost; 4. combination of roll -off and presence. And there's more: the SM7
delivers exceptional noise isolation with a revolutionary pneumatic suspension mount ... an ultra-wide, ultra -smooth frequency response ... an integral
"pop" and wind filter ... and a cardioid pickup pattern that looks "text -book
perfect." The Shure SM7 Studio Microphone was extensively field-tested in
recording studios and broadcasting stations! Write:
Shure Electronics Limited
Eccleston Road, Maidstone ME15 6AU
Telephone: Maidstone (0622) 59881
1111
51---IVRE
7
i
TANNOY
*
NEIN
HIGH PERFORMANCE DUAL
INCREASED POWER HANDLING CAPACITY
*GIRDACOUSTIC
*TANOPLAS SURROUND
*HIGH
TEMPERATURE VOICE COILS
CONE FOR SMOOTHER RESPONSE (3lomm
*IMPROVED
and
4lomm
models only}
FOR HIGH STABILITY AND LOW BASS RESONANCE
AND UP -RATED CROSS -OVER NETWORK
--
-:vam
15
F
2000e
TYPICAL RESPONSE 260 mm HIGH PERFORMANCE DUAL
I
TYPICAL RESPONSE 310 mm HIGH PERFORMANCE DUAL
0"I
Power Handling Capacity
Frequency Response
Intermodulation Products
(
2")
260 mm
10"
310 mm
410mm
50W
60W
85W
12'
15'
27-20,000 HZ 25-20,000 HZ 23-20,000 HZ
less than 2%
less than 2%
less than 2%
HIGH POWER
CONE WITH HIGH TEMPERATURE
GIRDACOUSTIC
VOICE COIL AND TANOPLAS
Impedance via
Crossover network
SURROUND
000
20
8 ohms
8 ohms
(5 ohms min.) (5 ohms min.)
8 ohms
(5 ohms min.)
*INTEGRATED PROGRAMME MATERIAL
TYPICAL RESPONSE 410 mm HIGH PERFORMANCE DUAL (15")
\+\ TANNOY
ALL SPECIFICATIONS SUBJECT TO ALTERATION WITHOUT NOTICE
NORWOOD RD. WEST NORWOOD. SE 27. 01-6701131
A COMPLETE LINE OF
TRANSFORMER BOXES FOR
RECORDING & SOUND
REIN FORCEMENT
AVAILABLE FROM SESCOM.
dbx
Noise .eduction Systems
MASTER
ROOM
Reverberation Units
MODEL: SM -1
"Split -Matcher" Studio -Box
for electric guitar's to plug into
sound systems.
MODEL: MS -1
"Microphone Splitter" plug mic
into box and get two isolated
outputs. Only 1Y2 db insertion
loss.
MODEL: MS-2 (Not Shown)
"Microphone Combiner" plugs two mics into box and gets common
output.
(Send For Complete Catalog)
AENGUS
Mixing Console Modules
and other products
for Professional Audio
QUALITY ENGINEERED SOUND PRODUCTS
SESCOM, INC.
P. O. Box 4155, Inglewood, CA 90309 USA
Telphone (213) 678-4841
8
STUDIO SOUND, JANUARY
1975
Scenic Sounds Equipment
27-31 Bryanston Street. London W H 7AB
1
Telephone 01-935 0141
BX2D
STUDIO REVERBERATION UNIT.
Anglia Television
Angus McKenzie Esq.
ATV
Audio International Sound Studios
BBC
BRMB Birmingham
Capital Radio
Catholic Radio and TV Centre
Chipping Norton Recording Studios
Churches Television and Radio Centre
Decca Records
De Wolfe
Echo Studios
Eddy Offord
EMI Studios
Escape Studios Kent
Fairview Music
Goosberry Studios London
Granada Television
Helios Electronics
Hillside Sound Studios
HTV
Indigo Sound Studios Manchester
John Kongos Studios London
Kay Laboratories
Kingsway Recorders
Marconi
Maritime Studios
Olympic Sound Studios
Pinewood Studios
Polydor Records
PYE Records
Radio Clyde
Radio Recordings
RCA
Royal Opera House, Covent Garden
Sawmills Studio
S.B. Independent Radio London
Starlight
Thames Television
Theatre Projects for Palace Theatre
and Royalty Theatre
The Manor Studio
Threshhold Records
Trackplan Ltd.
TW Music
University of East Anglia
Worldwide Sound Studios
EIRE
Radio Telefis Eireann, Dublin
Send
for full information to
AKG
18214 Campden Hill Road
London W8 7AS. 01.229
3695.
seen from the
professional
angle
the 201 is something
quite personal ...
WHY CHILTON MIXERS?
The M 201 Hypercardioid moving coil
microphone is designed for recording or
broadcasting. The M 201 offers excellent
Separation characteristics in extreme
accoustical conditions.
We are manufacturers in the true sense of
the word; producing Teak Cabinets, Sheet
Metal Work, Tooling, Front Panel and Printed Circuit Artwork etc., our products are
accurate with an attention to detail that is
second nature to us.
The popular M10/2 (10in 2out) portable mixer
shown is supplied as a basic unit with 10 Line
inputs inc PPM, Oscillator, LF/HF Equalisers,
Aux and PFL. You choose the number of
Microphone or Gram inputs, the channels to
have Presence, Switchable HF/LF Filters or
Ducking. In addition a 2nd Aux channel,
Talk -Back, andior Compressors can be fitted.
1
Specifications:
Frequency Response: 40-18000 Hz.
Output Level at kHz: 0,14 mV/p, bar
-56 dbm (0 dbm
mW/10
dynes/cm2). EIA Sensitivity Rating:
-149 dbm. Hum Pickup Level:
5 It V/5 li Tesla (50 Hz). Polar Pattern:
Hypercardioid. Output Impedance:
200 2. Load Impedance:.> 1000 2.
Connections: M 201 N (C) = Cannon
XLR-3-50 T or Switchcraft: 2+3 -200
= ground. M 201 N = 3 -pin
DIN plug T 3262: 1+3 = 200 2
2 = ground. M 201 N (6) = 6 pin
Tuchel.
Dimensions: length 6", shaft Ci 0,95".
Weight: 8,60 oz.
1
1
2
1
.
Ring or write for full information, if however
our standard range is unsuitable it may be
possible to modify one to suit your
requirements.
M10/2 Mk4 BASIC
£350.00+VAT
input version
in 4 out Mk2
£515.00+ VAT
£565.00+ VAT
16
12
MAGNETIC TAPES Ltd., Chilton Works,
Garden Rd., Richmond, Surrey, TW9 4NS
Telephone 01-876 7957
10
STUDIO SOUND, JANUARY
1975
BEYER DYNAMIC (GB) LIMITED
1
Clair Road, Haywards Heath, Sussex.
Tel Haywards Heath 51003
:
The Delta -T 102 Series
with a 90 dB dynamic range
Four years ago Lexicon in cooperation with Gotham Audio
introduced the industry's first all electronic audio delay system
the Delta -T Model 101. Practical experience and helpful
suggestions from users accumulated since that time have enabled
Lexicon to create the Delta -T 102 Series. The 102's offer a new
level of performance and flexibility previously unavailable to
the industry.
Using proprietary digital techniques the Delta -T 102 Series
provides, along with other advances, a 90 dB dynamic range and
significantly lower noise and distortion.
The 102 Series has been carefully engineered to meet a wide
range of requirements:
For example, the system may contain 1 to 50 outputs, 2 ms to
3.2 seconds of delay, and remote console mounted controls and
-
Announcin
the secon
generation in
digital delay
systems...
headroom indicator. Fully modular construction permits simple field
expansion and maintenance by module plug-in. Three basic
models in the 102 Series allow economic selection of frequency
response and delay interval for sound reinforcement, studio and
laboratory applications. All models feature a 5 position 40 dB
headroom indicator which assures correct level setting.
And the cost of the 102 Series is revolutionary. Although providing
the dynamic range of a 15 bit system, the 102's are priced
competitively with present 10 and 12 bit units.
Delivery is 45 days.
Contact in U.K., F.W.O. Bauch Ltd., 49 Theobald St.,
Boreham Wood/Herts WD6 4R2, Telephone 01-953 0091.
Elsewhere in Europe contact Gotham Export Corp.
741 Washington St., N.Y., N.Y. 10014, U.S.A.
s
XICOI1
Lexicon, Inc., 60 Turner Street,
Waltham, Massachusetts 02154, U.S.A.
Take two of these and kiss your
12
STUDIO SOUND, JANUARY
1975
Take a look at the MM -1100. The tape transport is
probably the most advanced ever for multi -track purposes. Low tape tension phase loop capstan servo.
Used in conjunction with the VS -10 Vary Speed Accy
the MM -1100 offers absolute repeatability. It will
even pull tape backwards in record/plug mode.
Connect to the Ampex ultra flexible 3 card electronics
system and the finest multi -track tape machine results.
-
Throughout the world the AG -440 series has long
been the standard of the industry in both mastering
and broadcasting. Now the AG -440C offering many
new features continues its role as true professional.
AMPEX (GREAT BRITAIN) LIMITED
Acre Road, Reading, Berkshire. Tel: (0734) 84411 Telex: 848345
recording headaches goodbye.
AMPEX
AMPEX Worldwide
<'
The Better Memory People
Audio & Video Tape Recording Equipment; instrumentátion.;Computer Tape Drives; Core Memories; Disk Drives; Magnetic Tape.
13
PSTEAD
FO .ZT-E
-IG-
FIDELITY
lIC-EST QUALITY
I
SIC MICOP-ONES
Main distributors of STC professional microphones. The complete range
available from stock. Professional terms available.
is
HAMPSTEAD HIGH FIDELITY
Heath Street, Hampstead, London NW3 6SS
Telephones 01 -435 0999 and 01 -434 6377
91
4105
hHIl
Cardioid
microphone
Small, lightweight
and robust,
4 suitable for high
quality sound
reinforcement
Impedance 30 0
4037AEtC>
4104
Omnidirectional
Broadcast,
Moving coil
Frequency
quality corn
mentator's n
cancelling lip
microphone
response 30 Hz kHz. Sensitivity
-84 dB ref IV
:
1
Sensitivity -84 dB
ref IV. Impedance
30 or 300 S2
A highly damped
ribbon unit ensures
freedom from non
linearity and low
frequency surges
2
:
Suitable for
interviewing
4115
Lightweight Broadcast
quality noise cancelling
ribbon microphone
Impedance 30 f2
Sensitivity 85 dB ref IV
TOP
4001 G
High frequency pressure
unit
4021
Omnidirectional
Moving coil 40 Hz 12 kHz. Impedance
15 f2 as used by
leading loudspeaker
manufacturers
BOTTOM
4001
K
High frequency pressure
:
30 0. Output -80 dB
ref IV/dyne/cm2
:
unit
8
S2
as used by
leading louuspeaker
manufacturers
14
STUDIO SOUND, JANUARY
1975
irectional
15 kHz
Impedance 30
0 Hz
Ribbon
-
:
S2
or
300 0. Output: -80dB
ref IV at 30 f2
,e'KCe
IS
BROADCASTING
AM/82B. Continuity Desk
A complete range of Ancillary Rack Mounting Equipment. Multitrack Mixing Consoles
& Transcription Units are available at our usual speed & guaranteed deliveries.
1g&
(Stancoil Limited) Alexandra Road, Windsor, England
Tel. Windsor 51056/7
DESIGNED AND MADE IN THE U.K.
MULTI -CHANNEL EQUIPMENT
We have set a new price/performance standard with our 4, 8 and 16 channel studio
recorders offering full facilities for the production of master recordings. PPM or VU
meters on each channel. Equalisation to CCIR, NAB and IEC characteristics. Remote
control for tape transport and record functions. The equipment is in full production and
studio use in both U.K. and overseas.
STUDIO RECORDERS
for 2 -channel reducing, field recording and full track mastering.
TAPE TRANSPORTS
We offer a widened range of 2 speed and 4 speed modules from 15/16
to 60 IPS, 8" to 1" tape width, with heavy duty solenoid operation and
remote control facilities.
br'iarirII
BRENELL ENGINEERING CO LTD
231-5 Liverpool Road, London N1 1LY Tel. 01-607 8271 (5 lines)
15
Two years ago we introduced the first
programmable mixing system.
Two years later we're proud to introduce
A fully-integrated system in our mixing desks.
Compumix II. It wasn't easy.
Pictured: Armin Steiner
Sound Labs, Hollywood
CompumixlM Recording & Mixdown Console
inputs, 24 outputs, VCA sub -grouping
32
Quad/eugh[ e[ec[ronucs
11929 Vose Street, North Hollywood, California 91605
Telephone: 213/764-1516
The Studer 189 Quadro Makes Sound Sense
*
*
*
*
*
No fuss and bother about
specification
Realistic Price
Instant Delivery
Renowned Studer Quality
Any Questions?
All the details have already
been worked out for you
Due to streamlined Production
-2-6Weeks
- Ask anyone
Phone or write
STUDER F.W.O Bauch Limited
49 Theobald Street, Boreham Wood,
Hertfordshire.Tel:01953 0091
17
SNS
introduce their
new OLYMPIAN
radio microphone...
-the last word in
sheer professionalism!
From the professionals, for the professionals, comes
the wide band radio microphone that provides complete
freedom of expression and absolute reliability. No awkward leads or connections whatever, rechargeable batteries,
incredibly lightweight (only
7'/z ozs)
- and
a
truly
professional standard of audio quality. High stability.
High quality AKG Electret microphone head. Non -slip
satin anodised finish. The Olympian transmitter, with
receiver incorporating an integral battery charger, travels
complete in a shoulder slung, fitted, carrying case.
-
-
MORE THAN A MICROPHONE
A SYSTEM
The new SNS wide band radio microphone is the
perfect complement to a complete SNS entertainment
system which embraces the Chorale high quality vocal
mixer amplifier and the Distinctive Strauss
range of column or cabinet speakers,
... the choice is [Çjrampia)
SOUND EQUIPMENT
o
Find out more about
the big sound of SNS
GRAMPIAN REPRODUCERS LIMITED
HANWORTH TRADING ESTATE, FELTHAM, MIDDLESEX.
TELEPHONE: 01-894 9141, GRAMS: REAMP FELTHAM
ONE INCH SCOTCH
206
(Ex master once used)
10+" NAB
f9.50
QUARTER INCH SCOTCH
206
(Ex master once used)
102" NAB f3.00
P
SNS Electronics Group, 851, Ringwood Road,
&
P
10p
AUDIO TRANSCRIPTIONS
Northbourne, Bournemouth
BHI I 8LN. Tel. (02016) 5331/4.
London Sales Office: SNS House, Belmont Circle, Kenton Lane,
Harrow
Tel. 01-907 0057/9. Telex 923224.
177
Torridon Road, London
01
SNS ENTERTAINMENT SOUND SYSTEMS
SE6
697 0079
ITick the items that interest you,
and return the list to the
address above. No strings attached.
D Olympian wide band Radio
Microphone Systems
High quality CHORALE
Vocal Mixer Amplifiers
Distinctive STRAUSS
Cabinet and Column
Loudspeakers
Heavy Duty Loudspeakers
CABARETTE Gram and
Microphone Mixer Console
18
.
Instrument Amplifiers
Other
Address
Tel
lAte
STUDIO SOUND, JANUARY
1975
*
Dolby A36I for
* REVOX A77 Mk
Name
1
-
DISCO High Power
Sound Systems
Professional Graphic
SS/1/75
1
1
Ill
hire*
Recorders, standard and high speed
model in stock. Sel -Sync model available.
* New REVOX A700 1372 and 1374 now available.
* NEAL 102 professional cassette deck from stock.
* All leading equipment at competitive prices including
A.K.G., Beyer, Ferrograph, Teac A3340, Quad,
Spendor, Uher 4000/4200/4400, Report IC, andTannoy,
cassette recorder with facility for chrome tape. CR210
131 The Parade, High Street, Watford
WD1 INA
Tel. Watford 34644
BAILEYS
Not every country qualifies.
And we had pleasure in
delivering a 28 input
24 -track A series console.
Superbly engineered,
ergonomic and flexible.
The best we could
produce.
So they could produce
the best.
Anyone who has enough
style to build a studio in a
lakeside forest deserves
the best.
And Le Studio Morin
Heights has just that.
They specified a Triad
mixer for this beautiful
purpose-built studio.
,äk
TRIAD
More than most guys can handle.
Trident Audio Developments Limited, 4-10 North Road, London N7 9HG 01-609 0087 Telex 27782.
19
Condenser Microphones...
at greatly condensed prices
Yes it's true Unisound Electret Condenser Microphones
are capturing the sound and the interest of the amateur
and professional recordist, for at last the condenser
microphone price barrier has been shattered and without
any loss of performance.
The range includes Omni and Uni -Directional as well as
Tie -Tack lapel models. The unique design employs a tiny
UM-3 battery making bulky power packs obsolete yet
providing sufficient power to maintain high sensitivity and
a wide response ratio.
Get to know more about Unisound Electret Condenser
Mikes - we have a very interesting technical leaflet
available on request.
!
Y-.
-.....
Condov ec--
The fastest bird in the business
Condor Electronics Limited,
Lane, London, SW20 OAY
Telephone: 01-946 0033 (4 Lines)
Distributors of cartridges, styli, condenser
microphones and headphones. Guaranteed
24 -hour dispatch service
100 Coombe
L
-1111111111111111111111111I1111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111!
BIAS RECORDERS
EE
"sounds perfect"
f.
FOR PEOPLE
WHO WORK WITH TAPE
BIAS ELECTRONICS LTD.
572 KINGSTON RD., LONDON
Write now for the full details.
E.
01
540 8808
SW20 8DR
NOW AVAILABLE IN U.S.A. FROM
MUSTANG
COMMUNICATIONS
ACOUSTIGUIDE CORPORATION
NELSON STREET SCARBOROUGH
YORKSHIRE
YOI2 7SZ
(212) 988 3016
Telephone (0723) 63298
210
EAST 86th St., NEW YORK, N.Y.
1111111IIIiIII11111111111111111111111111111IIiIIiIIiIIII1111111111111111111Ii1i111lIIII111111iIIII11111111111111111I111111-
20
AT LAST your search is over. If second
best just will not do, you should be using
our range of high reliability equipment
which includes power amplifiers, 100v. line
transformers, microphone transformers,
rack cabinets, and some superb electronic
lighting control units. Deliveryusually ex-stock.
STUDIO SOUND, JANUARY
1975
mcron
800
SERIES
RECORDER
Prevents tape breakage by
providing fool -proof operating controls.
Feather touch push-button mode controls.
Photo -cell, automatic shut-off in all modes.
Take-up reel motor shut-off switch for editing.
Motor shut-off switch (electronics remain on).
Cue lever for controlling tape -to -head contact.
Professional styling and colour combinations.
Fully remote controllable.
Patented electro -magnetic brakes.
Plug-in modules for all functions: mic modules optional.
Built in remote record (CX-800's) for no thumps on tape at
beginning or end of record mode.
Echo controls built in.
Front panel bias adjustment.
3 -speed equalization.
Treble and bass controls with "flat" detents.
Available with 600 or 250 ohm balanced XLR cannon
inputs and outputs as an accessory.
* Computer Logic Control.
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21
The Big PDM-Compressor
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Compact compressor with
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EMT 257
Compact limiter featuring
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NEW: EMT 258
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EMT 258 delivery:
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Reverberation units
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Digital audio signal delay units
Auditorium microphone winch systems
Electronic tuning fork and polarity tester
Test equipment for wow and
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It's so good, it writes its own testimonial.
Philips monaural N8500
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If you have a cassette or reel-to-reel
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Simply years ahead.
23
This one does
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Ernest Turner 642 meters
Equalisation on
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Fully flexible
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!iIJLFIUIJ!!i!
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Manufacturers of Response sound mixing equipment
24
STUDIO SOUND, JANUARY
1975
The New
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Never has so much been
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Line out Attenuators
Output levels to +20dBm
55dB overload margin
Less than 1% distortion
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2nd echo panel
Electronic Splitter for high quality PA
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phase push button on input channels
Two echo -send paths (one fitted)
Available shortly:
Two fold back paths
Equalisation on fold back
XLR connectors
Equalisation on Echo
Ernest Turner 642 meters
A range of panels for broadcast purposes,
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-
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For further information contact DICK CULLUP at
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Manufacturers of Response sound mixing equipment
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26
STUDIO SOUND, JANUARY
1975
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4 OUTPUT CHANNELS WITH SWITCHABLE &
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RELATIVE INPUT NOISE REFERRED TO A 200
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27
So often when a recording
engineer wishes to choose a
microphone for a particular
purpose, it is more a question of
what is made available to him
than what is the best mic for the
job. In many cases studio
managers have chosen microphone
types with only limited
applications for use by engineers.
For example, one London studio
originally had available
only two types of microphone,
moving coil and capacitor, both
being fixed cardioid. Several
dozen of these were bought from
a single manufacturer, and
engineers soon grumbled at the
limited choice.
The
right
mic for
the job
ANGUS MCKENZIE
28
STUDIO SOUND, JANUARY 1975
IDEALLY MICROPHONES SHOULD be
chosen purely on a performance basis but
frequently, for prestige reasons, a studio will
buy, for example, Neumann, for some application where an AKG microphone might be a
better alternative. Some types of microphone
seem to be associated only with particular
sections of the recording world. For example,
Sennheiser rifle microphones are used almost
exclusively by film and TV studios, although
in the last year or so the BBC and IBA have
been introducing them for news coverage.
Only recently has BBC sound radio started
using them at Glyndebourne, for instance, to
obtain more presence in special conditions.
Often it will need just one well-known engineer
to start using a new microphone for that model
to become widely accepted and used.
There has been much said about actual
microphone techniques, and although I personally prefer to use the minimum number of
microphones possible, ideally only two,
nevertheless for a particular recording because
of acoustic conditions in some locations one
may have to use a very large number, even for
classical music. A hall having too much shortterm reverberation can produce a sound
quality, with a single stereo pair, which can
only be described as boring and wishy washy,
while on the other hand to use more than a
single pair in the Royal Albert Hall, or even
Ely cathedral, is only necessary if the forces
being recorded are not appropriately balanced
internally, or if one is working with a producer
who wants to create an effect for a gramophone
record, rather than attempting to reproduce
reality. Often such an effect is more exciting,
even if it offends the purist, but nevertheless
many engineers will not give simple techniques
a try. On the other hand, I have heard 'semiprofessional' engineers with modest equipment,
perhaps consisting of one stereo microphone
and one professional tape recorder, becoming
arrogant, and claiming that anyone using more
than a single pair for stereo is always wrong.
My reply would be: let him try to make a
recording of a large orchestra in the new Hove
Town Hall, or the De Monteforte Hall in
Leicester, with its serious flutter problems.
Choosing the right microphone must become
an art and not a science, a personal opinion
and not a text book matter, and should
become an engineer's personal choice, and not
company policy. In spite of this, there are
clearly some basic rules in choosing microphones, which are all important, and failure
to observe them may well create problems so
severe that no amount of knob twiddling can
repair the damage done by making a wrong
decision.
Although capacitor microphones have now
become a mainstay in most studios, the moving
coil cardioids remain very popular. Ribbon
mics are still being made, but in decreasing
quantities, though this doesn't mean they
are unsuitable for use today.
The polar
diagram of an STC 4038 ribbon is almost
perfectly bi-directional at all frequencies.
Many engineers like to use this polar diagram
to allow a ribbon mic to pick up brass instruments on the main axis while excluding loud
percussion instruments on the side. Because
these microphones have a very flat response
up to 10 kHz or so and then fall off rapidly
they are often liked by engineers for use with
woodwind when a close capacitor type might
over-emphasise breathiness. Although such
breathiness can be reduced by equalisation, I
have always felt that there is something about
the sound of a ribbon mic which is very
`musical'. Often, I have been asked by a
professional violinist to use a ribbon rather
than a capacitor for a solo pick-up. Beware,
though: the ribbon microphone's enormous
magnet can damage master tapes and even
unrecorded tapes, by introducing a dc magnetisation which cannot easily be erased.
Almost all ribbon mics are purely bidirectional, although the RCA Varacoustic had
a shutter at the rear allowing a choice of
effective polar diagrams to be obtained acoustically. Bi-directional ribbons will give a very
noticeable bass lift to close speech. I have
always noticed a tendency to high frequency
coloration sounding almost like a peaky
resonance, and have associated this with
acoustic resonances around the magnets and
between the front and back meshes covering
the microphones. In any case, good omnidirectional microphones give a far better
speech quality than any other types, for they
usually avoid p -blasting and other air exhalation effects. They do not in general require
wind shields, which can cause hf loss, and
sound more natural without the low frequency
boost created by velocity and cardioid polar
diagrams of all types. However, omnis are the
most difficult to mix in with a general multimic
balance, for they introduce serious phasing
problems at low frequencies, and are also
prone to rumble pick-up.
Ribbon and moving coil microphones have
a very low output, and therefore require
extremely well screened microphone cable and
microphone preamplifiers in the control desk
having a low inherent noise. They give an
output some 20 dB lower than the average
capacitor type, and some control desks will
not have sufficient gain for them when they are
used for recording very quiet speech sounds.
However, they can give high output levels
without distortion, and moving coil cardioids
in particular are useful for close miking pop
groups. Since these obtain the cardioid polar
diagram acoustically, they are often prone to
handling noises, and in any case the polar
diagram can change if the shank of the microphone behind the front is obscured by a hand,
or by a clamp covering the air holes. I have
found some types rather prone to shock
damage; in particular the AKG D202 used to
have very fine wires connecting the treble and
bass diaphragms to the cross -over unit (this
has since been improved). These wires broke
very easily, and so in general use often required
maintenance. Nevertheless, the AKG D224
seems more robust in this respect, although the
internal wiring is similar. Interwoven screened
cables are particularly suitable for moving coil
and ribbon mics, but they should not be run
close to any mains wiring. Some microphones
are available with either Cannon -type connectors or DIN ones. In practice the DIN plugs
are much more difficult to wire up, and are
less reliable, so I would advise sticking to
Cannon terminals. Many of the mics are
available with either socket.
Capacitor mics must be handled with care
and stored if possible in a reasonably warm
environment where the humidity can be kept
low. If stored for any length of time they
should be switched on some hours before use
in a warm place to remove any moisture from
the diaphragm. In this way noise and rumble
can be kept to a minimum. Capacitor microphones fall into three groups-those having
single polar diagrams, those having switchable
polar diagrams on the microphone, and those
having the polar diagram controllable remotely.
The first type includes the well - known
Neumann KM84, the AKG 451/452 series, the
Calrec 1050 series, and various models made
by Schoeps, Sennheiser, STC, Pearl etc. Of
these, the Neumann KM84 has a very low
inherent noise and a wide frequency response
without peaks and a good cardioid. When
bought in small quantities, however, it is an
expensive microphone. The AKG range has
two types of amplifier body, one for 9.5V
phantom powering, and the other for the more
conventional 48V. There seems to be virtually
no difference in the performance of the amplifiers, but the first type is suitable for use with
the AKG battery power box using a PP3
battery, which also contains a 1:1 isolating
transformer. A number of different heads are
available to suit most purposes.
The CK1 capsule is an acoustic cardioid and
is rather more noisy than many other types,
although it sounds very smooth. It is particularly useful for close miking, and the cardioid
pattern is fairly well maintained at different
frequencies. The CK2 capsule, an omni one,
is my personal favourite for speech recording.
It has an exceptionally fine pattern at all
frequencies and a very flat and uncoloured
response. The CK5 capsule has a built-on wind
shield incorporating bass cut, and is particularly useful for pa work, whereas the CK8 is a
hyper-cardioid capsule having a 20 cm plug-on
stem. The CK9 is a rifle -type microphone head
having high directivity at higher frequencies.
AKG can also supply a swivel adaptor type
A51 which allows the capsule to be pointed in
any direction relative to the amplifier body.
This allows two capsules to be mounted at a
110° included angle with their amplifiers run-
ning parallel and strapped to each other for
stereo. Short and long extension tubes VR1
and 2 are available so that the capsule can be
several feet above a vertical amplifier body,
perhaps on stage, so that the mic itself becomes
almost unnoticeable from a distance.
The AKG 414 capacitor mic is normally
supplied to work off 9.5 to 12V phantom
powering, but can be driven from a 48V
phantom supply, provided that resistors of
approximately 5.6k ohms are used to feed the
supply to each leg in the microphone input of
the mixer. The resistors should be of 1W rating
and the phantom supply should be well capable
of giving the extra current required without
any extra ac ripple. The 414 has four switch able polar diagrams, omnidirectional, bidirectional, normal cardioid and hyper cardioid. The last position is most unusual on a
mic not remotely controllable, but is nevertheless used probably more often than omni or
bi-directional by most people used to the mic.
The position was added at the request of the
BBC and other professional users when its
predecessor, the 412, first appeared.
The Neumann U87 has three polar diagrams
(missing out hyper-cardioid), is larger than the
AKG, but also has provision for internal
battery operation which is most convenient.
A comparison between these two mies is
included in this issue. Remotely controllable
polar diagram mies seem temporarily to be a
little out of fashion, although I cannot understand why. I have found it a great convenience
to be able to change a polar diagram in a
control room as an audience perhaps fills a
concert hall more than expected. By remotely
altering polar diagrams and using stereo
widening and narrowing in a control desk, an
equivalent to physically altering the angle
between the capsules can almost be obtained,
which probably could not be done during a
live performance.
The Neumann SM69 and other stereo
coincident capsule microphones all have
remotely controllable diagrams, and their
capsules can be set at any angle relative to
each other. AKG will be introducing an
updated fet C24, and Pearl and Sennheiser are
also making stereo models. Although the
convenience of having one stereo mic cannot
be underestimated, it is probably better,
because of flexibility, to use two separate mies
in close proximity, provided that remote
control facilities are not of great importance.
Remote control unfortunately adds quite a
considerable amount to the cost, although an
advantage is the availability of switchable polar
diagrams in steps between the more usual ones.
Although most bi-directional patterns are
30
29
RIGHT MIC
held over a wide frequency range by various
microphones, some mics exhibit slight bass
loss. At very high frequencies the diagram
falls inwards slightly. Cardioid microphones
vary greatly in their pattern performance at
different frequencies, and I have noted that
the AKG D202 seems to be particularly good
in the middle, pretty good in the bass, but gets
rather narrow at the extreme top end. Cheaper
moving coil cardioids normally tend to lose
their pattern at lower frequencies, although
they become highly directional at high frequencies; this can often be useful. A number of
users have found that the U87 bass cardioid is
not too good, and have preferred the AKG 414.
A good low frequency cardioid is important
when it is required to cut rumble out of the
microphone pick-up, particularly in tv studios
or large concert halls.
A good high frequency cardioid performance
is particularly important when cardioid microphones are to be used in pairs for stereo, since
a narrowing of hf polar diagrams tends to
exaggerate width at high frequencies, thus
giving incorrect positioning to sounds slightly
left and right of centre. Whereas sounds at the
edges will appear very lifelike, a tendency to
dullness in the centre will also be noticeable.
This effect is exaggerated as the angle between
the mics is increased, and frequently reaches
an absurdity when the microphone capsules
are back to back. This technique is nevertheless used sometimes when considerably more
ambience is required in the general sound,
when good mono compatibility is important,
and when degradation of stereo image is
acceptable. I prefer to use small capsule
capacitor mics for stereo pairs if the accuracy
of image is very important, and well remember
the excellent positioning obtained from the
Neumann SM2 stereo microphone, which is
unfortunately no longer available. This microphone, though, seemed to have rather an
apparent bass loss when used in bi-directional
polar diagram.
Bearing in mind the excellent sounds that
can be obtained from two cardioids in close
proximity, with an included angle of 110° or
so, some enterprising manufacturer might
make a simple stereo cardioid model having
one rotatable capsule. Although it would be
preferable for it to be a capacitor type, a moving
coil could give good results, although it might
have rather an odd shape in order to preserve
the polar diagrams at all frequencies (which
incidentally would have to be achieved by
acoustic means).
While discussing polar
diagrams, I would like to disagree with the
practice of some recording organisations in
using a multitude of omnidirectional microphones to obtain a stereo balance. The path
difference at low frequencies can give very
strange cancellations and additions, and
accurate positioning at high frequencies can
only be achieved by the use of further mics.
Recordings made with this type of technique
seem to reproduce with a very `woofy' bass and
lack real positional definition; such positional
clarity as exists is forced by multi miking.
For those concerned in comparisons I would
like to suggest comparing the stereo sound
obtained by the BBC at St. John's, Smith
Square, London, in which they normally use
30
STUDIO SOUND, JANUARY 1975
coincident mics, with that achieved by the
commercial companies in the same venue.
Omni mics also pick up more rumble than
directional ones, and this can become very
wearing when listening to records on good
quality equipment.
the choice of capacitor microphone powering
Originally, when capacitor microphones
were valve powered, separate mains power
supplies were needed, and multicore cable
connected the mic to the power supply. Now
that virtually all capacitor mics have fet preamplifiers in them and include, in the mic head,
means of converting lower voltages to the
necessary high ones, for polarisation purposes,
it becomes possible to power directly from the
control desk. Although the most popular
system, known as phantom powering, supplies
positive dc to the microphone head on both
live audio leads with a dc return via the screen,
a few other systems are in use.
Sennheiser, among others, send positive dc
on one audio leg and negative on the other,
and the screen purely prevents hum, rf and
static pick-up. The disadvantage is of course
the possibility of a disaster occurring on
accidental phase reversal coupled with failure
of protection components, but nevertheless the
system offers some important advantages.
Since in a normal phantom power microphone
the dc returns along the screen of the mie
cable, any slight oxidation in connectors or
screening can produce rectification of any rf
in the vicinity, and thus cause quite serious
interference. Although this can sometimes be
eradicated by using 1:1 transformers near the
microphone, with centre taps shorted together,
and decoupled from screen, there is always a
danger. In addition, a complete break in the
screening will render the microphone inoperative, and this unfortunately happens rather
frequently with some types of connector. I
have had, for example, a lot of trouble with
the AKG 412 and 414 connectors, and I cannot
see why these cannot be changed to Cannons.
The a/b powering system is usually 12V, and
even if the screen becomes disconnected the
mie will still work, although hum might be
noticeable. The screen, if connected well to
the microphone chassis, seems to give an
improved rf screening, which is quite important
when working near transmitters. Since there
are tens of thousands of these around-both
professional and amateur-the danger should
not be underestimated. For example, Decca
at their West Hampstead studios had continual
trouble with local radio amateurs before a
mutual understanding was reached. With
trepidation, I must add that I am also a radio
amateur, but I hope I have never caused such
interference.
The choice between 48V and 9.5V phantom
powering is difficult, but basically rests on the
ease with which 48V power supplies can be
made ripple-free, and the fact that 48V microphones draw only a minimal current, as
against the advantages of 9.5V mies being
operated in an emergency by battery power
supplies run from easily available PP3s. Future
Films, however, distribute a useful Pearl 48V
power supply at a very reasonable cost, which
uses two 24V batteries in series. We usually
take these out on mobiles in case of any
phantom supply fault on the desk. Most 9.5V
capacitor mies obtain their internal ht from
an rf oscillator driven from the 9.5V input, the
oscillator transformer secondary supplying
adequate voltage at low current to a rectifier
smoothing circuit. Such mies can therefore
have quite a high polarising voltage available,
whereas some 48V mies are limited to that
voltage for polarisation. The practice of using
negative 12V phantom power supplies as used
by one or two Continental firms is unfortunate;
I can see no purpose in it, and any confusion
can be serious.
Frequency response
Whereas moving coil microphones tend to
be rather peaky towards the higher end of
their response, and often have a bass response
tailing off somewhat sharply, ribbon mies are
much smoother but lack extreme top. Capacitor
mies are almost always much smoother
throughout, but seem to have very definite
shelf boosts from 1 kHz or so up to 10 kHz.
In general, the Neumann range seems to have
such presence boost, whereas AKG mies are
much flatter. Nevertheless, the Neumann
KM84 cardioid is one of the flattest mies available. A shelf boost can sometimes be useful
to achieve a special effect, and was originally
designed to offset high frequency losses in air
when mies were used at greater distances. Over
the years, however, engineers have used mies
closer and closer to the sound source, and
such boosts are no longer necessary since they
can be introduced in a different form in a
control desk.
Unfortunately it is much more difficult to
take away a shelf boost than to give presence
lift, since removal of the boost means a fairly
precise and opposite shelf which may be
difficult to set by ear. This phenomenon is so
important that it is worth quoting an example
which actually happened on a recording session.
A very beautiful harpsichord had to be recorded, a reproduction of an original instrument,
in a central London church. Both a Neumann
SM69 stereo mie and a pair of AKG 414s were
put out approximately 3m from the instrument;
subjectively both musicians and my recording
team agreed that the AKG reproduced the
sound more accurately. In that situation the
414s reproduced the delightful tang of the
instrument with a natural sweetness, whereas
the Neumann sounded twangy and hard. The
latter also seemed to bring up action noise;
even introducing various hf shelves did not
help, the main problem being that when any
shelf cut was introduced it became very
difficult to bring up the 15 kHz end of the
response adequately and steeply enough.
Although clearly a far more comprehensive
equaliser would have done the trick, it seems
hardly reasonable to be forced to take graphics
along to live recording sessions.
The very latest mies to be designed by all
good manufacturers seem to be reasonably
quiet, but I can remember 15 years ago having
a good AKG C12 which, although flatter in
response, was some 8 dB noisier than my
Neumann U47s. Some capacitor mies seem
to have a seriously coloured extreme top, but
as this seems to be a matter of opinion,
potential users should try various types,
especially on massed strings. For such an
assessment a loudspeaker with very low
coloration must be used, and probably the
best known examples are the Quad electrostatics and Spendor BC1s. A fair indication,
however, can be gained from a good pair of
electrostatic headphones, such as the better
models made by Stax and Koss. On low
frequencies many capsules obtaining their
polar diagram acoustically seem to exhibit a
loss, and a comparison between capsules on
the rhythm section will soon show up any
differences. Remember too that multi -polar
diagram mies usually exhibit bass loss in their
bi-directional positions. Unfortunately this
loss has a tendency to be rather more than
6 dB per octave below 80 Hz or so. Don't
forget, however, that an extended bass response
below 30 Hz can cause problems in disc cutting,
and cassette tape duplication.
Microphone sensitivity
Up to 34 dB difference in output has been
measured between the very highest sensitivity
capacitor microphones and some moving coil
and ribbon types. Remember that a microphone having a very high output may well clip
internally at high sound pressure levels. The
control desk to which the microphone is
connected must be capable of accepting very
high levels. At least 15 dB should be held in
hand on the control desk between the maximum
level registered from the mie and the clipping
level of the amplifier, since many sounds have
what is termed an extremely high crest factor,
this representing in dB the spikiness of the
wave form. Muted brass instruments sound
very much quieter than they actually peak, and
one example of a capacitor mie that can easily
distort internally on peaky wave forms is the
STC 4136 which has an output level of
approximately -50 dBm for a sound pressure
level of only 74 dB. Singers closer than a metre
to this microphone can cause distortion, and a
trumpet 30 cm away from the microphone
sounded extremely seriously clipped when I
tried it during some tests for this magazine a
few years ago. Clearly, this microphone had
too much gain in the pre -amp. Some mies
have switchable attenuator pads which act
before the fet and allow them to be used close
to very loud instruments. Most Neumann
mies have such pads, and now most other
manufacturers are introducing them.
Some capacitor mies have a rather low
output, such as the earlier models of Calrec
1050, only being 10 dB or so higher than
dynamic types. Noisy microphone amplifier
input stages will not have their input noise
overcome by microphone noise, and therefore
low output microphones should not be used
with them. Great care should be taken in
choosing capacitor mies for use with any
`domestic' recording equipment as almost
certainly such equipment has been designed
for use with dynamics, and capacitors will be
likely to cause overloading. Note that for
almost all capacitor mies having a nominal
output impedance of 200 ohms the attenuator
pad should have approximately 1000 ohms
input impedance bridging the mie, and an
output impedance of not higher than around
200 ohms.
Output impedance
As a rule in British studios, 200 ohm impedance mies should be selected for use with input
stages having an input impedance of 1000 ohms.
Most microphones will work satisfactorily into
600 ohms, but some models having their output
impedance increasing at low frequencies, or
having a variable impedance, may show
response irregularities. 60 ohm mies should be
used for mixers having an input impedance of
200-300 ohms. Make sure, however, that the
impedance stated for the mixer is not the
impedance of the microphone for which it has
been designed.
There seems to be little point in having
microphone preamplifiers with an input
impedance higher than 1.5k ohms, although it
is arguable that some mies might possibly give
slightly less output distortion at very high
levels when more lightly loaded. Some tape
recorders, such as the new Revox 700 and the
Nagra 4S have high input impedances on the
mie sockets, and this virtually discourages the
use of dynamic microphones with the Revox
because of noise problems, and of low output
capacitor microphones with the Nagra because
of insufficient mie gain. However, the Nagra
may be simply modified (details from Hayden
Laboratories).
Noise levels
Whereas moving coil and ribbon microphones require the quietest microphone preamplifiers into the control desk, capacitor types
all have an inherent noise produced by their
head preamplifiers. Capacitor mies in current
use vary widely in equivalent noise, the quietest
being most of the Neumanns, the Calrec series,
the Schoeps and the Sennheiser range, while
the noisiest appear to be the Neumann KM86,
the AKG 451 and C12A, and some Pearl
models. The very quietest mies are only
needed, however, when they are to be used at
a considerable distance from the sound source,
or when amplifying quieter sounds such as
speech, clavichords, church organs and distant
musical instruments. Although I have experienced occasional noise problems with the AKG
C24 and the 451, I have never had any trouble
with the 414 or microphones in the Neumann
range. Some Schoeps microphones have just
come to hand (see Reviews), and these have
proved to be most promising. The larger
Sennheiser rifle mies, like all other mies in the
range, are rf frequency modulation types
having a very low noise, and are extremely
useful for spotting distant instruments to give
presence. My colleagues have used them on
cathedral organs accompanying carols etc to
add some weight to the treble pipe work, which
would otherwise need close mies on an
incredibly tall stand. If rifle mies are to be
considered, I recommend that severe bass cut
is introduced with great care in stereo placement since at lower frequencies rifle mies lose
directionality and mixing them in flat could
cause phase problems at low frequencies.
Price considerations
The most expensive mies are frequently not
the best for a particular job, but as a rule it is
probably more useful to buy microphones with
three or more switchable polar diagrams,
rather than those which are not switchable. If
a number of microphones is to be bought, I
suggest including at least one stereo one in
addition to some pure cardioids. Inexpensive
moving coil types are always useful as a
standby, and many balancers like microphones
such as the Beyer M160 hyper-cardioid ribbon
and STC 4038 pure ribbon. It also seems
unwise to stick to only one manufacturer, since
each maker has his own forte. Ruggedness and
appearance are also important. Finally, but
certainly not least important, is the recording
engineer's own personal preference for a
particular type.
in this article have
heard that AKG are shortly producing a new 414
head connector coming out on an XLR socket rather
than a multi pin. This will be a great blessing, and is
a result of many complaints by users about the
unreliability of the present connector. The D202 has
very recently been modified to include a more
Footnote: just before sending
I
reliable internal choke, and some of the fine wiring
has been made more reliable.
31
KEY
Survey:
TRANSDUCER TYPE. MC -Moving coil. R -Ribbon. C -Capacitor.
EI -Electret. RC-Varactor(tuned circuitfm system). DR -Double ribbon.
POLAR RESPONSE. 0 -Omnidirectional. C-Cardioid. HC-Hyper-
microphones
Transducer lmpedModel No type
ance Output
cardioid. SC-Supercardioid. B -Figure of eight.
Various. VS-Various switchable.
Price
Remarks
ADASTRA
Adastra Electronics Ltd, Unit N22, Cricklewood Trading
Estate, Claremont Rd, London NW2 1TU. Phone: 01-452
6288/9
EX220
B7105
B7107
C
C
C
C
C
C
600
600
600
dB
dB
70 dB
70
70
£20.25
£24.30
£15.70
Windshield.
Windshield.
CK5
CK8
CK9
C451/2
C414E
MC
MC
MC
.16 mV/µB
.14 mV/µB
.13 mV/µB
.95 mV/µB
.8 mV/µB
.95 mV/µB
1.5 mV/µB
Two way system.
Two way system.
Two way system.
C
N/A
Condenser capsule.
C
O
N/A
Condenser capsule.
C
C
N/A
Internally suspended.
C
HC
N/A
Interference tube.
C
HC
N/A 1.1 mV/µB
Interference tube.
FET preamps for use with above condenser mic capsules.
C
V
.6 mV/uB £173
Polar response
C
C
C
C
300
250
250
Transducer Impedtype
ance Output
CM903C
CM950C
CM951C
CM956C
C
C
C
C
CB 9C
CM1050C
CM1051C
CM2001C
Self powered preamp, cannon
C
O
500
.8 mV/µB
C
0
500
.8 mV/µB
C
C
500
.8 mV/µB
C
C
500
.8 mV/µB
C
0
500
.8 mV/µB
CM2003C
CM2050C
CM2051C
C
C
C
O
C
C
500
500
500
.8
.8
mV/µB
mV/µB
mV/µB
£54.70
£54.70
£54.70
£54
£40
£72.40
CM2056C
C
C
500
.8 mV/µB
£54.70
CM2101C
C
0
1k
.6
mV/µB
£54.70
CM2103C
CM2150C
CM2151 C
C
C
C
O
C
C
1k
1k
1k
.6
.6
.6
mV/µB
mV/µB
mV/µB
£54.70
£54.70
£54.70
CM2156C
C
C
1k
.6
mV/µB
£54.70
O
C
C
C
N/A
N/A
N/A
N/A
mV/µB
mV/µB
mV/µB
.4 mV/µB
.4
.4
.4
Price
POA
POA
POA
POA
D21
D160
01200
D2000
C510E
C510E
MC
MC
MC
MC
MC
MC
MC
HC
.072 mV/µB
.23 mV/µB
.13 mV/µB
.22 mV/µB
C
C
C
O
.13
mV/µB
£31
.23
mV/µB
£39
£40
£52.70
C
El
C
C
El
O
fig. of 8.
Head only.
General purpose.
Head only.
Extended bass.
£20
£28
£28
£43
£73.70
Windshield.
Variable bass.
Designed for PA.
Interchangeable
cartridge.
Studio Lavalier-tie
pin.
BEYER
Eugen Beyer, Electrotechnische Fabrik, 071 Heilbron,
Thereseinstrasse 8, PO Box 170, Germany. Phone 07131
82348.
UK agents: Beyer Dynamic (GB) Ltd,
Heath, Sussex. Phone 0444 51003.
R
HC
HC
HC
200
200
200
-152 dBm
-153 dBm
-153 dBm
M101NC
MC
0
200
-150 dBm
M111N
M67NC
MC 0
MC C
200
200
-153 dBm
-148 dBm
M69NC
M201NC
X1NC
MC C
MC HC
MC C
200
200
200
-144 dBm
-149 dBm
-146 dBm
M160N
M206NC
M500NC
DR
R
1
Clair Rd, Haywards
£96.07
£46.99
£56.80
High front/back
ratio.
£48.24 Clamp and
windshield.
£53.89 Studio Lavalier.
£48.24
£36.15
£49.10
£31.84
Speech/music
switch.
Clamp/windshield.
General purpose
Hum buck.
CALREC
Calrec Audio Ltd, Hangingroyd Lane, Hebden Bridge,
Yorkshire HX7 7DD. Phone: 0422 84-2159.
CM901C
32
C
O
N/A
.4
mV/µB
POA
STUDIO SOUND, JANUARY
1975
Integral windshield.
-
Remarks
Extended response.
Extended response.
Reduced bass.
Reduced bass,
CM1003C
.8
fitting for above series.
£54.70
£54.70
£54.70
£54.70
£54.70
switchable-inc.
D58
D190
D590
V
windshield.
CM/00/C
AKG
AKG Akustische Und Kino -Gerate GmbH, A-1150 Vienna,
Brunhildengasse 1, Austria.
UK agents: AKG Equipment Ltd, 182/184 Campden Hill
Rd, Kensington, London W8. Phone 01-229 3695/6.
D202
D200
D224
CK1
CK2
Model No
S-Special.
Extended response.
Windshield.
Studio cardioid.
Reduced bass.
Windshield,
phantom.
Phantom powering.
Phantom powering.
Reduced bass,
phantom.
Bass, phantom,
windshield.
Windshield,
phantom power.
Phantom power.
Phantom power.
Reduced bass,
phantom.
Bass, phantom.
windshield.
CONDOR
Condor Electronics Ltd, 100 Coombe Lane, London SW20
OAY. Phone: 01-946 0033.
EM82
EM82H
EM83
EM83H
EM84
C
C
600
50k
1k
50k
-65
-46
-68
O
1k
-65
El
O
El
O
El
El
El
-51
dB
dB
dB
dB
dB
£12
£12
£13.80
£13.80
£12
Internal battery.
Internal battery.
Internal battery.
Internal battery.
Lavalier.
EAGLE
Eagle International, Precision Centre, Heather Park Drive,
Wembley HAO 1SU. Phone: 01-903 0144.
PRO M20
C
C
600
-60
dB
£32
PRO M10
C
0
600
-70
dB
£35
PRO M25
C
C
600
-70
dBV
£37.40
Complete with
clamp.
Complete with
clamp.
60 cm boom arm.
ELECTROVOICE
Electrovoice Inc, 600 Cecil St, Buchanan, Michigan 49107.
UK agents: Special Products Division, Gulton Europe
Ltd, Brighton BN2 4JU. Phone: 0273-66271.
DS35
MC 0
MC HC
MC C
MC C
150
150
150
150
-149 dB
-150 dB
-154 dB
-148 dB
RE15
RE16
MC
MC
C
C
150
150
-150 dB
-150 dB
RE20
RE55
MC C
MC 0
150
150
-150
-149
635A
660
671
dB
dB
£40
Broadcast, report.
Low cost bass effect.
High close bass
effect.
£99.50 Hum cancellation.
£103.50 Hum cancel,
anti -pop.
Low cost bass effect.
General purpose.
NEUMANN
Georg Neumann & Co, 71 Heilbronn/Neckar, Fleinerstrasse 29, Postfach 2120, Germany.
UK agents: FWO Bauch Ltd, 49 Theobald St, Boreham
Wood, Herts WD6 4RZ. Phone: 01-953 0091.
34
WHO'S WHO
IN SOUND
niesruoios
KEITH SLAUGHTER:
"Playback and recording
automatically includes the
appropriate noise
reduction unit."
PETER SULLIVAN:
"Capacitor microphones are
used to provide high quality
signals for talkbäck and
foldback circuits."
GEORGE MARTIN:
"The channel amplifiers hove
sufficient equalisation to
meet all advanced recording
techniques."
JOHN BURGESS:
"With the Neve unit we can
produce high quality quadrophonic
tapes for disc or film sound tracks."
BILL PRICE:
"There are 32 input channels
mixing down to 24 groups
'for multi -track recording"
e._
r"4r\
,
A>>>R>>N'NlNVN4
Who's Who in sound know what's what when it comes to a sound recording
system. Only the best is good enough for AIR Studios. Which is why they chose
Neve. This 32 input, 24 track quadrophonic music recording console was
specially designed to fit AIR's most advanced studio at Oxford Circus. It looks
magnificent. The results speak for themselves.
,A/ Neve internationally sound people
Rupert Neve, Cambridge House, Melbourn, Royston, Herts.Telephone: Royston (0763) 60776. Or Cambridge (0223) 53454. Telex 81381. Cables Neve Cambridge.
2719 Rena Road, Malton, Ontario L4T 3M, Canada. Telephone: 416 677 6611. 06968753
4822.
Berkshire Industrial Park, Bethel, Connecticut 06801, U.S.A.Telephone: (203) 7446230.Telex 969638. Hollywood Office: Telephone: (213) 465
33
V
200
200
200
-46 dB/Pa
-44 dB/Pa
-60 dB
POA
POA
POA
C
C
C
C
C
200
200
200
-40
-46
-61
dB
POA
POA
POA
EC71
C
C
200
-58
dB
POA
EK71
C
O
200
-58
dB
POA
FP92C
El
C
200
-66
dB
POA
DC20
DC21
DC63
C
C
C
O
DC73/12
DC73
DC96
C
C
dB/Pa
dB/Pa
Variable polar
pattern, inc. fig. of8.
10-50V powering.
Low noise, 130 dB
dynamic.
Miniature high
performance.
Miniature high
performance.
Self contained
battery.
Internal 15V battery.
Internal 15V battery.
Variable rolloff. 15V.
Variable rolloff.15V.
V
120V. Dual unit for
coincident stereo.
TC4
C
C
200
-52 dB
POA
120V. Very high
performance.
VM40
C
O
200
-48 dB/Pa POA Speech/music/
-10 dB switch.
VM41
C
C
200
-48 dB/Pa POA Speech/music/
-10 dB switch.
Interference tubes supplied for SP85, VM41 only as complete unit.
Unless otherwise stated, mic power supplies are 48+6-8V phantom.
FP92CO
FP92KO
SP84
SP85
ST8
C
C
C
C
C
C
O
O
C
200
200
200
200
200
-38 dB/Pa
-42 dB/Pa
-42 dB/Pa
-42 dB/Pa
-46 dB/Pa
POA
POA
POA
POA
POA
PHILIPS
Pye Business Communications Ltd,
Cambridge CB1 3HE. Phone: 0223-45191.
EL6042
LBB9005
LBB9050
LBB9101
Above:
C
0
C
C
C
C
C
C
VS
VS
U87
C
C
VS
U47fet
C
C
200
200
200
200
200
150
200
150
SM69fet
C
VS
150
C
1.0
1.0
1.0
1.8
.8
.8
.6
.8
.8
mV/µB
mV/µB
mV/µB
mV/µB
mV/µB
mV/µB
mV/µB
mV/µB
£91.72
£98.83
£98.83
£149.74
£149.23
£138.65
£150.73
£140.78
mV/µB
£332 75
Pressure unit.
Pressure gradient.
Rolloff
12 dB@ 50Hz.
dB atten. switch
dB atten. switch
High sound levels.
-10
-10
Rolloff 200/30 Hz,
-10 dB switch, 50
Hz rolloff switch.
Tandem transducers
for coincident
stereo
KMA
C
S
800
£87.45 Studio Lavatier.
All the above are for use with phantom powering from 48V dc.
PEARL
AB Pearl Mikrofonlaboratorium, Knutsgatan 6, S265 00
Astorp, Sweden. Phone: 042-515 20.
UK agents: Allotrope Ltd, 90 Wardour St, London W1 V 3LE.
Phone: 01-437 1892/3.
D441LS
LD18
RD16
RD34
F69
HM47
HM49
CL3
34
MC
HC
0
MC
MC
MC
MC
MC
MC
C
C
O
O
El
O
C
C
C
O
200
200
200
200
.12
mV/µB
.14
.16
mV/µB
mV/µB
£47.50 QD adaptor.
£28.
Hum compensation.
£33
Two way system.
£36
1050C
SURVEY
KM83
KM84
KM85
KM86
KM88
KMS85
O
Rd,
ROSS ELECTRONICS
Ross Marks Ltd 32 Rathbone Place, London W1P 1AD.
Phone: 01-580 7112/3.
STC 4038
Right: Calrec CM
MC
MC
MC
MC
Cromwell
200
200
200
200
200
200
200
200
-51
dB
POA
-74 dB
-70 dB
-74 dB
-70 dB
-76 dB
-74 dB
POA
POA
POA
POA
POA
POA
POA
STUDIO SOUND, JANUARY
1975
Windshield,
anti -pop.
Small size.
High output.
Studio Lavalier.
High performance.
Tie clip studio mic.
O
600
600
600
600
600
-54 dB
-55 dB
-57 dB
-72 dB
-62 dB
£9.66
£11.06
£11.06
£12.75
£13.59
C
600
-68
£14.91
RE325
RE330
RE335
RE345
RE360
MC C
MC C
MC O
MC C
El
RE365
El
dB
Dual impedance.
Dual impedance.
Dual impedance.
Anti -pop.
FET preamp/HP7
cell.
FET preamp/HP7
cell.
SCHOEPS
Feldon Audio Ltd 126 Great Portland St, London W1 N 5PH.
Phone: 01-580 4314.
CMT540U C
CMT441U C
CMT55U C
C
HC
O/C
1k
1k
1k
CMT56U
1.3 mV
1.3 mV
1.2 mV or
1.5 mV
1.0 mV
C
V
1k
CMTS501 U C
V
1k
32U
C
O
1k
2.O mV
34U
Cardioid version of 32U
340U
As 34U with If filter
331U
Hyper-cardioid version
CMTS301 U C
V
1k
CMT42
C
O
1k
1.5 mV
CMT44
C
C
1k
1.5 mV
CMT440
As CMT44 with If filter
CMT441
Hyper-cardioid version
35U
C
O/C 1k
1.9/2.3 mV
36U
C
V
1k
CMT45
C
O/C 1k
1.4/1.7 mV
CMT46
C
V
1k
1.O mV
CMT52U
C
O
1k
1.3 mV
CMT54U
CM62T
CM64T
CM640T
CM641 T
MK2
MK3
MK4
MK40
Cardioid version of CMT52U
C
C
C
C
O
C
O
O
C
C
C
C
C
C
C
HC
1k
1k
1k
1k
600
600
600
600
1.4mV
1.4
1.4
1.4
1.2
1.0
1.2
1.6
mV
mV
mV
mV
mV
mV
mV
£113
£115
£133
£146
£306
£119
If filter.
polar response sw.
stereo coincident.
£119'50
£122
£123
£112
£112
£112
£114
£115
£135
£153
£128
£150
£108
£108
£155
£156
£156
£156
POA
POA
POA
POA
stereo coincident.
polar response sw.
polar response sw.
polar response sw.
Capsule.
Capsule.
Capsule.
Capsule for speech.
Above: Pearl reed switches
Above: Millbank
Above: Philips
Left
MK41
MK5
MK6
C
C
C
HC
0/C
V
1.3 mV
600
600 1/1.2 mV
V
600
POA
POA
POA
L
0
0
200
200
200
200
200
200
1.5k
RC
SC
SC
1.5k
200
-52 dBm
-52 dBm
-56 dBm
-52 dBm
-58 dBm
-56 dBm
-32 dBm
-27 dBm
-32 dBm
MKH815T
RC
L
200
-26
dBm
£130
MKH125T
MKH105T
RC
RC
0
0
150
200
-32 dBm
-32 dBm
£153
£108
MKE201
MKE401
El
MKH415T
El
C
C
0
0
£69
£49.50
£39
£29.80
£50.85
£53.80
£32.05
£37.40
£130
Treble/bass switch.
Bass atten. switch.
Anti -boom.
Robust.
Lavalier studio mic.
40-20 kHz*2.5 dB.
5.6V internal battery.
5.6V internal battery.
12V phantom,
interference.
12V phantom,
interference.
Lavalier 12V.
20-20 kHz ±2.5 dB.
£133
2k
-32 dBm
RC 0
The MKH110 is intended for instrumentation in the range from
20 kHz. As such, a three volt dc offset exists on the output.
0.1 Hz
to
SHURE
Shure Electronics Ltd, Eccleston Rd, Maidstone, Kent
ME15 6AU. Phone: 0622-59881.
SM7
SM53
SM56
SM57
SM58
SM33
SM51
150
150
-81.5 dB
-87.5 dB
-78.5 dB
£31.80
£78
£50.40
Anti -pop.
Extended response.
Robust.
MC C
series
MC C
Unidyne II series
MC C
Unisphere I
MC C
Unisphere B series
Unidyne
H/L
.13
mV/µB
From about £39.
H/L
.12
mV/µB
From about £34.
V
.12
mV/µB
From about £34.
150
.14
mV/µB
From about £38 to £75.
Ill
315
300
R
R
B
B
H/L
H/L
579SB
MC
O
Low
.1
578
576
As 579SB
150
.094
MC
0
SONY
Sony Showroom,
134
£40.80
£66.60
£29.40
mV/µB
mV/µB
Extended response.
Regent St, London W1.
Phone:
01-439 3874.
ECM22P
El
C
250
1.5 mV
£59.95
600 ohm
alternative.
12V.
8V phantom power.
MK/VW
SM5B
SM5C
Low
Unidyne IV series
02403-5511.
HC
MC O
MC 0
MC 0
Most of the above are dual impedance.
Sennheiser Electronic, 3002 Bissendorf/Hann, Germany.
Phone: 05130-8011.
UK agents: Hayden Laboratories Ltd, Hayden House, 17
Phone:
Chesham Rd, Amersham, Bucks HP6 5AG.
MC
MC
MC
MC
MC
MC
& RE 350
SM60
SM76
SM50
SEN NHEISER
MD441U
MD421U4
MD413U
MD21N
MD214U3
MD211U
LBB 9005106
to R: Ross RE 345
Capsule.
polar response sw.
various polar
responses.
2255
MC C
MC C
MC C
MC C
MC C
150
-79.5 dB
50
150
150
200
-84
Hand held
MC C
SC
R
MC O
SM56.
dB
-79.5 dB
-81 dB
-76
dB
£165
£173.40
£148.80
£99
£159.99
Boom mounting.
100 Hz Hi -pass.
Boom mounting.
Hum buck, anti -pop.
Stand, extended
bass.
£4860
200
150
-76
Low
-82
-81
dB
dB
dB
£62.40
£97.20
£46.20
Shock proofed.
Stand.
Studio Lavalier.
STC
Hampstead High Fidelity,
London NW3. Phone: 01-435
4038
R
B
300
-85
4021
MC
O
300
-80 dB
4104
R
C
300
-80 dB
4115
R
C
300
-85
dB
dB
91
Heath St,
Hampstead,
6377.
For levels to 125dB
spl.
Studio and acoustic
ref.
Noise cancel, lip
guard.
Broadcast.
TURNER
Millbank Electronics Group, Uckfield, Sussex TN22 1PS.
Phone: 0825-4166.
150
MC 0
-57 dB
2203
150
-57 dB
2203
MC C
35
1121
ORTF Strike
has lost £15.1 million in the last
writing ORTF is two years. A colour version of
being hit by a series of strikes by 'The Sleeping Beauty', for example,
journalists. The first two day strike was shown in black and white after
was held on October 8 and con- the budget for the production had
tinued the next day. The journalists been
overspent
by £85,000.
have given notice that they will D'Estaing had promised before
hold another two-day strike on the election that, if elected, he
October 29 and 30. The strikes are would give the problems of ORTF
expected to continue until the top priority. He was as good as
journalists are guaranteed employ- his word. Indeed he acted so swiftment when the act which approved ly that opposition to the move was
the splitting of ORTF into seven in disarray. This opposition includseparate companies comes into es the trade unions, the press and
effect on January 1, 1975.
the left.
The journalists have learned,
They have opposed the plan on
according to one source, that the basis that the government wish
between 250 and 300 free lance to destroy the state monopoly and
journalists-one third of the free- set up a third channel dependent
lances who work for ORTF-and on advertising which would, they
about 200 of the 1050 contract say, 'be the death of French culture,
journalists will be made redundant. not to say deprive the press of
The journalists say that ORTF is advertising'.
When the bill to
not overstaffed, that the company authorise the dismemberment of
has fewer journalists working for ORTF was introduced more than
it than the BBC and the number is 100 amendments were tabled.
about the same as countries such Speaking in the debate M Chirac
as Italy, Poland and Yugoslavia. said the government wanted a free
'It has become very smart, very and democratic radio and telechic to say that we are overstaffed,' vision which were the property of
said one, 'but what people forget is no-one, subject to no private
that we have 23 provincial centres interest, but at the service of the
in France and a number of regional nation as a whole: 'We think that
centres overseas, which account for the state monopoly is the best
about 400 journalists. We have guarantor of the independence of
about 150 working in external a public service, but it must not be
broadcasting. Another thing is that a sort of comfortable protection
in France, cameramen are counted against competition.'
as journalists, but they are not in
Four state companies would be
England. There are three channels set up, he said, run by boards of
as well as all the regional centres, six members. Two of the board
which means more than 200 would be representatives of the
cameramen.'
state, one a member of parliament,
The external broadcasting service and there would be one each from
will disappear entirely when the the press, the staff and the arts and
new régime begins on January 1. literature. Three of these companies
Journalists were not reassured would each control one of the
when, on October 24, the director television channels and the fourth
general of the French commercial would be responsible for the radio.
radio station Europe One, M Each company would be responMaurice Siegal, was sacked and sible for its budget and programstrike leaders announced that their mes. A fifth company would
action would continue 'for as long 'administer the actual technical
as necessary' beginning on the means of broadcasting' and a
following Tuesday.
sixth would be responsible for
The splitting of ORTF into 'heavy' cultural production, for
separate competing sections was which it would be financed from
announced by Jacques Chirac, the public funds, for supplying progFrench Prime Minister, as part of rammes to the three television and
the new President M Giscard the radio channels in competition
d'Estaing's clean sweep, six weeks with commercial programme
after he came to office. There makers.
would be three television stations
The bill was approved on July
and three radio stations plus an 25 by 290 votes to 183 after some
audiovisual research institute. As heated exchanges when the left
we reported in September ORTF tried to block the bill, which was
36
STUDIO SOUND, JANUARY 1975
AT THE TIME Of
then sent tothe senate for approval.
According to reports, workers
in ORTF do not think the new
system will be financially successful. As far as advertising revenue
goes the old organisation was
limited to 25 per cent of its revenue,
the rest having to be made up by
the licence.
It seems, however, that the
ORTF had a great deal of difficulty
in bringing the amount of advertising up to the 25 per cent limit.
The unrest should be seen against
the background of a general feeling of insecurity in France, traditionally a country which reacts
strongly to low levels of unemployment that would be considered
unfortunate but unavoidavble in
other countries. An agreement was
signed on October 15 between the
French employers' federation, the
CNPF, and all the trade union
organisations stating that any
Frenchman made redundant for
economic reasons would receive a
year's pay, an agreement which
one report described as the first of
its kind that any working class
movement has obtained anywhere.
That has not assuaged the fears of
the ORTF journalists, however,
for they say that the payments will
be made monthly and that attendance will be required at a redundancy office, where the unemployed
man will be offered any job available. If he doesn't want the job his
redundancy payment will be cancelled, said one.
The coming reorganisation of
ORTF is the ninth in three years.
One journalist, asked if there might
be a tenth, said he didn't know.
The government is prepared for it.
In announcing the proposed
changes early in July M Chirac
said 'The hypothesis of transfer to
private ownership (of one television
channel) had its defenders and its
advantages. We considered, however, that the traditional mission
of the ORTF should not be brought
into question. It is a fundamental
option, but should it appear that
we had been mistaken, we would
go back on this option'.
Giscard d'Estaing is no less
determined. In his first presidential
press conference he said: 'A
country which has the cultural
tradition of France must have a
radio and television which are
among the best in the world.'
Mr Len Young
been announced of
Mr Len Young, the well known
and respected chairman of Vitavox,
at the age of 71.
Mr Young, who founded his
company in 1931, was considered
one of the great pioneers of the
sound manufacturing industry; his
avowed aim was always to produce
the best sound equipment available.
Since it was founded, his firm has
gone from strength to strength
and now exports to 34 countries.
Mr Young was a founder THE DEATH HAS
member of the APAE.
Low cost level meter
the sound
mixing equipment company, have
introduced a new level meter to
their range of products. Described
as a 'peak reading vu meter', this
instrument operates as a vu meter
with a faster than normal rise time.
This unit, which uses a Bach Simpson movement, produces a
0 dB reading with 0 dBm line
level. Power requirements are 24V
at 4 mA. This meter claims to fill
the gap between the conventional
vu and the expensive ppm system
of metering. Price is £8.32 from
Partridge Electronics Ltd, 21/25
Hart Road, Benfleet, Essex SS7
3PB. Phone: 03745-3256.
PARTRIDGE ELECTRONICS,
Compact broadcast console
a new 20
channel broadcast console arranged
into four groups with two outputs.
This desk, designated type 5301,
was first shown at the London
IBC and is claimed to be one of the
most compact units of its type in
the world. Taking up a mere 1.2m
of space, the desk is available with
a rack mounted patch bay for use
with ob vehicles; the other model
has integral patch bay and furniture surround for tv studios etc.
Rupert Neve & Co Ltd, Cambridge
House, Melbourn, Royston, Herts.
Phone: 0763-60776.
NEVE HAVE ANNOUNCED
Electronic music mag with a
difference
A NEW ORGAN, under the editorship
of Jacob Meyerowitz, intends to
put music back into the expression
'electronic music'. To be called
'Analog Sounds', his magazine
would ensure that their product
went on to the retail market at the
full recommended price. Recording
Materials Division, 3M United
Wycombe, Bucks HP11
electronics for its own sake.
totum-and by his own definition Kingdom Ltd, 3M House, WigThe quarterly issues will com- Phone: 0494-37529.
-`dogsbody'. Keith, who has an more Street, London W1A lET.
prise four distinct parts: method,
impressive track record from the Phone: 01-486 5522.
procedure, medium and process.
halcyon days of pirate radio, is
The first two parts concern themselves with the parameters of music, Bigger Theatre Projects Group responsible for defining much of AES Convention
its theory and practice. The last STAGESOUND LTD, the sound com- the musical attitude of Radio WITH AROUND FIVE months until
two sections will show and detail pany founded by the late Bill Hallam as well as presenting some the AES convention at the Cunard
the applications of electronics to Walton, has become part of the of the programme output in per- Hotel, London all the stands for
obtain the required effects. The Theatre Projects Group. TPG say son. In the latter task, he is helped the exhibition have been taken and
magazine is intended to be sequen- that the facilities of Stagesound by ex BFN, Lux, Beeb and Pinky nearly half the number of papers
tial; the four sections may be split are entirely complementary to their & Perky man Roger Moffat.
needed have been accepted. If
In common with other indepen- unofficial reports prove correct the
up and bound to make four refer- own interests, and it is hoped that
ence volumes. Published in the the addition will provide a more dent local radio stations, Hallam convention in London will prove
USA, the annual subscription efficient dubbing and editing service spreads its interests over a wide interesting from a number of
(four issues) is $15. 145 West 55th to the educational and industrial range. The station uses most of the points of view. The first is that the
Street (Apt. 6F), New York, NY training sector. Theatre Projects daily nine hours of needle time but number of papers has been restricGroup, 10 Long Acre, London still provides coverage for local ted so that no more than two will
10019, USA.
WC2E 9LN. Phone: 01-240 5411. events. According to Bill Mac- be read at any one time. The
Donald, much local interest second is that there has been a
revolves around sport; there are rejection rate of around 60 per
six football clubs in the service cent of those submitted. The rejecThree level sequencer
Mixing with the knobs
area which may help to focus local ted papers were considered either
ELECTRONIC MUSIC LABORATORIES Of
SIFAM, TRADITIONAL PURVEYORS Of
on Radio Hallam by pro- not technical enough, not suffiVernon, Connecticut have added meters to the electronics industry, interest
ob cover of the
extended
viding
step
or merely
16
by
a new three level
announced their entry into a matches. To give a sense of com- ciently novel in content,
have
descriptions of commercial
public
sequencer, the EML 400, to their new market with a range of collet
to those people who ventures.
range of synthesiser products. Of fixing knobs. The company spent munity spirit
football, Bill intends to
Some lectures will be an hour
modular construction, this unit will two years researching the range don't like
present local talent spotting prog- long and some half an hour, to
enable functions such as vc envelope resulting in a series of collet knobs
us).
call Bill, not
generators, vco, vca and vc filters available in diameters of 11, 15, 21 rammes (pleasewith the ilr network, allow a proper time for each paper
In common
according to the needs of each.
with three programmed voltages and 29 mm. The series has been
transmits on medium
for every note in a 16 note sequence. designed so that a smaller knob the station in vhf using circular This move has, apparently, upset
and
the American AES, which has
To create longer sequences, further will fit within the fixing recess of wave,
polarisation; this type improves proved very conservative in its
memory boards (type EML416) the next size up enabling use as a
the standard of reception on fm approach to this convention, as to
may be added; alternatively, they concentric pair. Manufactured in
portable radios that use a vertical others. But they were even more
can operate in parallel to provide several colours, most of the range
rod aerial. The station transmits upset when the London organisers
more functions per step.
is available ex stock. Sifam Ltd, from Tapton Hill on 95.2 MHz,
told them that all the papers would
To create a stepped synthesiser Woodland Road, Torquay, Devon
and from Skew Hill on 1546 kHz. have to be presented with a preprint
within a synthesiser, an EML401 TQ2 7AY. Phone: 0803 63822.
When supplemented by a vhf relay for distribution to delegates, that
module may be added to the basic
situated at Rotherham, the expec- the preprints would be available in a
two
vcos
with
400. This contains
ted coverage of Radio Hallam will single bound volume and, worst
phase lock facility, a vc filter, a vc
be about 660,000 people.
of all, that this volume would be
envelope generator, a modulator 1/r Hallam
presented to all delegates to the
and vca. A separate power supply RADIO HALLAM, the group awarded
convention. It looks as if London's
is available. This couplet would the franchise to operate the local
first convention may, after all,
operate within the framework of an radio service for the Sheffield and Counting pennies
Electronic Rotherham area, started broad- SOME GOOD NEWS for users of give the parent organisation someexisting synthesiser.
Music Laboratories Inc, P.O. Box casting on October 1. In keeping impulse counters; Kynmore, who thing to think about.
H-4, Vernon, Connecticut 06066. with the IBA charter, the investors manufacture a large range of
in the new radio company repre- impulse counters, have lowered
sent a wide range of local interests their oem prices by 25 % for six Swann song
has SIR MICHAEL SWANN, chairman of
including Sheffield Newspapers, models in their range. This
Governors, has
Trident Television, several trade been brought about by rationali- the BBC Board of
Radio Idi
line leading made two important speeches since
CEC, A DIVISION of the Cetec Cor- unions, employers such as Delta sation of the product
expressing conporation of America, has recently Enfield Cables and a host of other to cheaper production costs. Kyn- the general election
future
of the BBC.
the
19
about
Ltd,
cern
Co
Engineering
more
announced the signing of a con- people. Of passing interest is the
at a lunchtract to supply broadcasting equip- board of directors; the youngest Buckingham Street, London WC2. The first was deliveredBroadcasting
eon given by the
ment to the Republic of Uganda. member, managing director and Phone: 01-839 2371.
Press Guild in London on October
Valued at £175,000, the shopping station manager Bill MacDonald,
15. He said that the BBC had said
basket includes broadcast studio is 46; the others, all local digna a long time ago that the present
mixers, disc consoles, tape record- tories, are very much more advanc- Costly Classic
would only keep the
ers and a UK developed solid state ed in years. If a crime is committed A CASSETTE TAPE which promises licence fee
going until the spring
corporation
indistingthat
are
the
mis`performances
The
matrix switching system.
in the Sheffield district,
we are likely to be
1975
'when
of
reel'
Sparta Electronic Corporation, creant stands a good chance of uishable from disc or open
limit of our
another subsidiary of Cetec, is to being brought before the board of must be very expensive. The new around about the
supply much of the equipment Radio Hallam; three out of eight Classic Cassette range from 3M is. borrowing powers'.
The licence fee would have to
The cassettes, which obtain their
which will form the basis of the of the directors are magistrates.
increased, he said, and his perbe
Fe30,/
by
This fact aside, Radio Hallam claimed performance
Ugandan external broadcast serview was that it would be
vice controlled by General Idi promises to be successful under CrO2 dual coating technology, sonal
fee twice that
Amin VC (self awarded). Cetec Bill MacDonald's affable direc- cost £2.16 rrp for the C90 size. At just to have a colour Two pounds
white.
and
for
black
the
reception
for
launching
the
the
North
age
of
operaThe
average
tion.
Inc, 13035 Saticoy Street,
38v.
USA. ting staff is about 28, rather less Classic range, 3M stated that they
California,
Hollywood,
than that of the board of directors.
The personality of the station
embodies the form of Keith Skues,
2NA. programme director, general fac-
will concern itself as much with Phone: 213-875 1900. For the
the creation of music by electron- UK: Computer Equipment Comics as opposed to the creation of pany Ltd, Shaftesbury Street, High
37
NEWS
of the BBC's independence, he
said, although many objections
were raised to it. He thought it was
good value for money, and that
politicians had talked themselves
into thinking that rises in the
licence fee were unpopular. `In
times of high inflation it is likely
to need raising rather frequently.. .
the fee has in fact remained static
for nearly four years and must be
the only thing in Britain that has.'
Speaking of alternative means
of financing he said there were
on each of the fees would make a
significant difference, he said, but
he thought it better that the colour
licence should be increased more.
He quoted Denmark's licence fee
as £42.57 and Holland's as £17,
which he said was one of the lowest
in Europe.
He said that the corporation had
been making economies, `though
you can fiddle around with minor many objections to pay -as
-you economies the only way you can view, though he did
not say what
make major ones is by cutting these were. Advertising
too had
programmes. The sort of thing we objections, one of which that
there
could develop is that we do not fill was not enough
to go round. 'Our
vacant posts, make cuts in hours fear is quite simply
that direct
-that sort of thing'. That would government finance would
slowly,
be the situation if the fee were not perhaps almost imperceptibly,
but
increased.
very surely erode our indepenHe said that direct financing dence.' One has to
be a 'very
might be a great deal less trouble- saintly payer
of the piper not to
some for a government but it would wish to call the
tune, and there are
be a great deal more trouble for very few
saints around. The plain
the BBC: 'As long as you have a fact is that government
is responlicence fee you preserve a degree sible for
what is done with governof independence not so easy to ment money.'
preserve if you are financed directA week later Sir Michael made
ly. One way or another you are
a widely publicised lunchtime
much more potentially subject to speech to BBC
staff. He said that
government intervention.' He was the responsibility for programmes
in favour of index-linking of the must rest
with the people who
licence fee to the cost of living.
make them. Although the goverHis remarks were made off the nors were the
custodians of the
cuff, the BBC say, and a copy of
public interest in broadcasting they
them is not available. However, could
not possibly see and evaluate
for a speech made to the Royal all the 100,000
hours of programTelevision Society in Birmingham, mes the BBC
put
copies were made available to the every year. 'Who,out nationally
I wonder,
press beforehand. In it he express- would indoctrinate the
censors and
ed anxiety that the independence what would this
do to the confiof the BBC might be eroded. Its in- dence and self respect
of the
dependence rested on freedom from programme makers? I shudder
to
government control, which ensured think.'
that listeners trusted what you
The week of the first speech
broadcast, and kept internal editor- ended with a question
about the
ial freedom, avoiding an attach- future of broadcasting
being asked
ment to right or left or to any on 'Any Questions?' but, mercifully
pressure group.
and by the sheerest coincidence,
Speaking of accusations of bias Marghanita Lasky, who is on the
he said that they were not equally
Annan Committee, was on the
balanced between right and left: panel to answer it.
She exhorted
`Instead, when there is a Conservative government the complaints
are mainly of left wing bias, and Sintronic DFM-250-SS
when there is a Labour government of right wing bias.'
If we are being, as we try to be,'
he continued, `scrupulously impartial, it inevitably follows that we
are likely to annoy the party in
power more than the party in
opposition
It has been suggested to me once or twice by civil
servants . . . that the process of
government has now become so
difficult that the media in general
and the BBC in particular while
reporting impartially, should lean,
if only slightly, towards Government
But I am clear that this is
an impossible request.'
The licence fee was a guarantee
38
STUDIO SOUND, JANUARY 1975
...
...
listeners to write to the committee
telling them what they thought
on the subject. Lord Windlesham
has also said his piece on the
independence of the BBC. This
spontaneous burst of loyalty to
the corporation may be not unconnected with the fact that the Annan
committee takes its last evidence
at the end of the year, only a few
weeks away. More of the kind
may be expected.
House of Lords, has joined ATV
as a full time joint managing director. The other joint managing
director is Mr Bruce Gyngell, formerly deputy managing director of
ATV Network Ltd, and now also
deputy chairman of ATV.
Lord Windlesham, who joined
ATV in November after announcing his decision following the
Conservative defeat during the
election, made a speech just after
his announcement praising the
BBC for having established an
independent system of broadcasting in this country: 'All broadcasters should be concerned about
the principle of independence, and
any new arrangements for financing
the BBC should be made only after
a period of very thorough scrutiny
by an all party independent committee.'
New premises for expansion
ELECTRONICS, the mixing
console manufacturers, have moved
to larger premises situated at Brow ells Lane, Feltham, Middlesex
TW13 7ER. The new phone
number is 01-890 0087/8/9. By
way of a welcome, Helios recently
received an order for three broadLord Windlesham joined
cast consoles to be delivered to
Mainos tv, part of the Finnish Associated Rediffusion in 1957
where he was an executive producer
broadcasting network.
on documentaries. He was made a
director in 1965. In 1967 he joined
Grampian where he was managing
Solid state 250W fm
director and controller of progtransmitter
rammes until 1970, when he joined
AVAILABLE IN TABLE TOP format, the Heath government
as Minister
the DFM-250-SS fm power ampli- of State at the Home Office. In
fier from Sintronic develops a 1972 he moved to the Northern
claimed 250W from completely Ireland office. He became leader
solid state circuitry. The unit is of the Conservative peers in June
said to meet the relevant CCIR and 1973, having served on Westminster
FFC standards for broadcast trans- City Council from 1958 to 1962.
mitters when used with a low He delivered a Granada Guildhall
power exciter/driver. The manufac- lecture in 1974 on politics and
turers recommend their own DFM- broadcasting.
10 unit for use with the amplifier.
Intended for fm use only, amplifier
operates under class C conditions Low cost open headphones
at a constant power level and duty BEYER DYNAMIC HAVE recently introcycle. Broadcast/Communications duced a low cost open headphone
Division, Singer Products Com- onto the British market. Although
pany Inc, One World Trade Center, the phones look very flimsy (which
Suite 2365, New York, NY 10048, also implies that they are very
USA.
light), they are claimed to be very
tough and capable or taking much
abuse. A very brief listening test
indicated that the sound quality
Windlesham
LORD WINDLESHAM, 42, leader of was much higher than the £7.83
the Conservative opposition in the price tag would suggest. On the
subject of microphone stands,
Beyer said that they intended to
import the Konig and Meyer range
from West Germany. Beyer Dynamic (UK) Ltd, 1 Clair Road, Haywards Heath, Sussex. Phone: 0444HELIOS
51003.
Direct drive turntable unit
pole direct drive
dc servomotor, the SR717 turntable
from Sansui is claimed to provide
POWERED BY A 20
`state-of-the-art' performance. The
quoted short term speed stability
is 0.035 % with a rumble figure
better than -60 dB. The tone arm
is also new; it is fitted integrally
with the turntable and is said to
do all the things that a good tone
arm is supposed to do. Other
features include a built-in strobe
with fine speed adjuster, a direct
reading stylus pressure gauge and
a plinth which was specially
designed to damp out resonances.
The price is £222.44. Sansui Audio
Europe SA, 39/41 Maple Street,
London W1P 5FU. Phone: 01-580
5352.
AIR
OVER FOUR MONTHS after
Chrysalis announced they had
taken over Wessex recording
studios comes the news that they
have purchased AIR studios and
all its associated companies for a
total purchase price of around £1
million. Chrysalis have obtained a
majority shareholding in AIR with
an option to buy the rest of the
shares within five years, though it
may not take that long.
At the beginning of August AIR
nearly completed a deal with DJM
but a last minute hitch developed
and prevented the deal going
through. It was widely supposed
in the industry that George Martin
would continue to try to find a
buyer for AIR and that he was
interested in setting up a floating
studio on a yacht.
Chrysalis say their pre-tax profits
this year will be £1,500,000. They
now own six multi -track recording
studios and they say this makes
them one of the biggest studio
groups in the world.
JUST
Cassette tape
CLAIMED TO POSSESS
a performance
equal to chromium dioxide formulations, the new ferric oxide X1000
cassette from EMI costs only 99p
(C60). EMI state that the frequency response extends from
25 Hz to 15 kHz without giving the
recording level at which this figure
was obtained. EMI, Blyth Road,
Hayes, Middlesex. Phone: 01-573
3888.
Tandberg instrumentation
recorder
THE AGENCY DIVISION of Farnell
Instruments has announced the
availability of Tandberg's new four
channel fm carrier tape recorder
model TIR 115. This is a lightweight
portable recorder using 6.25 mm
tape at speeds of 2.37, 9.5 and 38
cm/s.The frequency response is from
dc to 5 kHz at the highest speed.
A crt monitor displays the carrier
deviation of all four channels
simultaneously; in addition, one
channel may be used for vocal
comments. Farnell Instruments
Ltd, Sandbeck Way, Wetherby,
Yorkshire LS22 4DH. Phone:
0937-3541/6.
Independent Local Radio
local radio
stations have taken to the air:
Swansea Sound, who started regular broadcasting on September 30,
and Radio City who likewise commenced on October 21. Swansea
Sound (managing director Charles
Braham) fields a board of directors
whose makeup is best described as
obscure; this may well reflect the
local nature and integrity of the
station.
Radio City, which broadcasts to
the Liverpool area, is made up of
enterprising scouses such as Ken
TWO MORE INDEPENDENT
Dodd and Carla Lane under the
managing directorship of Terence
Smith, a well-known journalist.
court ruled that RAI's monopoly
of radio and television was illegal.
The state had no right to ban cable
television and private relay stations
beaming foreign television services
into Italy. Such a state monopoly
could be constitutional only if it
guaranteed free, impartial and representative information. `These are
now lacking,' they said. The Italian
government had banned cable
television in 1973 and the decision
contributed to the downfall of the
coalition government led by the
Christian Democrats under Signor
Andreotti. In June this year the
dismantling of private relay stations
beaming programmes from Switzerland and Austria was ordered
but Telebiella, a Turin cable television company, appealed against
the decision, and others followed
suit. During the recent campaign
for a referendum on divorce the
RAI service was accused of bias.
US standard for amplifiers
of a recent ruling by
the US Federal Trade Commission,
power output ratings claimed for
amplifiers used in domestic and
in -car entertainment products must
now conform to a fixed format. RIAA equaliser
The new regulation, effective Nov- DESIGNED FOR BROADCASTING, the
ember 4, requires the output rating Stereo Disc Amplifier from Surrey
to be given in rms watts per Electronics provides amplification,
channel, both channels driven, equalisation and filtering of signals
AS A RESULT
together with the corresponding from magnetic pickup cartridges.
frequency response, load impe- The unit is claimed to meet the full
dance and total harmonic distor- IBA specification for disc preamp
tion specified at that rating.
equipment; the quoted noise figures
are -58 dB referenced to 6 mV
input to produce an output level
RAI
of 0 dBm. The 18 dB/octave filters
and
Italian
Radio
HEAD
OF
THE
corner at 24 Hz and 10 kHz; the
Television, Signor Ettore Bernabei, low pass circuit is switchable on
has resigned. The news that he the front panel for surface noise
would do so was leaked by the
reduction. The unit is self powered
company he is to join, Italstat, a from standard ac lines through an
construction firm, only days before XM connector with the whole
journalists, politicians, writers and assembly mounted in a rigid diecivil rights campaigners were to cast box. Signal lines connect via
march on RAI Headquarters on lockable DIN sockets.
September 20. We understand from
Already in service with several
RAI's office in London that he ilr stations, the Stereo Disc Ampliwould continue in office as general fier is available ex -stock from
manager until the organisation's Surrey Electronics, The Forge,
charter expires on November 30, Lucks Green, Cranleigh, Surrey
1974.
GU6 7BG. Phone: 04866 5997.
The London office of RAI would
make no comment on the reasons
for Bernabei's unpopularity and
would make no statement on Console for radio and tv
reports that he used autocratic and INTENDED MAINLY for tv broadcast
unorthodox methods, or that he use, the new 16 input Robins/Fairused the state radio and television child mixing console claims to be
service as a source of political pat- suitable for radio applications.
is op
ronage and nepotism, or that he Construction is modular
ran up huge deficits. He was said amps are used throughout-proto have encouraged political con- viding the possibility of further
trol of the RAI's output, control- system expansion at a later date.
ling news and documentary prog- Standard features of the model
rammes so that social problems 1632 are two output channels for
would be glossed over but poli- separate studio and control room
ticians' activities would be covered monitoring, c/w muting relays, a
in full. Little coverage would be headphone output from the control
given to political scandals, riots or room monitor, a cue channel with
built-in speaker, talkback facilities
the soaring cost of living.
The close of November marked for two studios etc, wire -wound
the end of a troubled period for faders and illuminated push button
RAI. In July Italy's constitutional switching. There is a range of pro-
-
cessing modules (compressors,
equalisers etc) available for use
with the desk. The basic unit costs
$9,995. Robins/Fairchild, 75 Austin
Blvd, Commack, Long Island,
NY 11725 USA. Phone: 516-543
5200.
PCB mounting frames
to manufacturers of modular pcb systems, the
Scanbe mounting assemblies offer
a complete card stacking file for
standard or wire wrap cards.
Standard card guides are 15 cm
long, arranged in 43 cm rows at
1.2 cm spacings holding up to 34
cards per file. Sold as a complete
unit, connector mounting bars,
end plates and full assembly
instructions are included. Tekdata
(Trading) Ltd, Westport Lake,
Canal Lane, Tunstall, Stoke on
Trent, Staffs ST6 4PA. Phone:
OF SPECIAL INTEREST
0732-811711.
Indian horns
manufacturers of cinema sound and pa
equipment, has received an order
for 300 S3 pressure units to be
delivered to a major Indian sound
reinforcement company. This is
the largest Indian order ever
received by Vitavox; the company
claims that this represents a major
breakthrough for loudspeaker marketing in India. Vitavox Ltd, Westmoreland Road, London NW9
9RJ. Phone: 01-204 4234.
VITAVOX, WELL KNOWN
Dekko
DEKKO FILMS AND
Dekko Sound
services of Boston, Mass, have
moved to a new studio designed by
the acoustical engineering firm of
Bolt, Beranek and Newman situated at 295 Huntington Ave. In
the finest traditions of our colonial
cousins, the new studio is described
as `floating, soundproof, acoustically correct and perfectly isolated'.
Dekko equipped the studio with a
Magnatech sound system offering
full editing facilities, and with
audio visual dubbing equipment
capable of working directly with
magnetic film soundtracks. Small
run cassette duplication is also
offered. Dekko Films Inc, 295
Huntington Ave, Boston, MA.
02115. USA. Phone: 617-536 6160.
New QS decoder
USING CUSTOM IC chips, the QSD 1
QS Variomatrix decoder from
Sansui is said to offer a similar
standard of performance to the
professional QSD 4 model at a
much reduced cost. The new
decoder claims a wide dynamic
range, a high degree of interchannel
40
39
NEWS
separation and a creditable 0.05
distortion. In addition, the unit
provides `hall' and `surround' synthesised effects.
Heart of the unit is a series of
integrated circuits developed for
Sansui by the Hitachi Corporation.
The first of the series (HA1327)
constitutes the phase discriminator;
the second (HA1328) is the matrix
with the third (HD3103P) being an
fet array providing control. At the
present, the chips are available in
sample quantities to original equipment manufacturers from the following Hitachi offices: Hitachi
America Ltd, Chicago Office, 111
East Wacker Drive, Chicago, Illinois 60601, USA. Phone: 312-644
6565. Europe: Hitachi Ltd, 4
Dusseldorf, Immermann Strasse
15, West Germany. Phone: 0211351185.
Chipping Norton Studios
STEPPING OUT OF the railway carriage at Kingham station, the first
length to breadth ratio about two
to one, slightly unusual but entirely
satisfactory from an operating
point of view.
The longest wall runs parallel
to the control room having a large
window let into the same wall to
enable a wide view of the floor.
When asked about traffic noise from
lorries grinding up the steep hill
outside the building, Dave Grinstead pointed out that they don't
make schools like this one anymore. Indeed, the walls are reminiscent of a medieval keep in their
thickness; mineral fibre blocks
exclude any residual noise; walls
and ceiling are lined with this dense,
fireproof material. As expected,
the floor is of solid concrete construction. At one end of the room
resides a Yamaha grand piano, at
the other a large drum booth with
the greater part of a spare drum
kit stowed on the roof.
Mastering arrangements are
handled by two Scully quarter-inch
tape machines; the MCI multitrack master operates from the
control desk through 16 Dolby
A361 noise reduction units leaving
an extra four in reserve for mastering. Other control room fixtures
include an AKG floor standing
reverb unit, an EMT stereo echo
plate and Universal Audio compressor/limiters. The layout of the
control console seems well thought
out with the most frequently used
controls within easy reach of the
operator, this was borne out by
watching the techniques during a
recording session. Richard Vernon's
sounds heard emanated from chickens pecking about on the platform;
the rural ride to the village of
Chipping Norton, deep in the
heart of Oxfordshire, was nearly
over. A four mile taxi ride in a
mud splattered motorcar completed the journey. One glance at
the exterior of Chipping Norton
Studios indicates that the building
was once the village school complete with bell to exhort its pupils
to lessons.
The iconoclasts that built the
studio from the former seat of
parochial learning are Mike and
Richard Vernon, record producer
and finance man respectively. Mike,
who created one of the first progressive record companies in the
'Blue Horizon' record label, doesn't
take part in the day to day running of the studio; although he
produces most of his records at
Chipping Norton, he leaves it to
Dave Grinstead et al to keep the
tape spools turning. Dave, who
started his chosen career as a tape
operator with Decca, looks after
the technical aspects of studio life,
sharing the session balancing work
with Barry Hammond.
Chipping Norton Studio is 16
track; the MCI recorder is fed from
a 18 input Trident `B' series desk
which, according to Dave, will
soon be changed for a quad -wired
24 input 'A' series console. A pair
of Quad powered JBLs provide
monitoring in the compact control
room which appears to give very
acceptable acoustic properties with
regard to unwanted resonances
etc. The rectangular studio has
40
STUDIO SOUND, JANUARY 1975
young offspring, present in the
control room at this time, proved
that the acoustic isolation between
this room and the studio left
nothing to be desired.
One of the best and most imaginative features in this rustic setting
is the relaxation and accommodation facilities afforded to visiting
clients. The upstairs classrooms
have been converted into a selfcontained flat of spacious proportions. The studio provides a
communal lounge and cooking
areas together with separate bedrooms housing up to 14 bodies in
very comfortable surroundings.
Dave Grinstead, appropriately,
lives in the erstwhile headmaster's
house next door to the studio. The
village of Chipping Norton offers
all the benefits of rural life; this
includes a first rate public house
serving genuine bitter straight
from the wood. The village seems
the perfect backdrop to a very
happy recording studio.
Portable Dolby
with the Nagra
IV, the DNR series of portable
noise reduction units from Future
Film Developments can be adapted
to operate with other machines.
The Dolby processor is based on
'A' type noise reduction modules
cat. no. 22 which are activated
DESIGNED FOR USE
Far top: The converted school house at Chipping Norton.
Above: Milk proof mixers for same.
58
raises the standard
quality Tape Duplication
inCâUSS
Used by every major duplicating
company. Gauss, with installations in
ARGENTINA
AUSTRALIA
CANADA
ENGLAND
FRANCE
GERMANY
GREECE
ITALY
JAPAN
MALASIA
MEXICO
NETHERLANDS
NORWAY
SWEDEN
SWITZERLAND
UNITED STATES
has led the industry since the
inception of pre-recorded tape.
Now, with the introduction of the
exclusive, patented "Focused Gap"
Ferrite head, Gauss has raised the standard
even higher. Retaining the high penetration,
low noise and low drop out characteristics
of the "Focused Gap" design, the new heads
provide wider frequency response and significantly extended head life. Add to this
Gauss' exclusive pneumatically driven
horizontal loop bin, 20 slave system capacity
with stagger loading capability, new easy
4 track/8 track conversion, 32:1 duplicating
speed, traditional precise tape handling and
you have the ultimate in quality at the world's
highest production rate.
For your best buy in ultra high speed
tape duplication, insist on Gauss, "The
another fine
Standard of the World,"
product of Cetec.
A basic Series 1200 system (Master Reproducer,
Loop Bin, and Slave Recorder).
CteclNC.
a subsidiary of Computer Equipment Corp.
13035 Saticoy St., N.Hollywood, California, (213) 875-1900 TWX 9104992669
EUROPEAN OFFICE
Cetec (U.K. Ltd.)
16
Uxbridge Road, Ealing, London W5 2BP.
Tel. 01-579 9145.
Telex: 935847
VAIrar K
THE FOLLOWING list of Complete Specifications Accepted is quoted from the weekly
Official Journal (Patents). Copies of specifications may be purchased (50p) from the Patent
Office, Orpington, Kent BR5 3RD.
October 2
1374179 Sony Corporation.
Magnetic tape recording and/or reproducing
apparatus.
1374224 Eastman Kodak Co.
Cartridges for strip material.
1374234 Olympus Optical Co Ltd.
Electrical attachment devices.
1374293 Sony Corporation.
Video signal reproducing systems.
1374309 Pioneer Electronic Corporation.
Protective circuit.
1374456 Hitachi Ltd.
Post deflection focusing type colour cathode
ray tube.
1374502 RCA Corporation.
Method of radio frequency splutter etching.
1374521 Crosfield Electronics Ltd.
Image reproducing methods and apparatus.
1374539 Nippon Gakki Seizo KK.
Tone-source device.
1374540 Philips Electronic & Associated
Industries Ltd.
Automatic gain control.
1374560 Tokyo Keiki, KK.
Slot array antenna with flare.
1374567 Telefonaktiebolaget L. M. Ericsson.
Double reflector antenna arrangement.
1374571 Ricoh, KK.
Testing of recording and reproducing equipment.
1374580 Smiths Industries Ltd.
Electrically -operated display devices.
1374624 Agence Nationale De Valorisation
de la Recherche.
Electrical filters enabling independent control
of resonance or transition frequency and of
band-pass especially for speech synthesisers.
1374674 Sony Corporation.
White balance control system.
1374731 Pioneer Electronic Corporation.
Tape player.
1374735 ITT Creed Ltd.
Telegraph transmission apparatus.
1374741 Saint-Gobain Industries.
Window pane having a radio antenna.
1374974 Agfa-Gevaert.
Device for recording images.
October 9
1375060 Coulter Electronics Ltd.
System for displaying a data distribution curve
on a 100 % scale irrespective of the quantity of
data sampled.
1375176 Defence, Secretary of State for.
Semiconductor devices.
1375223 Rockwell International Corporation.
System for composition of symbols.
1375240 Eastman Kodak Co.
Motion picture cartridges.
42
STUDIO SOUND, JANUARY 1975
Nippon Gakki Seizo KK.
Musical instruments.
1375388 General Electric Co.
Projection systems.
1375526 Felten & Guilleaume Kablewerke Ag.
Capacitor equalising box for balanced low frequency communication cables.
1375604 Decca Ltd.
Correction of instability in film projection.
1375618 Burroughs Corporation.
Line Generator for CRT display system.
1375638 Western Electric Co Inc.
Electromagnetic wave frequency conversion
1375353
devices.
1375645 Rank Organisation Ltd.
Television picture correction.
1375664 International Business
Machines
Corporation.
Transversal filter equaliser.
1375680 International Standard Electric Corporation.
Antenna array arrangements.
1375782 Sansui Electric Co Ltd.
Signal transmission system.
October 16
1375906 Sumitomo Electric Industries Ltd.
Radomes.
1375919 Viennatone Horgerate Produktions
GMBH.
Telephones.
Bosch Fernsehanlagen GMBH.
Television apparatus.
1376006 Arvin Industries Inc.
Magnetic disc -type recording mechanisms.
1376046 Siemens AG.
Radio receiving antenna systems.
1376059 Philips Electronic & Associated
Industries Ltd.
Amplifier circuit.
1376072 Knight, B. E.
Instruments of the guitar family.
1376083 Hofmann, U.
Circuit arrangement for recording binary
signals on magnetisable storage media.
1376093 Matsushita Electric Industrial Co
Ltd.
Sampling modulation system for an electronic
musical instrument.
1376100 International Business Machines
1375925
Corporation.
Magnetic recording heads.
1376125 Southern Communications Ltd.
Tape recording and/or replaying apparatus.
1376128 Plessey Co Ltd.
Systems for monitoring mains electrical power
supplies.
1376158 Hitachi Ltd.
Pattern generating device and method of
recording a generated pattern.
1376189 Xerox Corporation.
Mask for facsimile scanning apparatus.
1376220 Matsushita Electric Industrial Co
Ltd.
Cathode ray tube having index strip electrode.
1376260 Omron Tateishi Electronics Co.
Magnetic memory unit.
1376296 RCA Corporation.
Secam decoder.
1376335 Agence Nationale De Valorisation
De La Recherche.
Electrostatic transducers for converting electrical signals into ultrasonic signals and vice versa.
1376357 Thomson-CSF.
Method of telecommunication via satellite and
systems using this method.
1376358 Wagner Electric Corporation.
Induction -keyed control circuit with keying
network having variable resonant frequency.
1376371 Eastman Kodak Co.
Apparatus for directing strip material from a
roll.
1376414 Standard Telephones & Cables Ltd.
Electro acoustic -transducers.
1376433 Absalom, R. R.
Electric sound -producing device.
1376441 Kodak Ltd.
Cinematographic film.
1376455 Brown, S. G., Communications Ltd.
Telecommunications headsets.
1376465 Matsushita Electric Industrial Co
Ltd.
Colour image pick-up system using strip filter.
1376517 Price, E. E.
Electro -optical display system.
1376548 Bosch Fernsehanlagen GmbH,
Robert.
Voltage reduction circuit.
October 23
1376611 Tricoire, J.
Thermographie sheet.
1376616 Seneca Plastics Ltd.
Optical display system.
1376651 Mullard Ltd.
Device for generating sound waves.
1376652 International Computers Ltd.
Magnetic transducers and to methods of
manufacture thereof.
1376670 Luxor Industri AB.
Driving mechanism for the turntable of record
players.
1376707 Matsushita Electric Industrial Co
Ltd.
Record apparatus.
1376757 General Electric Co.
Stereophonic decoder circuit arrangements.
1376799 Philips Electronic & Associated
Industries Ltd.
Image display cell.
1376832 Philips Electronic & Associated
Industries Ltd.
Electro -acoustic transducer.
1376907 Western Electric Co Inc.
Single tube colour cameras.
1376954 Philips Electronic & Associated
Industries Ltd.
Line amplifier.
1376984 International Computers Ltd.
Magnetic circuits.
1377021 Philips Electronic & Associated
Industries Ltd.
Signal receiver for receiving signals of different
frequency.
44
AKG have a new electronic
Time Delay Unit TDU 7202.
These units will be demonstrated throughout the
country, early 1975. Ring
AKG for details and in the
meantime a booklet is
available on request.
We don't know too much
about all this gear really,
but, we do give you all the
literature at Exhibitions
and we are such a success
I wonder why*?
See you at the AKG stand;
AES Convention, APAE
Exhibition, and APRS
Exhibition.
*Because they are wise and
sweet and have such
such big ears. Peter Eardley.
Their versatile C45I is a
winner and ever so popular
on Television.
AKG now have a range of
ELECTRET Microphones
including the NEW CE.10
miniature Lavalier.
QUIPMENT LTD
182 CAMPDEN HILL ROAD
LINIME3 7A5. 01.229.3695.
Y
43
PATENTS
Polaroid Corporation.
Motion -picture film cassettes.
1377080 Matsushita Electric Industrial Co
Ltd.
Stereophonic reproducing system.
1377108 Pioneer Electronic Corporation.
Endless tape cartridges.
1377138 Matsushita Electric Industrial Co
Ltd.
Four channel arrangements.
1377178 Hanlon, T. F.
Apparatus for reproducing a colour image
from colour image information coded on black
and white film.
1377237 Standard Telephones & Cables Ltd.
Telephone headset.
1377262 Sperry Rand Corporation.
Communication systems.
1377263 Sperry Rand Corporation.
1377033
Pulse receivers.
1377334 Bendix Corporation.
Communication system with at least one
repeater station using the same carrier
frequency.
1377351 Victor Co of Japan Ltd.
Miniature tape cartridges.
Video recording of still pictures
I READ BP1,349,665 from Matsushita Electric
Plessey Co Ltd.
Apparatus for processing electrical pulses in
TDM systems.
1377378 Pioneer Electronic Corporation.
Record -changer spindle.
1377374
October 30
1377426 Messerschmitt Bolkow Blohm GmbH.
Method of and apparatus for photographing a
subject by line scanning.
1377447 RCA Corporation.
Apparatus for replicating magnetic recordings.
1377531 Varian Associates.
Network for pulling a microwave generator to
the frequency of its resonant load.
1377543 Sony Corporation.
Decoding systems for colour television receivers.
1377583 British Aircraft Corporation Ltd.
Communication systems.
1377670 Compagnie Honeywell Bull.
Disc memory units.
1377684 Telecommunications Radioelectriques
Et Telephoniques.
Data -transmission filter.
1377770 Sato, S.
Apparatus for visual projection and sound
reproduction.
1377792 International Computers Ltd.
Cathodochromic information display.
FIG. 2
1377796 Singer Co.
Synchronised film transport electronics for
telecine systems.
1377814 Bachmann, M. E.
Transcription control for cassette tape player
or the like.
1377858 Telemation Inc.
Colour television encoder modulator.
1377870 Matsushita Electric Industrial Co
Ltd.
Rotary head type magnetic recording and
reproducing apparatus.
1377871 Ricoh, KK.
Magnetic recording and reproducing arrangements.
1377884 Ricoh, KK.
Magnetic recording and reproducing arrangements.
1378019 Singer Co.
Display for video information.
1378035 Siemens AG and Telefonbau and
Normalzeit GmbH.
Transmission of asynchronous information in
a synchronous serial time division multiplex.
1378036 Peak Technologies Ltd.
Microwave radiation monitor.
1378114 Nippon Electric Co Ltd.
Antenna system.
22
Industrial Company Ltd of Osaka as directed
particularly towards the use of tv systems to
communicate photographs, data read-outs and
perhaps newspaper pages in permanent form.
According to the inventors, attempts to take a
permanent record of a video image are complicated by the fact that the image is produced
by a flying spot.
The invention takes the form of a normal
tv set with conventional circuitry, display tube
and controls; but a secondary, slave tube, with
a fibre optics face plate is also used, the inner
surface of the face plate being coated with a
phosphor. This slave tube is housed out of
sight within the set but is under the influence
of all the normal set controls. Thus the picture
on the slave tube should match the picture on
the main display tube.
As shown in fig. 2 the slave tube 25 directs
an electron beam on to the inner surface of
FIG. t
face plate 26 and a recording medium 21 (such
as film) is pressed by pressure pad 46 against
the plate 26. Thus the film is exposed to radiation emitted from the video image to record a
desired single frame. The film 21 is fed to the
slave tube for exposure from a store roll 31,
and after exposure is passed through a processor 36. The film with the processed image is
turned through 90° at 44 and fed out through
44
STUDIO SOUND, JANUARY 1975
a letter -box slot in the front of the set.
Synchronisation between the feed rate of the
film 21 and the sweep rate of the flying spot
on the face plate 26 is unnecessary because the
film is fixed by the pressure pad during the
recording operation. Fig. 1 shows the set as
seen by an operator, with the main display
tube at 13 and the developed film 21 emerging
from the slot 19.
Quadraphonic loudspeakers
SO FAR EMI Ltd have been issuing quadraphonic records made in the CBS SQ system,
and there has been no sign of any independent
EMI activity on the surround sound front.
BP1,348,643 from EMI still doesn't show
whether the company have any home-grown
matrix system up their sleeve, but discloses
their interest in a quite new approach to
providing sum and difference pseudo-quadraphonic surround sound.
An ordinary stereo amplifier is used to
reproduce two -channel recordings. As is now
well known, conventional stereo recordings,
and matrix recordings in particular, contain
additional information which is there for the
taking. Such additional information is usually
extracted by phase shift or resistance networks
at the amplifier, but the EMI proposal is that
the loudspeakers themselves be used to decode
the information. This they achieve by providing each loudspeaker with two drive coils each
operating on the same diaphragm but having
different numbers of turns.
In fig. 1 the lefthand channel output terminals 15, 16 feed series connected coils 10, 6, 12
8 of loudspeakers three, one, four and
two (arranged as shown in fig. 1) and the
righthand channel output terminals 13, 14
feed series connected coils 9, 5, 11 and 7 of the
same loudspeakers. The two coils of each
speaker are wound in different senses and/or
have different numbers of turns. Thus, the
front right loudspeaker one has its coils 5 and
6 acting on the diaphragm in additive sense,
as do coils 11 and 12 of front left loudspeaker
four. Rear right loudspeaker two has coil 8
in subtractive sense with respect to its coil 7
and rear left loudspeaker three has coil 9 in
subtractive sense with respect to coil 10.
EMI suggest that the output signal voltage
from the right channel should be distributed
between coils 5 and 9 in the proportions .707
and .293 and in similar proportion between the
coils 7 and 11. Likewise the output from the
left channel is distributed between coils 10 and
6 and between coils 12 and 8, also in the
proportions of .707 and .293. These proportions are best attained by using coil turns in
the ratio 2.4 to 1. This arrangement means
that the signals applied to the loudspeakers
are as follows:
Loudspeaker one (right front) .707R+.293L
=R +0.41L
Loudspeaker two (right rear) .707R-.293L
FIG.
Loudspeaker three (left rear) .707L-.293R
and
=R-.41L
1
3
4
1
I
f0
i
15
6
I
16
I
i
12777
=L-.41R
Z
lyf
i
i
Loudspeaker four (left front) .707L+.293R
Ii
B
b
I
Ì
i
4111
!
L5
!
I
14
;
11
J
7
,
Aquatic loudspeakers
THE RANK Organisation in BP1,348,535
proposes some extremely interesting ideas on
loudspeaker cabinet damping. As is well
known, a light cabinet suffers from panel
resonances which may colour the loudspeaker
tone; brick or concrete cabinets are free from
such resonance but are often impractical. The
Rank patent claims that loudspeaker cabinets
of which the walls are formed from liquid -filled
containers offer the best of both worlds.
A loudspeaker cabinet is built as a skeleton
frame rather like a fish tank without glass. The
side, rear, top and bottom panels are all liquid filled double -walled containers which can be
slotted into the skeleton. While the panels are
empty the cabinet is relatively light and portable. When the panels are filled it is very
AGONY COLUMN
The American record producer would insist
on having his little joke at the expense of his
protégés. Of note was one occasion where he
persuaded a well-known Anglo-Saxon drummer
that his Yank counterparts got 'a nice bass
drum sound' by overdubbing a separate track
of the bass drum played by kneeling down and
hitting it with boxing-gloved hands. Dutifully,
at the next session the enlightened drummer
turned up sporting a pair of boxing gloves.
Polite laughter was heard in the control room
as he spent the next three takes grovelling on
the floor smashing the bass drum before
realising that he had been had.
IN
=L+.41R
Although the signal addition and subtraction
is usually achieved by winding the coils of
different turns in different directions, the same
effect can of course be achieved by winding
the coils in similar directions and connecting
them in opposite senses.
heavy. The filling liquid can be water (with
anti -freeze to prevent rupture in the winter) or
any other liquid that proves suitable.
It is maintained that liquid -filled panels
have a very high sound -damping factor and
thus in many ways behave acoustically as
concrete or brick structures. The presence of
water inside a loudspeaker cabinet also provides a convenient on -the -spot means of cooling the voice coil jacket. In fig. 1 loudspeaker
two is connected by conduits 6 to a water -filled
rear wall 3 of the cabinet 1.
All this prompts me to wonder what results
would be obtained from an infinite baffle -type
loudspeaker virtually filled with liquid as an
acoustically damping medium (with of course
some insulation to protect the diaphragm and
speech coil).
Adrian Hope
A well-known fuhrer of studios and record
companies is alleged to exhibit legendary
meanness towards his underlings. It is also
said that he seems to be badly informed about
matters musical and electronic. Driven to
desperate measures, an impoverished engineer
offered the latter-day Scrooge a tape recorder
for sale that was his only worldly possession,
saying that the purchase of the instrument
would do wonders for the fuhrer's turnover.
Of course, the machine went back home with
the engineer the moment that the cheque was
received. In due course, the engineer became
impecunious once more. This time, our friend
went to the great man and suggested that if
he had two machines, the studio could do
great things in stereo
`another' machine
was purchased.
...
The session was going quite well, despite
the big line up. There was a fairly aimiable
atmosphere anyway, but the bar helped, and
lunchtime had taken its toll. Due to the
arrangement of the studio, the percussionist
was forced to play his gong over his shoulder,
so that he could watch the conductor's waving
and hit it at the appropriate moment. Unfortunately, he missed the conductor's relatively
subtle indications to play more quietly, and
didn't look like responding in the immediate
future, so the fixer crept discreetly round
behind him to tell him. In the meantime, the
musician had swayed rather more than was
good for his playing; consequently, when the
next stroke was played, it was just as loud as
before except that it was the fixer's face that
made the sound.
45
tI min 3
Di al
Going solo: There must be a strong motivation
for a man to forsake the comforts of PAYE,
pension contributions, sick pay, entitlement to
Unemployment Benefit, paid holidays and all
the little luxuries a good employer should
provide, to go on his tod as an independent
contractor. But there is a growing trend for
recording engineers to do just that, to go 'free-
lance'. What personal advantages can there
be in adopting such a course? It is said that to
be self-employed can offer a modicum of relief
from the burden of income Tax. Acceptable
claims can be made for items of expenditure
which would not be allowed to someone In
regular employment.
An eminent record
producer once boasted that his friendly local
Tax Inspector passed a claim for the cost of
exotic deodorants made on the grounds of
essential use in the hot, stuffy atmosphere of
control rooms. Be that as it may, it doesn't
seem really credible that intelligent, sober,
level-headed fellows like recording engineers
would jack in good jobs for the sake of a bottle
of tax-deductible after-shave. Surely there
must be something more to it than that. After
all, that 'Tax advantage' thing is a bit insubstantial. Admittedly it can be proved that, by not
having to pay tax on the earnings of Year 1
until some time in Year 2, or later if the pace
of the exchange of query letters can be kept
up, then advantage is taken both of the
depreciation of the value of the currency during
the period and the interest on the money
remaining in the bank during that time, that
interest itself being subject to tax but at a still
more remote time. There are those who make
a hobby of that sort of thing and jolly good
luck to them, but unless one is earning an
enormous amount of money it hardly seems
worth all the bother. Recording engineers do
not, on the whole, earn enormous amounts of
money. If they really are in full command of
all the skills they should have, then their
contribution to a successful recording is often
grossly under -priced. Can that be the reason
for engineers going free-lance? Whatever the
reason, it is an interesting trend of some
significance when taken in context with a
parallel development in the success of the
ACTT's recent recruiting drive among recording studio staff, until now traditionally non Union. When a gap appears between management and worker, the Union is always there to
fill it with, perhaps, some of the workers who
have gone free-lance.
Stands and speakers: Very good to hear in all
the gloom depressing the audio market that
Tannoy and Keith Monks Audio have come
back from the Tokyo Trade Fair clutching
some really juicy orders won against heavy
competition. If the goods/quality/time/price
ratio is right and a high level of customer
service is offered, then business can still be
done by those making the effort.
46
STUDIO SOUND, JANUARY 1975
m
Revelation: Remember the shock sensation
story of the bugging of Transport House
around last election time? There was this van
bristling with `aerials' parked in Smith Square,
see, and this guy, nosier than most, creeps up
to the back and presses his face against the
window to glimpse another guy, inside the van,
crouched over some apparatus and wearing a
pair of cans. Inside guy spots nosey outside,
appears to panic, and the van takes off in a
cloud of dust and old manifestos. Instant
conclusion jumped at with the speed of an
Olympic hurdler-guy with the cans has been
listening in on secret 'phone calls subtly coded
like 'Keep it warm, luv. I shall be home late'
or `Is that you, Solly? What are the odds?' to
be relayed to SMERSH. Nonsense, nothing of
the kind. The simple truth is that the guys in
the van had been doing a bit of crafty pirate-ing
on a recording being made at St. John's, Smith
Square, and thought the face at the window
belonged to BPI's special investigator who has
become the terror of the bootleggers over the
past 12 months. Anyway, that's the story,
brothers, and every bit as believable as the
original. Seriously though, the BPI has been
having considerable success in reducing the
incidence of pirate-ing and bootlegging, and a
number of people have found themselves on
the wrong end of an expensive prosecution. It
is not the sort of thing an honest, hard working
studio should get itself involved with.
What are the wild waves saying?: Bother in
the air again! The frequencies are getting
overcrowded. And now, horror of horrors,
listeners in Tirana are being denied Tony
Blackburn's jokes (they should be so lucky !)
because BBC Radio One is on 247 metres
which is precisely the same wavelength as
Albania's capital city. 1948 saw the last
handout of wavelengths with the UK and
France getting the best choice. Germany was
left with that new VHF system rather on a
let 'em have it, it won't last' philosophy.
Since then radio has grown both in numbers
of stations and in radiated power. A number
of `emergent' nations use radio for propaganda
(so what's new?) and if they find a station
already on their self-chosen wavelength causing
interference, then the policy seems to be to
push up the power by a few Kw's. If everyone
would be content with VHF and with AM at
reasonable power which didn't annoy the
neighbours all would be well, but when national
prestige is at stake, patient reasonableness
becomes a scarce commodity. Attempts to sort
out the confusion are being made by the
members of the European Broadcasting Area
meeting in Geneva. One fairly certain outcome
seems to be that the UK will have to surrender
some medium wave AM channels. Trouble is
that our VHF channels are already rather
crowded with public services, like the police,
ambulance, fire, refuse collectors, and all sorts
by Cross Patch
of unidentifiable people. Never mind, the
changeover, if and when it comes, could give
a much-needed boost to VHF radio sales.
Wearing heads: A studio buys a new tape
machine. The purchase price is entered in the
books under capital expenditure and the sum
is depreciated over a certain number of years
until, at the end of the last financial year, the
book value of the machine is nil. A new
machine is purchased with the money that has
been allowed for by the process of depreciation
on the old machine and the pattern is repeated.
That is the theory but the practice is complicated by the increase in price of the replacement
machine over the original depreciation period.
Thus, the original machine was bought for £x
and the new one will cost £4x. At the same
time the money itself has depreciated at an
annual rate currently standing at more than 17
per cent. So many financial men are strongly
advocating the general adoption of `inflation
accounting' and have a most persuasive
argument. This is where things are apt to get
a mite complicated and should be discussed
with a good accountant. But a point arose the
other day in discussion with a very good
accountant indeed, which ringed round the
importance of a client giving his professional
advisers complete and precise instructions. A
tape machine can be treated as a homogeneous
unit for accounting purposes, depreciated as a
unit and finally written off as a unit. This
presupposes that all parts of the unit wear out
at the same rate but they don't. Replacement
of the odd component during the lifetime of
the unit is unimportant because it can be
allowed for in the maintenance budget. But
suppose some part of the unit has to be
renewed which will cost as much as 30 per cent,
not of the current book value of the unit but
of the whole replacement cost of the unit, what
then? The part in question was a multi -track
headblock costing a tidy sum particularly to a
studio already hard pressed for cash, and no
separate provision had been made for such
expenditure. The accountant didn't know that
headblocks wear out more quickly than tape
machines and why should he if no one had
thought to tell him. So the problem arose of
having to find some hundreds of pounds in a
hurry and unexpectedly because the performance of the headblock in question had not
even been properly logged. It only goes to
show what can happen in studios where the
management hasn't got it together.
Footnote: If recording engineers do go freelance in any numbers then, presumably, studios
would treat them as casual labour, employ
them on an ad hoc basis and be able to cut
overheads to the bone in consequence.
WE DESIGN
AND
MANUFACTURE
PROFESSIONAL
AUDIO
EQUIPMENT
AT
MODEST COST
rt.i r
!
. t,4' rr"se.w
#
Ay W.
4,r
PHONE OR
WRITE FOR
QUOTATION
NEIL
ROSS AT THE CONTROL OF TWEED AUDIO CONSOLE IN
RADIO
EDINBURGH STUDIO
CHANNEL 4 TRACK STANDARD PORTABLE
MIXING DESK IMMEDIATELY AVAILABLE WITH
COMPREHENSIVE FACILITIES
10
Otari DP4050
TWEED AUDIO
ROSEWOOD INDUSTRIAL ESTATE, KELSO, ROXBURGHSHIRE
STD 057 32
SCOTLAND.
TELEPHONE 2983
this is Otani
CASSETTE COPIER
Ideal for
I
cassette copy or 10,000
From Japan's biggest manufacturer of Tape
Duplication equipment, the DP4050 reel to cassette
copier.
Foolproof operation for non -skilled personnel.
Eight times copy speed.
Automatic cycle through Record -Rewind -Stop.
Absolute consistency in manufacture through
large volume production.
Modular construction.
Servo -controlled direct capstan drive.
NOTE NEW ADDRESSIndustrial Tape Applications
5 Pratt Street, London NW1 OAE.TeI: 01-485 6162 Telex: 21879
47
3 ti D1l I D1t'f.
IN COMMON WITH all recording studios,
wehave our own preconceived ideas about the
relative merits of different microphone types.
Some of these ideas will clearly be based on
experience, but naturally some of them are
open to question as new developments arise.
Consequently this survey of the AKG C414,
Schoeps CMT36 and CMT56, and the
ubiquitous Neumann U87 variable polar
diagram mics was of great interest to us.
To avoid preconceived ideas interfering with
impressions, various tests were carried out
NEUMANN U87i CAPACITOR
MICROPHONE
recording the same material with the three
microphones as close as possible to each other
on to separate tracks of a 38 cm/s Dolby A
tape. Subsequently we listened back to the
tapes on our Spendor BC3 monitor loudspeakers, switching from one microphone to
another-without any of us knowing which
mic was which, and noting various remarks.
Some of the results came as something of a
surprise, since on more than one occasion we
all preferred microphones which previous
opinions might have ruled out of court.
The choice of which microphone to use for
which material is, we feel, too often left to
preconceived ideas and we hope our comments
in this comparison will at least provide scope
for experimentation by adventurous engineers.
All of the microphones offer more or less the
same facilities, and are in the same price
bracket as each other-indeed all are very fine
microphones well worthy of their reputations.
is a Cannon connector with an extended shank.
circuit board inside the mic case is set to
`external'. The connector is three -pin Cannon
and either a standard U87 head -cable can be
used or else a suspension mount (Z48) can be
The microphone can also be externally
powered by the customary 48V xy phantom
system, when a readily accessible switch on the
By Angus McKenzie
and Tony Faulkner
AM/TF
MANUFACTURERS' SPECIFICATION
Acoustic operation: pressure gradient transducer
Output into 1 k52: omni, 0.8 mV/µbar; cardioid,
0.9 mV/µbar; figure -of -eight,
Recommended load:
1
k52
1
mV/µbar.
or greater (250
d2
or
greater).
Nominal impedance: 2000 (500).
Capsule capacitance: 2 x approx 53 pF.
Self -noise: approx 26 dB to DIN 45 405.
Sound pressure to 0.5% harmonic distortion at
40 Hz, 1 kHz and 5 kHz: without pad greater than
200 µbar=120 dB; with pad greater than 650 µbar=
130 dB.
Phantom power requirement: 44V to 54V.
Current: 400 µA.
Price: £150
Manufacturers: Georg Neumann & Co, 71
Heilbron/Neckar Fleinerstr 29, Postfach 2120,
Germany.
UK distributors: FWO Bauch,
Street, Boreham Wood, Herts.
49
Theobald
270"
The Neumann U87 is very well established in
many of the London studios, as well as around
the world. It was described as 'the most
reliable mic we have come across' by one
studio we telephoned to compare notes before
completing this survey.
The microphone is the largest of those under
test (200 mm long and 56 mm in diameter) and
also the heaviest (over 400g). Although this
makes life difficult for light-fingered visitors
to the studio, it also provides a potential source
of inconvenience with boom -stands on full reach (particularly the smaller variety).
The U87i is the fet version of the U67 (which
is still widely used) and has switching for
figure -of-eight, cardioid and omni-directional
polar patterns no hypercardioid (cottage loaf). The mic can be internally powered with
two batteries, which could be of great convenience, and a battery state meter is incorporated
in the body. The batteries are automatically
switched on as soon as the U87 stand -adaptor/
head cable is connected, by means of a microswitch depressed by the connecting plug which
48
STUDIO SOUND, JANUARY 1975
4
31
-
to
125 Hz
1 kHz
4 kHz
8
kHz
kHz
12.5
Curves
identical
t
shown,
too [he
1
kHz e curve
bought and simply use any normal XLR to
XLR microphone connecting cable. A windshield is available at a modest price (WS67)
which is a sponge sleeve and seemed to function
quite adequately with fairly close speech,
although it may not be completely satisfactory
for the uncommon application of outdoor
recording.
Apparently the U87 circuit has recently been
modified to improve overload margins-but
inspection of the current circuit indicated no
current feedback around the single fet since
the source was decoupled by means of a 20 [i.F
capacitor to earth, which might contribute to
intermodulation distortion.
The circuit design incorporates a -10 dB
switch for sensitivity, which is effected by
means of a 560 pF capacitor connected in
parallel with the microphone capsule itself;
this reduces the input to the gate of the fet.
There is also a bass roll-off switch on the body
of the microphone which cuts the response at
100 Hz by four to five dB and at 50 Hz by
around eight dB according to the published
specification. As mentioned earlier, the basic
circuit consists of a single fet, with the feed to
the primary of the output transformer coming
from the drain via an electrolytic decoupling
capacitor. A further fet is incorporated in the
circuit as a voltage regulator.
The microphone is very sturdily built, and
seems very unlikely to fail mechanically unless
mistreated unforgivably or else most unlucky.
As far as actual sound quality is concerned,
we found it most acceptable for most applications, with a few exceptions. The noise level
was, subjectively, very low indeed, and would
be unlikely to cause any problems. The polar
diagrams, particularly at high and low frequencies, were not altogether exemplary, but
at least the high frequency end can partly be
put down to the large capsule diaphragm
(2.5 cm) which is equally responsible for its
characteristic sound quality. The front -to -back
ratio in the cardioid position was rather poor
at low frequencies, and we feel that this would
benefit from some attention by the manufacturers since it could prove a problem in some
circumstances, particularly in small studios
already suffering from isolation problems. It
could also prove annoying in a situation where
one is using a number of spaced microphones
in a classical music balance-any rumble
present in the recording location would be
rather exaggerated by the almost omnidirectional polar response at low bass frequencies.
In the figure -of-eight polar diagram, the
U87 has significant bass roll -off (4 dB at 50 Hz),
but in this pattern it is very good in terms of
'p' popping on voice. Ninety degrees off axis,
AKG C414 CAPACITOR
MICROPHONE
By Angus McKenzie and
Tony Faulkner
MANUFACTURERS' SPECIFICATION
Type: pressure gradient receiver (twin diaphragm
condenser microphone capsule with fet preamplifier).
Frequency range: 20 to 20 kHz.
Directional characteristic: switchable pattern
selection of cardioid, omni-directional, figure -of eight and hypercardioid.
Sensitivity at 1 kHz: 0.6 mV/µbar.
Capsule capacity: 2 x 100 pF.
Impedance (20 to 20k): less than 200 ohms.
Load impedance: greater than 500 ohms.
Operating voltage: 9V.
Universal phantom powering: 9-25V (within the
range 7.5V to 9V dc with proportionately decreased
sensitivity).
Current consumption: less than
5.5 mA (DIN
45 596).
Unweighted noise level: 3 µV eff.
Equivalent noise level: 21 dB spl
CCITT -C DIN
(0.6 mV/µbar
45 405).
Price: £160
Manufacturers: Akustiches U. Kino Gerate G
mbH, A-1150 Vienna 15, Brunhildengasse 1,
Austria.
UK distributors: AKG Equipment Ltd, Eardley
House, 182-184 Campden Hill Road, London
W8 7AS.
The AKG C414 microphone is the fet transistor
version of the C12A nuvistor microphone
which is well known, particularly in broadcast-
the U87 is down in top in both cardioid and
omni functions, and this could prove disappointing if one is relying upon a coincident pair
for the main balance of, say, an orchestrawhere the centre of the stereo image would
lack treble definition.
As far as applications are concerned, the
U87 seems well suited to most applications,
particularly percussion and brass. We were
not all that happy with the tone on strings,
where the quality seemed somewhat hard and
brittle. In general we preferred other microphones for strings, such as the Neumann
KM84 or AKG C414, but this is very much a
matter of taste-with particular reference to
one's choice of monitor loudspeaker. There
seemed to be something of a `nasal' presence
boost, which might sometimes be desirable,
particularly with some makes of monitor
speaker-but we did not altogether like it.
The quality on brass was most vivid, and
very clear without being clinical. There was
again something of a nasal coloration, but in
this case it flattered the sound to advantage.
We would put this down to a combination of
the resonant frequency of the large capsule,
and to the shape of the mic case. Our reservations regarding the string quality can be
extended to the use of the Neumann U87 for
harpsichord and piano recordings, where we
would again prefer one or two other microphone types, unless one likes a nasal quality
for some specific reason of production. The
coloration seemed by no means easy to
ing circles. We have two C12's, two C4/2's
and two C414's in our own mobile recording
unit, and we have always been most satisfied
by their performance. The C414 has not the
same following as the Neumann U87 in London
studios, and we feel that this is not obviously
explicable-since it has several extra points in
its favour, as well as a good overall performance.
The microphone itself is considerably smaller
than the U87 (about 11 mm long) and is also
considerably lighter (200g). The casing does
not appear as robust as that of the Neumann.
In common with the U87, the C414 requires a
special head -cable with its own stand-adaptor
-which in the case of the AKG employs a
Cannon six -way connector (like the C12A) that,
regrettably, in our experience is occasionally
unreliable, particularly with metal fracturing.
We understand from AKG in London that
there is a modification available to make the
C414 into a standard three-way XLR connection which will be of great advantage. Nonetheless, even with the six-way Cannon mic
connector, the cable can be supplied terminated
in a standard XLR connector.
The C414 has switching for four polar
diagrams-cardioid, omnidirectional, figure-ofeight and hypercardioid (cottage -loaf, ie halfway between cardioid and figure-of -eight). The
inclusion of hypercardioid is most useful,
offering more flexibility in applications (such
as particularly encountered in broadcasting)
where one employs just a very few microphones
for an overall balance of, say, an orchestra and
equalize out; it was much easier to make
another mic sound like the U87 than it was to
make the Neumann sound flat.
On voice, the U87 showed very high clarity
-sibilants were exaggerated a little, but the
overall quality was very good. Although the
sound from the mic did not sound as faithful
to speech as some other mics, the effect of
enhanced clarity and presence could be of
some advantage. Extending the idea of using
the U87 for voice, we used the mic for a recording session in a church in Surrey where we
were recording a small madrigal group. The
U87 again showed very good clarity, but this
time the coloration, which aided intelligibility
in speech, did not enhance the vocal quality of
the choir and gave it rather a hard tone.
All in all, we are impressed by the microphone, whose performance in our studio makes
it clear why it is so widely employed in recording studios. However its characteristic sound
does not flatter everything it meets. On speech,
percussion and brass it can be recommended
to most potential users-but for strings, choirs,
piano etc, we found it rather `hard' and as
such not universally applicable. The microphone was most reliable and robust all the
time we had it in our recording set-up, and
remarks from other London studios would do
much to confirm the U87's reputation as a
consistent, sturdy microphone which always
works. Obviously there are sometimes minor
problems as with other mics, but the usual
problems of rf breakthrough and noise chattering seemed totally lacking.
the overall pickup of hall ambience has to be
controlled in the main balance. The mic is xy
phantom -powered from any voltage between
7.5V and 52V, with the provision of suitable
feed resistors in the power supply for different
voltages as recommended by AKG; used on
48V the C414 draws a fairly high current.
This range means that the microphone is
compatible with most xy phantom systems
normally encountered, and can be used with
the 9V battery units also supplied by AKG for
use with the C451 series. One problem with
the use of the battery power supply has been
the increase in microphone self-noise as the
voltage from the battery nears the 'knee' of
the zener diode incorporated in the power
circuit of the C414. With a new battery, the
microphone is quiet; as the battery volts drop,
the noise increases a little, and then it returns
to its low level after the battery voltage has
dropped further. A sturdy windshield (Wll)
is available from AKG and seems to perform
quite satisfactorily.
AKG in London say that there are plans to
introduce a modified circuit to improve overload margins further-with more feedback, and
incorporating a bass-roll-off provision in due
course. Early models of the C414 did have
problems with rf breakthrough in unfavourable
situations, but we understand this has received
prompt attention and that the performance is
now markedly better and will be improved
further on the introduction of the new XLR
50
49
AKG C414
Polar Diagram:
160°
ISO.
type stand adaptor; this will incorporate rf
suppression.
The microphone circuit incorporates a
2 MHz oscillator for obtaining the 60V dc
polarizing voltage for the capsule from the
incoming phantom volts. The 2 MHz oscillation is half-wave rectified and stabilized for the
low current required. The microphone head
amplifier circuit is basically an fet source
follower driving an emitter -follower, which in
turn drives the output transformer via an
electrolytic decoupling capacitor. In the case
of the C414 the source of the fet is not bypassed
by a capacitor (contrary to the U87) and we
feel this could help reduce intermodulation
120'
120°
CC
0
60°
60°
OW Hz
00°
distortion.
The self -noise of the C414 did not seem quite
as low as that of the U87, but we can see few
occasions where it might cause difficulty since
it was still in the 20 phons region and was
very good (in fact the quietest in the AKG
range).
The overall frequency response was, subjectively, very wide, with an extended bass
response which could be either an advantage
or a disadvantage depending on application.
A suspension mount would get rid of most
potential problems, as would a high-pass filter
setting such as may be found on professional
microphone amplifiers. This extended bass
was most suitable for organ recordings and
also for large orchestras-although it would
bring out rumble in some locations, which
could easily be cut out with a suitable filter as
previously mentioned. This low end presented
rather a problem for speech application, where
it gave the voice a strange detached sound-the
low end did not seem to `belong' to the top
end. Nonetheless, the quality was good and a
little equalization helped.
The polar diagrams seemed excellent, as
discovered last year when we carried out some
experimental recordings in an anechoic
chamber. Although the C414 has a large
capsule (2.5 cm) in common with the U87, it
does not appear to exhibit such a significant
loss of treble off-axis, and a coincident pair
gives a very convincing stereo image. The
microphone incorporates a useful -10 dB
sensitivity switch.
As far as the accuracy of reproduction, and
`sweetness' of sound is concerned, the AKG
C414 was very good. The string tone was very
pleasing and flattering, as was the quality on
piano and harpsichord. String tone seems the
forte of the C414, and we would have no
shame in recommending it, if only for this
application.
The rumble pick-up was clearly evident when
we came to play back our madrigal singers test
recording made in a Surrey church, which
suffers a little from distant If rumble from
Heathrow Airport. However, the vocal quality
had a pleasing warmth which was lacking on
the U87.
On orchestral recordings, the C414 microphones always seem to give a clean top, which
is subjectively very pleasant-and the string
tone makes it a most apt choice for this application. The brass quality lacks the vividness and
presence of the U87, but was by no means
failing, and for any recording engineer who
wants to try a different `sound' the AKG
C414's are well worthy of investigation. The
treble response greatly enhanced the quality of
guitars and harpsichords, although it gave
speech quality rather exaggerated sibilance.
Concluding
Generally speaking, we are very happy with
the AKG C414, and we have, as stated earlier,
several in our recording set-up which are used
a great deal. We have used four in a coincident
cardioid `cluster' for quadraphony with great
success-our only reservations are mainly
concerned with mechanical robustness, particularly of the six -pin Cannon stand-adaptor/
connector, and with the speech quality which
was a little boomy and `tizzy' before equalizing.
52
Broadcast pattern audio jackfields
from Festure Film Developments
19"
Rack
Mounting, from one
to six
rows of
20, 24, or
26 Jacks.
The
Jacks are mounted on a plastic block which
mounted on a
is
Each row is fitted with a
legend (designation) strip and wire support bar. The panel is steel,
cadmium plated, chromate passivated and stove enamelled hammertone silver.
ìn turn
50
STUDIO SOUND, JANUARY
1975
19" panel,
ALSO Audio Patch Cords Microphone Cable
Installation Cable Multiway Cable Post Office &
Rendar Jacks Cable Markers Lever Keys Linear
Faders Cannon Connectors Preh Connectors
Tuchel Connectors Switchcraft Connectors Military
Trí-Lock Bayonet Connectors Audio Attenuators
Wahl and Weller Soldering Irons PML Microphone
Accessories Hellermann Sleeves and Tools Crimp
Terminals Cable Drums A.B. Engineering Wire
Strippers and De -Solder Guns.
FUTURE FILM DEVELOPMENTS,
90
Wardour
Street,
London W1V 3LE.
Tel: 01-437 1892 Telex:
21624
Take a Quad 50E Amplifier
(a good start for any installation)
plug it into your monitor system and it
bridges 60052 lines to drive your speakers.
Take that same amplifier and, without
changing it in any way, plug it into another
installation to deliver 50 watts into 100 volt
line * from a 0.5 volt unbalanced source. This
versatility and its attendant easing of stocking
and maintenance problems is one reason why
large organisations use the Quad 50E.
* or indeed any other impedance from 5 to 250
ohms.
Other advantages appropriate to users of al I
sizes include Excellent power and frequency
response (-1dB).
Low distortion (0.1% at 1kHz at all power
levels).
Low background (better than 83 dB referred
to full output).
Pre-set level control adjustable from front
panel.
Unconditionally stable with any load.
Proof against misuse including open or short
:
circuited output.
Small size (4
324mm).
"
x 64" x 124 ") - (120mm x 159mm x
QUAD
Products of
The Acoustical Manufacturing Co. Ltd.
for the closest approach to the original sound
QUAD is a Registered Trade Mark
Send for details to Dept SS, Acoustical Manufacturing Co Ltd,
Huntingdon PE18 7DB Tel (0480) 52561
:
SCHOEPS CMT 36 AND CMT 56
CAPACITOR MICROPHONES
Angus McKenzie and
Tony Faulkner
By
MANUFACTURERS' SPECIFICATION
Frequency range: 40 to 16 kHz.
Directional characteristics: (mechanical adjustment): cardioid, figure -of -eight, omni.
Output level (1 kHz in cardioid): -38 dBV/10
dynes/cm'.
Sensitivity (1 kHz in cardioid): 1.2. mV/dyne/cm'.
Spl at 0.5% the (into 1 kO audio range) cardioid:
for CMT36; 126 dB spl for CMT56.
Equivalent noise loudness level (CCITT): 26 dB
128 dB spl
spl approx CMT36; 23 dB spl approx CMT56.
: -106 dBV approx CMT36;
-110 dBV approx CMT56.
Source impedance: approx 20 ohms symmetrical
CMT36; approx 200 ohms symmetrical CMT56.
Load impedance: greater than 600 ohms.
Phantom power: 12 (9)V CMT36; 44-52V CMT56.
Current: approx 8.5 mA CMT36; approx 650 µA
CMT56.
Noise voltage (CCITT)
Price: £195, £187.
Manufacturers: Schalltechnik Dr-Ing. Karl
Schoeps, 75 Karlsruhe 41, Spitalstrabe 20, Postf
Germany.
UK distributors: Feldon Audio,
land Street, London WIN 5PH.
410970,
126
Great Port-
The Schoeps range of capacitor microphones
has not apparently received the interest and
acclaim in the UK it has had elsewhere in the
world (partly in the USA and parts of Europe)
and our tests would indicate a certain injustice.
Both microphones are similar in appearance
and facilities offered, with some internal
electronic differences. The Schoeps is a pencil
microphone similar in size to a Calrec CM 1050
or AKG C452, only it is a side-shot mit+(ie it
picks up from the sides, rather than from the
top).
It employs standard XLR three-pin-connection, and offers cardioid, omni-directional and
figure -of-eight polar patterns. These are not
obtained by means of changing the polarization
of a double -diaphragm (the technique employed
by the Neumann U87 and AKG C414); they
are achieved mechanically by the twist of the
mic cap, which has click -positions for each
pattern.
The first difference between the CM736 and
CMT56 is the powering. Both employ xy
phantom powering, the CMT36 operating
nominally on 9-12V (although we are advised
it will function on 48V with suitable feed
resistors), and the CMT56 operating on 48V.
The basic difference between the two models
is that of amplifier design. The CMT36 has
no output transformer at all (offering, we
imagine, some reduced distortion and improved
transient performance) and the CMT56 has a
single fet with the drain feeding the primary of
an output transformer via an electrolytic
decoupling capacitor. In place of a transformer
in the CMT36, the fet drives two p -n-p transistors. The drain of the fet feeds one base via a
capacitor, and the source of the fet feeds the
other base. One leg of the audio output comes
from one emitter direct, and the other leg from
the other emitter. The dc volts are extracted
from the midpoint of the two collectors (which
are joined one to the other) and two resistors
connecting base to base. The source load of
the fet is not capacitatively decoupled (different
from the Neumann U87) and this current
52
STUDIO SOUND, JANUARY 1975
feedback should reduce intermodulation distortion in the amplifier. The sound quality of the
CMT36 and CMT56 did not appear to differ
particularly in any of our tests; indeed we were
most enthusiastic about both in all of them.
The general impression gained from all the
comparisons was one of extreme flatness
without any particular coloration. The polar
diagrams were audibly good, particularly that
of the figure -of-eight; on one recording session
we used just a pair of these microphones in
coincident figure -of-eight configuration (90° à
la Blumlein) and the reproduction was most
impressive Listening on headphones provoked
turning around on several occasions, convinced
that someone was talking-but it was the
microphones!
When we replayed the recording made of the
madrigals, the sound was very smooth and all
of the words were very clear, without excessive
rumble from London Airport, and with a very
good extreme top. A distinct lack of intermodulation distortion was evident, and was
most refreshing.
The stereo definition with a single pair of
these microphones put many a multi -microphone balance to shame, and the placement
was most convincing in terms of front and
back of sound-stage. It seems to us that the
Schoeps is very widely applicable since it does
not seem to have any particular sound of its
own other than a great sense of clarity. This
feature means that the sound it gives can be
`curve-bent' to requirement. The string tone
was very clear and true although it lacked the
`flattering' C414 sound, and the brass was also
very clear, although it lacked the vividness of
the U87-but we feel that mic channel equalization could change this situation.
As must now be clear, we are very enthusiastic about the Schoeps microphones-their
flatness gives a great deal of scope to the
creative engineer. As they have not established
themselves firmly in the UK it is not easy to
make comments regarding long-term reliability
-but our brief experience does not indicate
any likely problems.
One UK user, Bob
Woolford, told us of only one difficulty he had
with them-a while ago he was recording
out-of-doors on an island off Spain with them,
and a late night session broke off at 4 am for a
break. When he returned, the microphones
were behaving far from healthily-this turned
out to be rather large volumes of dew! When
the dew was wiped off carefully, all was well
--
1000
5000
---10000
Hz
again.
The choice of which microphone to use is a
most interesting one, and this survey has made
us very keen to try different microphones in
72
ninwse
ALL RIGHT
FOR 7 or 8
plus a couple
of
echo returns...
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it memorises everything
and gives it back to you
faithfully... every time.
Quad /elgh[ by
(FELDDN
helps you through the night
et
zt
.
i
On Easter Sunday 1964 the
medium airwaves suddenly
and illegitimately carried the
voice of Simon Dee
saying 'Good morning ladies and
gentlemen' this is radio
Caroline broadcasting on 199,
your all-day music
station'. Ten Years later, almost
to the day, Piccadilly
Radio started legitimately
broadcasting in
Manchester. It was an eventful
decade for British radio.
The
continuing
story
of ILRRadio
Manchester
ADRIAN HOPE
54
STUDIO SOUND, JANUARY 1975
RADIO CAROLINE WAS the first of the
score of pirate stations that were doomed to
eventual extinction under the axe of the 1967
Marine Offences Laws. Piccadilly Radio was
the fifth of the projected three -score legal
independent local radio stations made possible
by the Sound Broadcasting Act of 1972 and
the Independent Broadcasting Act of 1973.
Without the good ship Caroline and all who
sailed on her, there would have been no Radio
Piccadilly, no Capital, no LBC, no Radio
Clyde, no Birmingham-no nothing but the
BBC. So it is fitting that a fair number of the
engineers, disc jockeys and entrepreneurs who
received a leaden handshake under the 1967
Act are now employed by or running Britain's
legal commercial radio stations.
They are giving the BBC national and local
stations a hard run for their money; although
Broadcasting House gleefully published
audience rating figures that seemed favourable
to them, it had to ask Capital's Kenny Everett
to call off his listeners after Kenny invited
them to phone into the BBC with their comments on these ratings. To put it another way,
it is just not possible that a station like Capital
-with the Everett and Cash morning shows,
plenty of good music and a bottomless pit of
new ideas for programmes and promotionswill not make considerable inroads into BBC
Radios One and Two and Radio London
listening figures. If and when the great British
Public becomes used to the idea of an all news
station, it is not probable that they will wait
patiently for a BBC bulletin when LBC is
offering continuous news. Radio Clyde has
not only brought stereo radio to Glasgow for
the first time ever (neither BBC national nor
local radios had a pilot tone to offer up there)
but it has brought truly local news reports. As
James Gordon, managing director of Radio
Clyde, told the IPA Society recently, Glaswegians are not particularly concerned about
hearing what traffic conditions are like in
London. Don't laugh, he said, as we laughed.
That is what BBC radio has been offering us.
After the awful hiccough when I tried to
write up Capital Radio soon after it went on
the air (and failed through what turned out to
be some missing links in the PR chain) I have
been back to Euston Tower several times and
been made to feel very welcome each time.
Most of the teething troubles, both off and on
air, seem to have disappeared and I would
think that the one lesson to be learned from
the launch of LBC and Capital is that starting
a radio station from scratch in four months
may be physically possible (both LBC and
Capital made their deadlines) but it is as
pointless an exercise as climbing Everest with
one leg strapped behind your back.
On arrival at the railway station, the first
thing I saw were vast posters on the platforms
advertising Piccadilly on 261. I was directed
without problems to the radio station building,
which is in the Piazza of the à la mode Piccadilly
Plaza shopping and hotel complex in the
centre of Manchester. The lack of problems
wasn't surprising because the Piccadilly Radio
offices are not exactly hidden. Along the edge
of the Piazza stretches what must surely be the
largest advertising poster in the UK, if not the
world. 24m high and 600m long, it runs round
the entire south-west corner of the building.
It may not be modest but I'll bet it gets people
tuning in.
Upstairs in the studios I met Geoffrey White,
the chief engineer, along with his assistant
Philip Thompson and two engineers from the
IBA northern area who just happened to be
there on a routine visit. This was particularly
fortunate because it enabled me to talk (and
thus now write) not only about the Piccadilly
station itself, but also about more general
matters of reception on medium wave and vhf
in the north of England.
As emerged from the Capital article and
subsequent correspondence and research, there
is no consistent policy of co -sitting BBC and
ILR transmitters. This should present no real
problem on the medium -wave bands, but on
the vhf bands (and especially in stereo, where
a good signal strength is necessary for hiss -free
reception) problems can and will arise if a
listener has a directional aerial sited on a BBC
transmitter and thus off-beam and excluding
the ILR transmitter. A tangled web of good
and not -so -good reasons explain why co -siting
is not possible and, in a nutshell, the problem
can be summed up as follows:
Because local radio is local rather than national (as are BBC One, Two, Three and Four)
separate services must be transmitted to cover
separate small city areas all over the country.
Because there are just not enough medium
wave and vhf wavelengths to go round, some
different stations must share the same wavelengths. In order that the transmissions from
one local station shall not break through into
the transmissions from another station using
the same wavelength, the aerial systems used
must be directional (ie transmit the power just
where it is needed and nowhere else) and of
sufficiently low power to fall short of the area
covered by a station with a shared wavelength.
For instance Glasgow Radio Clyde has been
allocated the same vhf frequency as Swansea
(95.1 MHz). The Manchester vhf frequency
97.0 MHz is shared by Tyneside-Wearside,
with both these stations sharing 261 on the
medium wave with LBC (permanent frequency),
Glasgow, Birmingham and Plymouth. The
extent to which stations share the same wavelength gives some idea of the fine balance
which must be drawn between sufficient
strength to cover the intended area satisfactorily and insufficient strength to crash in on
another station. Whereas the BBC uses both
horizontal and vertical polarisation techniques
to enhance separation between sharing vhf
stations, the IBA has adopted circular polarisation for vhf on all independent stations (this
gives improved results for portables and car
sets operating with simple whip aerials). Thus
there can be no isolation of ILR stations by
polarisation characteristics.
So far the
directionality of the IBA aerials, the transmission powers used and the physical spacing of
the transmitters on shared wavelengths has
produced no real co -channel interference
problems. But of course, the number of ILR
stations in operation is still in single figures
and it is anyone's guess how successfully the
system will work in practice, if and when the
eventual target of 60 separate stations is
reached.
The best thing we can all do is keep our
fingers crossed and hope that the IBA theory
works out in practice.
Whereas commercial television and BBC
Left: How they started out.
Above: How they've ended up.
television now transmit on vhf from shared
aerials, there is no such rationalised scheme of
sharing between BBC national and local radio
and the ILR transmitters. The result, as we
have seen, can be exclusion of the ILR signal
by a directional aerial lined up on the BBC
mast. When the BBC started to realise its
plans for 40 local BBC radio stations, the laws
to set up commercial radio had not been
passed and thus there were no firm plans for
any ILR stations. Of course any farsighted
planner or politician worth his salt would have
known that commercial radio would eventually
come to this country, but in the absence of any
such foresight, the BBC was left to its own
devices and naturally started to transmit local
radio from the national or regional BBC vhf
transmitters (Wrotham in Kent for London,
and Holme Moss for Manchester). Because
the regional transmitters were intended to
saturate large areas of the country rather than
just city centres, they were usually miles away
from the service area and thus the local radio
stations needed to put out a fair amount of
power to reach their intended city audiences
(Radio London uses 16.5 kW erp for mono vhf
transmissions from Wrotham). Listeners sited
their receiver aerials on the BBC transmitters
and as often as not used directional multielement arrays to exclude interference and
unwanted reflections. When the IBA engineers
started to look round for suitable sites for their
transmitters (which, remember must transmit
with low power to cover just a selected city
area with no interference to other city stations
on shared wavelengths) there were very few
locations where aerial -sharing between the
IBA and BBC would have worked for local
transmissions. As a result we have the IBA
transmitters popping up all over the country,
usually miles from the nearest BBC transmitter,
thus by virtue of parallax inevitably out of line
with many receiver roof aerials carefully aimed
at the Beeb's stalks. In such cases 'a wet piece
of string' would serve better as an aerial to
receive IBA radio than an extensive multielement directional array.
So far, many people listen to local radio on
portable sets fitted with a simple whip aerial
so that the different location of the transmitters
is of little consequence.
The problems in
practice will only make themselves fully felt
when more listeners start to listen to local
radio in vhf stereo via directional roof aerials
sited on the BBC transmitter. Then the
relatively low signal strength will manifest
itself as a thoroughly unpleasant hiss. It may
well be years before sufficient people start
listening in stereo to realise that they can't do
so without rethinking and reorganising their
aerial system. When that time comes listeners
may be excused some resentment over the
inability of the BBC, the ITA (as it was then)
and the Ministry of Posts and Telecommunications of several years ago who could not then
muster sufficient foresight, forethought and
cooperation to plan for a future of local BBC
and commercial radio. They may also wonder
why the Government and local planning
authorities have made it possible for developers
to build skyscraper blocks in our cities (thereby
making transmission and reception in those
cities even more difficult) but still have the
right to refuse space on their roofs for aerials
to transmit local city radio and similar services.
I raised some of these points at Manchester
and gather that, as yet, there have been no
problems encountered with regard to reception.
The fm transmissions radiate from Saddleworth
with 2 kW erp (the medium wave transmissions
are from Ashton Moss, ten or 12 miles out of
the city centre, also at 2 kW erp). Tests made
by Geoffrey White suggest that the planned
and intended 60 dB (1 mV per meter) contours
are being met. Both the fm and medium wave
transmitter aerial systems are highly directional,
the latter having four out of line masts to
produce the necessary nulls.
The medium wave signals are piped to
Ashton Moss via Post Office land lines but, in
the special case of Manchester, the signals to
the fm transmitter at Saddleworth are carried
by a pair of uhf links operating from aerials
on the Piccadilly Radio building roof. The
signals are sent up as a stereo pair (on 934 and
938 MHz) with encoding at the transmitter.
This facilitates circuit tests-one leg can be
fed and the other checked, even during
transmission.
The Marconi transmitters,
which operate unattended, remain permanently
on except when servicing is necessary. The
transmitters have some power in reserve but
it is unlikely that this can ever be used because
the Manchester signals would then interfere
with Manx radio on the Isle of Man.
There seems to be some tacit back-scratching
between the IBA and the Manx station, which
has so far avoided what could be an awkward
source of mutual interference.
Piccadilly Radio went on the air on the
predicted date (April 2) after a year's planning.
Geoffrey White and Philip Birch first started
working out the station details in April 1973,
having been given a clean slate to build it from
scratch. The premises which they were able
to obtain are almost too good to be true.
Around 10 000 square feet of empty space
was available in the Piccadilly Plaza; while at
his previous job as technical consultant with
the Granada Group, he worked full-time to
shape the station. Geoffrey White seems almost
obsessively tidy, with an abhorrence for trailing
cables and untidy wiring. The result is that the
station (although not yet quite finished) is
remarkably free of clutter. It is clear that this
is no happy accident. For instance, before the
channels for the cables were let into the floors,
full-scale plywood mock-ups of the control
desks were built and positioned exactly in their
intended positions to place the channels just
where they are needed. The use of mock-ups
also enabled the designers to be sure that
operators would be able to reach what they
wanted to reach when they finally sat down and
went on the air. As opening day approached,
the three-day week hit the station, but all
concerned are very proud that they finally met
the deadline.
Piccadilly is staffed by about 75 people, of
which eight are engineers, some from the BBC
and some ex-IBA.
In keeping with the
philosophy behind local radio, many of the
station shares are owned by local newspapers,
including the Bolton Evening News and the
Rochdale Observer. Other shares are owned
by Granada. The idea behind offering local
56
55
SECOND
STUDIO ENGINEERS
REFRESHER COURSE
THE FIRST COURSE
WAS OVERSUBSCRIBED
THE NEXT COURSE WILL BE
SEPTEMBER 1975
For information, write now
APRS SECRETARYE L MASEK
23 Chestnut Avenue,
Chorleywood, Herts
WD3 4HA
RADIO MANCHESTER
radio shares to local newspapers is, of course,
to compensate those newspapers for the likely
loss in advertising revenue. The Piccadilly
Radio rates seem reasonable. A 30s spot, for
instance, costs £4 between 1 am and 6 am, £10
between 7 pm and 1 am, £22 between 2 pm and
7 pm and £34 between 6 am and 2 pm. The
station put together its own ID jingle package
under the production of Bob Snyder with the
music of John Cameron (of CCS fame). Some
of the adverts on the air are produced outside,
but a fair number are produced by Piccadilly
Radio.
Costs vary between a minimum of £10 for a
simple announcement on cartridge to £200 or
more for a special production with original
music. Piccadilly currently has plans to build
a special jingle studio to handle the fair
amount of work which is coming in from local
advertisers; some of the home-grown adverts
that I heard, both at the studio and on my
portable radio in Manchester over the following
weekend, are very reasonable indeed. There
seems to be more effort to inject humour into
adverts in Manchester than in London, which
if it works can be highly successful and if it
does not work can be excrutiatingly embarrassing. I didn't hear anything in the latter
category possibly due to the station policy of
refusing to broadcast anything really bad; on
the whole listening to the station is a fairly
pleasant experience. True a few of the news
broadcasts jarred a bit, and this is one area
where any amateurism shows. Over the years
we have grown used to hearing the BBC news
readers pronounce everything correctly and
56
STUDIO SOUND, JANUARY 1975
never fluff a line.
When the commercial
stations have matched the BBC (the Broken
Biscuit Company as they like to call it), then
commercial radio will have really arrived.
Capital and LBC, incidentally, have greatly
improved their newsreading recently.
Piccadilly Radio is adamant that it wants a
station image, not an image of individuals.
Thus although their two top disc jockeys,
Roger (Twiggy) Day and Steve Merike, are
both pretty flamboyant personalities, the name
of the game is to make Piccadilly instantly
recognisable as Piccadilly within a few minutes
of tuning in. They have nine hours a day of
needle time, but usually do not use it all,
probably largely due to the three-hour shutdown. But the station may eventually go 24hour. There seems to be rather less phone-in
than on the London stations; Piccadilly policy
here is to use an expert in a studio and
encourage listeners to phone in with questions
rather than opinions. If the anchor -man in the
studio senses that the caller has something
worth saying, he then draws the caller out.
This way, in theory at least, listeners are
spared opinionated lectures from boring callers.
There are ten phone lines into the studios
(with the possibility of hitching-up another
seven if necessary), these being fed straight
through to the consoles, each caller being given
and told his line number. The broadcaster has
a series of numbered buttons corresponding to
numbered lights which show up where calls
are available. By pressing button No. 1, he
can punch straight through to the caller on
line No. 1 etc. There is also facility for conference calls if necessary. So far Piccadilly is not
routinely using the 7s tape delay which the
IBA insists they must have to hand for use
when necessary. General policy seems to be
to attempt the programme live, for with delay
there is always the risk of confusion due to the
delay of the received programme on the caller's
radio. But the broadcaster can always switch
to delay when trouble is brewing. The switchover is usually handled by the use of 7s jingles
to inject the necessary blocks of time. Perhaps
just as effective as the tape delay system (which
I am assured was the invention of a certain Mr
Goebbels in Germany way back in the
Thirties) is the rather simpler `black list'. The
switchboard operators soon learn to recognise
the names, and even the voices, of callers who
have already proved themselves better left
hanging on an empty line than allowed on to
the air to bore or abuse listeners. I am reliably
assured that one whole vast family is already
on the radio station black list, but no one will
tell me what it was that they did in the first
place to get there.
Most of Piccadilly's output is in stereo with
only the telephone calls, sports broadcasts and
emergencies switched over to mono. In an
effort to check quality, Geoffrey White and his
team sat in shifts for 24 hours and recorded
everything the station put out in stereo,
monitoring the levels on the ppm meters of a
Neve desk. One thing they found out bothered
them, and I've been asking around and find
that they are not the only ones who have
noticed the phasing problem with cartridge
machines. The problem is that the cartridges
themselves are essentially fairly cheap plastic
items which carry a stereo recording and cue
tones on a continuous loop of tape. All is well
with the cartridge system until the two stereo
channels are summed to provide a mono signal
(either at the transmitter or in a receiver).
When summing takes place any differences in
phase between the two stereo channels will
cause unpleasant audible phasing effects and
this means that the azimuth alignment of the
heads on all the machines used for recording
and playback must be accurately compatible.
Unfortunately it is emerging that in practice
this is very hard to achieve. The problem is
eased if so-called `Stereo Phase' cartridges
(which are precision made and cost around
twice as much as ordinary cartridges) are used,
but there is still no guarantee that the man who
recorded the cartridge (eg in an ad agency) has
used a machine with correctly aligned heads.
Geoffrey White was even able to show me with
Lissajous figures on an oscilloscope how the
phasing of a cartridge will change as it is
physically touched. Listeners with portable
radio sets are unlikely to be bothered by
phasing effects on the commercials, but as
serious listening to the commercial stations
increases, so will the chances of people wondering why the commercials occasionally sound
odd. And as commercials are what commercial
radio is all about, this is something that can
certainly not be swept under the carpet.
Piccadilly has a total of four stations and
two control rooms arranged in square format
and surrounded by a perimeter of offices and
corridors (in many respects very similar to
Capital in London). The two control rooms
double also as studios for broadcasters who
run and ride their own programmes; the
equipment shows no signs of compromise.
Spendor BC ILIA speakers are used in the
music studio and KEF monitors in all the
control rooms. The speakers are mounted in
a rather clever way. Steel rods run up through
the ceiling to fibreglass hangers on the floor of
the storey above. The speakers are bolted to
these rods and thereby are isolated from the
studio floor and walls leaving the floor free
from cumbersome stands and preventing feed through from room to room. The desks used
are Neve with AKG D202 and C451 and Shure
mikes. Characteristic of Geoffrey White's
meticulous planning is the provision of a
phantom power source for a condenser mike
at all mike positions. The turntables used are
EMT 928s in the studios and Garrard 301s
with Ortofon arms and Shure cartridges in the
listening rooms. The tape machines are Bias
for editing and Leevers-Rich throughout in the
studios. A touch of Neve limiting is used on
fm transmission with off-air monitoring by
McMartin receivers for fm and a Trio on
medium wave. All programmes are logged on
Chilton loggers running at 2.375 cm/s and
churning out two tapes a day. The tapes are
then kept for three months before re -use.
Isolating the studios from outside sound
proved something of a problem for two
reasons. Firstly, the physical construction of
the building was not suitable to allow the
provision of internal brick walls. Secondly, a
busy main road runs alongside the building
outer wall. The fairly complicated answer was
to use a suspended lattice ceiling with lead
sheets hanging as curtains down the inside of
the studio walls, in cavities bounded by plaster.
A series of listening rooms was built along the
length of the cavity wall and these open on to
a corridor. The corridor then opens on to
72
Within 2 years, 4 -channel sound will be the rule.
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astounding quadraphonic effects.
Excellent separation
Both encoding and decoding matrices are
symmetrical. Together with the new QS Vario Matrix in the decoder, an inter-channel separation of 20dB or more is no problem.
well as the quantity of input
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In fact it gives better stereo
perspective than conventional 2 -channel sources.
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Vernitron Ltd., Thorhill Southampton S09 QF England
Sansui Audio Europe S.A., Diacem Building, Vestingstraat 53/55 -2000 Antwerp
Belgium
Sansui Electronics Corporation 55-11 Queens Boulevard,
Woodside, N.Y. 11377, U.S.A.
Sansui Electric CO., Ltd. 14-1,
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39/41 Maple Street, London WIP
7 5FU (Freepost) Telephone: 01-580 5353
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1
SansuL
Sansui equipment is distributed in the
United Kingdom by Vernitron Ltd.,
Thornhill, Southampton.
Dear Sir, Your `Silly Question' (Cleanfeed,
October '74 issue) about 'A' hiring out an
acoustically rotten control room at top rates
to 'B', whose subsequent discomfiture and
fiscal disadvantages appear to be in need of
repair, deserves a less than silly answer-but
not, I counsel, in the form of a High Court
writ.
A large number of studios charge top rates
without having competent acoustic design
applied to the areas involved or to the airconditioning system. My partnership spends a
surprising amount of time trying to retrieve
these situations which should never have arisen
in the first place. Some are irretrievable. Not
infrequently the advice we have given to eager
'A's is not to build the studio complex at all,
or to do it somewhere else. This earns us very
little thanks and no fees from 'A' but does
save prospective 'B's from predictable disasters.
But you asked what action 'B' should take.
He ought to check out 'A's studio facilities
first. Of course he did this in the case you
cited, but chose an expensive and unrewarding
way of doing it, ending up with a useless
master tape. A better method would be to
ask 'A' for a report of the acoustics and sound
insulation of his studio including the relevant
data: reverberation curves, measured background noise levels, and so on. If 'A' can't
provide that 'B' should go elsewhere, thereby
saving time and money. I sympathise with all
the disconsolate 'B's everywhere. Now that
I've written this, however, 'B's should recognise
in future that they could hardly claim `damage
to their reputation as record producers'. If
they can't be bothered to read this and act
upon it what kind of reputation do they have
that could suffer damage? Consider this little
parable: a friend of mine owns a decaying
I NEWS
80 -year -old house in grave danger of collapse.
Within can be found, by looking hard through
the gloom, a few musky threadbare rugs and
an occasional rotting stick of `furniture'. He
proposes to hire it out as a luxury furnished
house at extortionate rates that would enable
one to live at the Hyatt Regency Hotel in San
Francisco instead. I asked him what qualifications this ruin had to earn the title `luxury'.
'The rent,' he said.
Yours faithfully, Sandy Brown, Sandy Brown
Associates, Architects and Acousticians, 12
Conway Street, London W1P 5HP.
Dear Sir, The review published in the November STUDIO SOUND of our Yamaha NS 690
raises some interesting points.
Since the
speaker was submitted for review, the price of
the NS 690s has been reduced to £219.95 a
pair, and I am sure that had the reviewer been
aware of this (we forgot to tell him in time) his
criticisms on a cost -performance basis would
have been less severe.
To some extent this situation is due to
geography and I am certain that if the reviewer
had been based in Tokyo, where Spendor
BC1s, KEF 104s and others cost in excess of
£300 a pair, and Yamaha NS 690s are only
£180 a pair, a different picture would have
emerged. Possibly a review on neutral ground
would be the answer. Possibly Calcutta.
Thank you for letting me air this view in
your column.
Yoursfaithfully, Malcolm Kays, Natural Sound
Systems Ltd, Strathcona Road, North
Wembley, Middlesex.
Dear Sir, In your introduction to the October
issue of STUDIO SOUND under the heading
Greek tv troubles
campaign is
(November) causing problems for
automatically from the encode to Greek television services. Greece
the decode mode by the tape has two television stations one of
recorder r/p switch. Internal re- which is run by the Greek armed
chargeable batteries supply 28V forces. For the first time, television
at 200 mA (mono); their capacity is being used for election campaignis sufficient for 10 hours contin- ing and the Prime Minister, Mr
uous use in the record mode. The Karamanlis, has allowed the parties
stereo unit consumes 100 mA equal time, on the state radio and
more. To save battery power, logic television stations, but the army
ignals derived from the capstan station will not be used for cammotor control circuits set the unit paigning. The right wingers mainin the stand-by mode in the absence tain that it would be intolerable for
of capstan rotation. Physical size communists to sully the screens of
is about the same as the Nagra IV; armed forces television by appearthe whole unit weighs 4.5 kg. ing on them. The opposition have
Future Film Developments Ltd, said that the government has
90 Wardour Street, London W1V bowed to pressure from the military
3LE. Phone: 01-437 1892/3.
establishment and that the armed
58
STUDIO SOUND, JANUARY 1975
THE GREEK ELECTION
`Glossary of Terms' you refer to the need for
definitions of technical terms.
We agree. In fact the APRS issued such a
glossary to its members in 1967 and are in the
process of updating it for inclusion in the new
APRS Handbook, due for publication in 12
to 15 months time.
Those who have points of view they wish to
have considered should write to the Coordinating Editor, John Borwick, B.Sc., Ridge
Cottage, Hill Road, Haslemere, Surrey.
Yours faithfully, E. L. Masek, Secretary of the
APRS, 23 Chestnut Avenue, Chorleywood,
Hertfordshire WD3 4HA.
Dear Sir, We at Neve were very pleased to
read your article in the November STUDIO
SOUND giving details of a visit by John Dwyer
to the Decca Studios in Paris
Société
Française du Son.
So that the record is straight we would like
to correct one or two small inaccuracies in the
article. The channel equalisation units referred
to are not of course 108 but the well-known
Neve 1081, which has been acclaimed throughout the world as one of the most sophisticated
high performance channel amplifiers available.
The reference to transformers below the
photo on page 38 is a little misleading since
some of the information is missing. The hum
actually arose in the foldback circuits external
to the console and not within it as the article
-
suggests.
Finally, good luck to STUDIO SOUND, a very
interesting and well -produced magazine.
Yours faithfully, Peter Moody, Rupert Neve &
Co Ltd, Cambridge House, Mel bourn, Royston,
Hertfordshire.
Sorry, and thank you-Ed
forces station is answerable to comments were echoed verbatim
by
no-one.
a press officer for the massive Rank
Radio International Group, another
retractor; he further stated that the
Audio show
Festival and
Fair, organised by Industrial and
Trade Fairs Ltd, was held from
October 28 to November 3 in the
Grand Hall, Olympia. The show,
sponsored by the Sunday Mirror,
attracted 83 000 fee -paying audiophiles a claimed increase of ten per
cent on the previous year. The
show, the first audio to be organised
by ITF, suffered some loss of
patronage by the big firms of
consumer audio. A spokesman for
Thorn, one of this year's non runners, said that they could `spend
the money better elsewhere'. His
THIS
YEAR'S
AUDIO
group would look to the provincial
fairs for future promotional venues.
Another reason given by manufacturers for their reticence to exhibit,
stemmed from the `fiasco of last
year's show' alluding to the sight
of carpenters and electricians completing stands a day after the show
had been declared officially open.
Genf rally, exhibitors stated that
they were favourably impressed
with the organisation of this year's
fair but wished that the show had
been better supported by other
manufacturers; the gallery above
the main floor remained but half
full.
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59
ti WA Itix
AKG CK9
GUN MICROPHONE
By John Fisher
the complete audio spectrum.
The output impedance of the assembly was
measured at under 300 ohms at frequencies up to
5 kHz, from where it rose to 500 ohms
at 16 kHz.
Whilst this characteristic is quite acceptable for normal purposes, the impedance at high frequencies is
somewhat higher than the specification suggests
and could be troublesome in exceptional
circumstances.
Finally, the current drawn by the system at 9V dc
was measured as 1.7 mA quiescent, which means
that between 200 and 300 hours' life can be expected
from a PP3 size battery driving the system, as is the
case with the optional type B46E power unit.
Hugh Ford
MANUFACTURER'S SPECIFICATION
CK9 Gun
Frequency range: 30 to
18 kHz.
Directional characteristic: lobe.
Sensitivity at 1 000 Hz: 1.1 mV/µbar (-59 dBV).
Equivalent noise level: 24 dB with filter CCITTC/DIN 45 405.
Weight net: 480g.
Dimensions: 610 mm long
x 23 mm diameter.
MANUFACTURER'S SPECIFICATION
C 451EB preamplifier
No-load amplification: 0.47 0.5 dB (feeding via 27
pF condenser and laod of studio amplifier
000
ohms).
Impedance, 20 to 20 kHz: X200 ohms.
Operating voltage: 9V dc.
Universal phantom powering: 9-52V dc.
Current consumption: X5.5 mA to DIN 45 596.
Frequency range: 5 to 30 kHz.
Bass attenuator built in: Flat or -7 dB at 50 Hz or
-20 dB at 50 Hz switchable.
Unweighted noise level: 3.6µV eff in flat response
setting.
Equivalent noise level: 21 dB weighted to CCITTC/DIN 45 450 in flat response setting.
Price: £38.90 for gun; £72.00 for preamplifier.
Manufacturers: Akustiche U. Kino Gerate G
mbH, A-1150 Vienna 15, Brunhildengasse 1,
Austria.
UK agents: AKG Equipment Ltd, Eardley
House, 182/184 Campden Hill Road, London W8.
f
Fig. 1 shows the frequency response of the preamplifier alone, when fed via a source impedance of
600 ohms in series with 27 pF, which is the nominal
capacitance of the condenser capsules. It is to be
seen that the response in the 'flat' position is
sufficiently flat over the audio frequency spectrum,
but in the two bass cut positions there is a little
boost just above the cut-off frequency. Whilst the
manufacturer does not mention this in the specification, it is probably a desirable characteristic;
however, it is noted that in the maximum cut position
the attenuation is less than that specified.
Because the preamplifier is only intended to
operate with the AKG series of condenser capsules,
it was not felt appropriate to measure other aspects
of its performance on its own for the purposes of this
review, and consequently measurements of noise
and gain were done for the complete microphone.
Noise of the complete system was determined as
an equivalent sound pressure level of 22 dB(A), with
the preamplifier set fora flat response. Such a performance is remarkably good and well within the
manufacturer's figures.
Sensitivity at kHz was found to be 0.95 mV for
74 dB spl (equivalent to 1 microbar) which is close
to the related sensitivity.
The frequency response performance, which is
shown for four different angles of incidence in fig. 2,
must be regarded with some caution, as the plots
were obtained under conditions that were not perfectly anechoic. However, the characteristics shown
reflect the general pattern of the microphone's performance where at zero degrees incidence the
frequency response is largely flat to greater than
16 kHz and a rapid but smooth fall -off in treble occurs
as the angle of incidence is increased. The front to
back performance was found to be very good over
60
STUDIO SOUND, JANUARY 1975
1
i3
Introduction
THERE HAVE BEEN many attempts to
produce the perfect ultra -directional microphone, otherwise known as gun, shotgun or
rifle microphone. Very few have been entirely
successful, though many have proved useful in
particular applications.
The gun microphone has become familiar
over the years in film work, where the microphone must be kept out of camera shot, in
television, in news reporting, sound effects
recording/broadcasting and more recently in
sound reinforcement. The majority of gun
microphones have been dynamic types, though
a number of capacitor gun microphones and
62
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61
® AKG CK9
FIG.1
50
PREAMPLIFIER
FREQUENCY RESPONSE
other highly directional devices have been
produced.
There have been several main approaches to
the ultra -directional microphone, including the
use of bundles of tubes of various lengths
ahead of the transducer, use of slotted tubes,
multiple apertures etc, to produce interference
and/or phase -shifts for sound coming from off
axis without effect, hopefully, on sound coming
along the axis of the microphone (see
Ro "ertson, `Microphones' (Iliffe) Ch.11, and
Burroughs, `Microphones: Design and Application' (Sagamore) p73 et seq). There have also
been a number of horn/lens arrangements, and
the parabolic reflector.
The AKG CK9 capsule, part of the CMS
modular range, is a capacitor type fitted with
a slotted interference tube, and has been
developed from a familiar professional cardioid
microphone capsule.
l0
30
d0
20
10
20
capsule, developed
from the more familiar CK1 capsule used in
the C451 and C452 microphones, was designed
for high directivity, independent of frequency,
in the smallest dimensions possible. It uses a
combination of interference and pressure
gradient principles.
At high frequencies,
directivity is achieved mainly by interference
between sound waves entering laterally through
holes along the length of the tube. At low
frequencies, directivity is obtained by a large
pressure gradient and phase shift; low frequencies have access to the rear of the microphone
diaphragm via three small apertures, a loading
cavity and the backplate of the capsule proper.
In fact, to simplify things a great deal, the CK9
appears very similar in construction to the
standard CK1 capsule with the addition of the
front tube and with three of the four sets of
apertures behind the diaphragm blanked off.
The result is an increase in directivity from
three for a cardioid to approximately ten
mid -band for the CK9-in other words, while
a cardioid would pick up about a third of the
random sound or reverberation that an omnidirectional microphone of the same axial
sensitivity would, the CK9 picks up only about
one-tenth at mid frequencies. The effect is to
enable the microphone to be used about three
times as far away from the sound source as
would be possible with a cardioid microphone
to maintain the same ratio of direct to indirect
sound, or that at the same distance the reverberation or indirect sound will be reduced by
a factor of approximately 10 dB mid -band.
In fact, according to the manufacturer's
curve, the directivity (y) drops to about five
at 150 Hz and rises to about 17 by 10 kHz.
This inevitably affects the quality or spectral
balance of the reverberation, and probably for
this reason the axial response has been tailored
somewhat so that the nominal response at
50 Hz is some 6 dB down on that at 1 kHz,
with the output rising gently to a maximum of
about 4 dB around 12 kHz, which not only
tailors the response nicely for intelligibility
over the speech band in unfavourable conditions but also balances to some degree the
reduction in discrimination at if and increase
in discrimination at hf. How much is deliberate
62
STUDIO SOUND, JANUARY 1975
100
200
500
1000
FREQUENCY
FIG. 2
Operating principles
The CK9 capacitor
50
2K
5K
10K
20K
Hz
--"
30
DIRECTIONAL
IN
RESPONSE OF CK9
20
30°
d6
G5°
10
010
FIG.3
20
50
00
200
500
FREQUENCY
000
IN
2K
5K
10K
20K
Hz
A -B POWERING FOR FLOATING OPERATION
L
MICROPHONE
R1=R2=18011
U
.
12V
C3. 500pF/15V
R3.
56011 FOR 24V OPERATION
and how much fortuitous only the designer
knows, but the result is undeniably satisfactory
in practice for most purposes!
It should be noted, however, that at 180°
the output from the CK9 at low frequencies is
actually greater than the 180° output from the
CK1 cardioid, owing to the introduction of a
small rear lobe in the characteristic (AKG
describe the characteristic as club -shaped); on
the other hand the mid/low frequency output
is some 6 dB down (nominal) at 45° to the axis
of the CK9, while this reduction in output is
not heard until about 90° with the CK1
cardioid.
It is normally assumed that the damping
materials and acoustic design of a highly
directional microphone of this kind will result
in a sensitivity on axis somewhat lower than
that of a cardioid of similar basic construction.
In fact the quoted sensitivity of the CK9 is
1.1 mV/Aar compared with 0.95 mV/µbar
for
the CK1, and the effective noise level is only
degraded from 22 to 24 dB (weighted).
Additional items
The amplifier supplied with the CK9 was
the C451EB preamplifier, which is marginally
quieter than the C452 amplifier, is phantom
powered from a supply of 9 to 52V and
incorporates a three -position switch with two
A
-B
AB Pearl
Mikrofon-
POWERING FOR UNBALANCED OPERATION
laboratorium.
bass -cut positions and one flat position. The
bass roll-off frequencies are 75 and 150 Hz, and
the positions give respective attenuations of
zero, seven and 20 dB at 50 Hz (manufacturer's
figures). The equivalent noise level of the
amplifier is degraded nominally by 1 dB in the
bass -cut positions. The 'E' version is XLR
compatible; a similar (`C') version is DIN
compatible. The battery unit has a 9V battery
and transformer to provide powering independent of the mains; a standard PP3 battery gives
a nominal operating life of 40 hours, and while
the consumption of the microphone amplifier
is only some 2 mA at 9V, any significant fall
in supply below 9V reduces the sensitivity.
remainder of the tube is the sheath for the front
part of the C451EB amplifier, which screws on
to the standard capsule mounting inside the
sheath.
This raises two of my few criticisms: when
the amplifier is screwed home, it is not possible
to alter the setting of the bass attenuator
without unscrewing the amplifier from the
CK9, thus temporarily disabling the microphone, and it is thus not possible to compare
instantly the effect of the attenuator in and
out. While this may to some extent be a good
thing in that it may discourage fiddling and
also prevent accidental operation of the switch
(though it would be quite a feat to operate it
accidentally, it is so small and well recessed),
Construction
if the switch has to be reset in the field it does
I must confess here and now that I regard mean unscrewing the unit, and consequent
the CK9, like the Sennheiser MKH815, as one extra wear on and risk of damage to the
of the most beautiful pieces of audio engineer- capsule thread. I can't say I am entirely happy
ing, visually, that are about. The CK9 is a
about regular screwing and unscrewing of that
long, slender matt -black tube, with a matt fine thread, having heard the odd unhappy tale
black end enclosed in a matt silver ring, and about damage to capsule threads in the past.
with a matt silver stripe running almost the One is not, however, obliged to unscrew the
full length. Into this fits the even more slender,
units unless one wants to alter the bass setting,
sand -blasted nickel -plated amplifier unit, about so the two could normally be set up as one
half of which projects from the tail of the unit and left.
CK9 to accept the connector. It seems a shame
A soft carrying case is provided, in addition
to obscure this elegant and yet totally to a rigid tubular transit housing, but the foam
unobtrusive design in a windshield
plastic which cornes round the CK9 will scarcely
Raptures over, down to facts. The CK9 accommodate the extra length of the amplifier,
incorporates a ceramic electrode and embossed though the case will at a (firm) push. The
metal diaphragm for stability with age, amplifier comes with its own padded and foamtemperature and humidity. The interference lined case. The CK9 also comes with its own
tube/capsule assembly is some 610 mm long,
axial response curve as measured by AKG.
23 mm in diameter. The interference apertures
The C451EB amplifier is 18 mm in diameter
(in the silver stripe) are three rows of square and 136 mm long overall (10 mm shorter in the
perforations of side 1 mm, over a length of C version). The amplifier, built around a
495 mm. The diaphragm appears to be situated
printed circuit panel running most of the length
at the end of the rows of perforations, and the of the housing, contains an fet bipolar impedthree rear apertures, each about 13 mm across ance converter driving a centre-tapped output
by 2 mm, are centred about 10, 14 and 18 mm transformer; this allows phantom powering via
behind the last of the interference holes. the two cores of the screened cable which carry
Behind these again are the factory -fixed retain- the balanced audio output. The amplifier also
ing grubscrews for the capsule, and the
64
!
DC21,
48 volt, cardioid, miniature.
Also available as omnidirectional DC20.
For further information on the complete
range of Pearl microphones, contact:
Allotrope
Limited
Wardour Street, London
90
W1V 3LE.
Telephone: 01-4371892. Telex: 21624,
U.K.
Representatives for:
AB Pearl Mikrofonlaboratorium -
Sweden, Microphones & accessories.
HES Electronics - Brussels, TSV
series telephone balancing units,
and studio equipment.
Inovonics Incorporated - Campbell
California U.S.A., Audio electronics.
Roland Zeissler Werk Für Elektro
Mechanik - Cologne, Racks and
instrument housings.
63
111
LOCKWOOD
SOUND TO REMEMBER
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Lockwood Loudspeaker Protec-
tion Device Model LPD developed
by M. Bradbury and S. Timms.
Protects any Loudspeaker against
Overload Conditions.
AKG CK9
contains a small hf oscillator and rectifier unit
to provide the necessary polarizing voltage for
the capsule; suitable filters to remove supersonic frequencies are incorporated in the output
from the amplifier.
Since the CK9 is part of the AKG CMS
range, it can alternatively be used with the
C452C or C452E amplifiers (DIN and XLR
respectively), which are designed for phantom
powering over a limited range of supply voltage
(40-54V) and take both amplifier supply (0.5
mA) and polarizing voltage direct from the
phantom supply. This makes the combination
less suitable for battery operation and hence
for portable or mobile work, however. Also,
the equivalent noise level of the amplifier is
nominally some 3 dB higher (weighted) than
that of the C451C or E, which may prove
troublesome when working well back from a
sound source or with quiet sounds. Mechanically the two amplifier versions are similar.
As mentioned earlier, the C451EB amplifier
supplied incorporates a switched bass attenua tor, which is useful in removing rumble and
handling noises, and wind noise, in mobile,
boom or outdoor applications. The switch is
set back in a narrow slot halfway up the body
of the amplifier; it must be adjusted by levering
with a fine screwdriver or similar implement,
and there are three distinct click settings as
well as clearly engraved markings. A tightfitting plastic skirt around the lever minimises
the risk of objects entering the amplifier
housing.
The inside of the amplifier case is threaded
at one end to accept the fine thread used on
the capsules of the CMS range; the other end
is fitted with the appropriate male XLR (or
DIN) fitting.
Performance
General
Tests were carried out over a period of
several weeks to assess subjectively the performance of the CK9/C451 combination, with and
without windshield, under a variety of conditions. A number of other capacitor microphones were used for comparative purposes,
and listening tests were carried out using
Spendor BC1 and other high-quality loudspeakers.
No operating instructions were provided,
but it was felt that the extensive information
provided by the data sheets accompanying
both CK9 and C451EB rendered further
instruction largely unnecessary. The battery
power unit supplied was used throughout and
was found very convenient to use, though it
is quite easy to forget to switch off at the
power supply if the microphone is not
disconnected after use.
Sound quality
LOCKWOOD
HARROW
-
MIDDX.
-
HAI 3AW
Tel. 422 3704 and 422 0768
64
STUDIO SOUND, JANUARY 1975
Sound quality was assessed both using live/
relayed comparisons and live/recorded comparisons on speech tests, and limited music
tests. Performance was assessed both indoors
and outdoors; outdoor assessments included
performance in windy conditions, under
moving and hand-held conditions, and with
and without windshield.
It came somewhat as a surprise to find just
how excellent the sound from on axis was,
with no concession to the microphone being a
special-purpose unit. Background hum and
hiss were always commendably low, and no
temperamental troubles were experienced even
on quite cold or humid days.
Speech
In all cases the reproduced sound was felt
to be exceptionally clean and natural. There
was a complete absence of sibilance, even when
speaking a few centimetres from the front of
the microphone (a condition unlikely to be
encountered in practice).
Fairly careful
positioning and aiming of the microphone is
necessary in view of the sharply directional
characteristic and the more rapid narrowing
of the front lobe at high frequencies than at
lower frequencies.
Used outdoors the reproduced sound was
very slightly `light' on both male and female
voices, probably a reflection of the slightly
rising overall response (according to AKG's
own measurements on the review sample the
response-with bass attenuator set flat-rose
gently by about 6 dB between 50 Hz and 1 kHz,
and a further 2 dB between 1 kHz and 10 kHz).
This lightness is not obtrusive, only apparent
by direct comparison with the live voice and
with relayed sound using a microphone without
this tilt in response; it adds considerably to
intelligibility under noisy conditions and to
my ears is much to be preferred to presence
bumps and the like. which can always be added
if required. Used indoors, or in reverberant
surroundings, the overall sound is nicely
balanced by this response tilt and the effect is
much less apparent.
The combination of a highly directional
characteristic and the excellent low -noise
properties of the microphone amplifier give a
remarkably quiet and clean signal even with
natural speech levels some way away from the
microphone; it is hardly an eavesdropper's
instrument, on the other hand.
Voice and guitar
As part of the limited music tests, recordings
and comparisons were made of a singer with
own guitar accompaniment in a fairly reverberant acoustic. Excellent results were obtained
with the capsule end of the CK9 about 2.5m
away from the performer.
The voice was
largely uncoloured and the character and
attack of the guitar were well maintained, while
the resulting recording sounded fairly dry; an
omnidirectional microphone used at the same
range produced a very live sound that verged
on bathroom quality.
With the microphone moved in to about
1.5m from the performer it became possible
to introduce substantial amounts of general
noise and disturbance in the room, other than
on the axis of the microphone, before pickup
of these sounds became obtrusive, illustrating
the potential of this microphone for reinforcement of performers without their being tied
to hand mics or obscured by stand mies.
66
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1"
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IVC 711P (P/C)
1"
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Will play 525 line 60Hz
tapes, 2 audio tracks,
stop frame, studio quality.
2 audio channels, stop, frame.
IVC 741P (P/C)
1"
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o
IVC 761P (P/C)
1"
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o
IVC 801PSM
1"
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o
IVC 821P
1"
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o
0
IVC 871P (P/C)
1"
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IVC 900
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0
IVC 100
1"
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o
o
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0
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Ikegami 321
Ikegami 321C
Ikegami 321L
4"
JVC KV 350
1
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IVC 705P (P/C)
cartridge
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High quality, 2 audio tracks,
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Assemble edit, 2 audio
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2 audio tracks, stop,
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2 audio tracks, stop,
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Insert edit, 2 audio, stop,
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Ultra high quality, broadcast
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2 audio channel high performance cartridge loading.
Remote control option.
Remote control option.
Remote control option, 12+
24 hours record.
Mechanical edit, built in
A
A
A
A
A
A
JVC KV360
o
(o)
o
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JVC PV 4500
r cassette
r cassette
JVC CR 5000
JVC CR 6000
National NV 3020E
National NV 3040E
National NV 3030E
National NV 1070
National NV 3082
I-"
National NV 5125
I" cartridge
National NV 3000
°t"
cassette
o
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o
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Shibaden 620 KD
Shibaden 612K
Shibaden
Sony CV 2100
Sony AV
Sony AV 3420
o
o
o
o
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o
o
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Sony CV 5600
Sony AV 3670
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Shibaden 610
Shibaden 610 KD
Shibaden 620
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Sony EV 320 CE
.1"
Sony VO 1200
j-"
cassette
o
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Sony VO 1810
rcassette
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65
® AKG CK9
Obviously there are limitations of movement,
and the 1.5m is about the closest distance
practical for this arrangement in order to
preserve the balance between voice and guitar.
Used closer on voice alone, the microphone
discriminated quite well against the guitar
(acoustic) provided the mic was inclined
upwards from in front of the performer so that
the soundbox of the guitar was towards the
least sensitive direction of the microphone at
low frequencies. In practice it is a little more
difficult to position the microphone for
reinforcement of the guitar as it becomes
rather hard to avoid changes in balance and
sound quality with movement.
Voice
As an extension of the above, tests with
close singing were carried out. No problems
or vices were encountered provided the singer
remained reasonably on axis and did not
approach closer than about 8 cm from the end
of the microphone. On -axis sound was slightly
light but otherwise clean and free from any
apparent nasties.
Musical box
In order to examine whether the CK9's complicated arrangement of tube, slots, damping
materials etc produced any nasty effects on
transient sounds, as from a musical box or
the like, comparisons and recordings were
made using a small musical box, with great
care that the reproduced sound was at the same
level as the original, and that in the case of the
recordings the A -B test was made with the
musical box and speaker in as nearly as
possible the same position in the listening
room; listening was carried out at various
distances. The results were quite remarkably
good and very much better than similar tests
with another less complex capacitor microphone. The sound was clear, bright and
without unnatural tizz or fuzz of any kind.
There were no reservations except that it is
most important that the sound should originate
on axis; at 10° off axis it was surprising how
the quality was `shaded'.
Piano
The piano is possibly not the first instrument
that springs to mind when considering applications of the gun microphone, but I felt it
would be interesting to see just how well piano
could be recorded (in mono) using the CK9, in
view of its satisfactory performance on other
material so far.
Apart from a slight lack of bass at the
bottom, quality was remarkably good. A
recording made at approximately 5m in a live
room sounded quite dry on replay, except right
in the bass where the fall in directivity was not
entirely balanced by the falling response, and
where raising the bass to compensate made
matters worse. However the exercise did show
just how good the results could be should the
need arise.
Birdsong
A number of outdoor recordings of birdsong
and other sounds, natural and unnatural, were
made. These included, as well as birds, the
sounds of active bees, passing helicopters, cars
STUDIO SOUND, JANUARY 1975
66
and aircraft, children at play, distant lawnmowers, telephones etc; in fact a fair package
of general sound effects.
All reproduced
convincingly; on a still day there was no need
for the windshield and with care handling
noise and transmitted rumble were minimal.
This and similar gun microphones are being
used for natural history recordings by a
number of professionals, particularly those
connected with natural history films; this is to
be expected in view of the excellent sound
quality obtained, the standard of construction
and pedigree of the instrument, and the ease
with which it is handled, quite apart from its
unobtrusive appearance. On the other hand
it must be remembered that many sounds in
nature are quite quiet, as too are distant
sounds such as cricket ball hitting stumps, so
signal-to-noise ratios can become a problem.
The background noise of the CK9/C451 system
is very low, but nevertheless there comes a
point where a distant sound is just too quiet
for a satisfactory signal-to-noise ratio to be
obtained.
A gun mic can discriminate against ambient
noise, but not against its own amplifier noise;
unlike the old parabolic reflector arrangement
there is virtually unity gain in the direction in
which the microphone is pointed, by comparison with the basic cardioid. At frequencies
where the diameter of a parabolic reflector is
substantially greater than the wavelength of
the incident sound, a considerable improvement
in the output results through focussing of the
sound on to the microphone, which can be an
omnidirectional or cardioid type according to
the relative importance of signal level and
narrow angle of pickup. Against this, there
are the disadvantages of poor directivity at
low frequencies and variations in frequency
and polar response at middle and higher
frequencies (Robertson-`Microphones', Ch.
11).
Nevertheless, there may be instances
where a good, quiet cardioid such as the basic
CK1/C451 combination, in conjunction with a
suitable reflector, may be more appropriate
where appearances can be traded for signal.
Polar response
Mention has already been made of the
apparent rapid fall in output off axis, and the
club -shaped design characteristic for the polar
response over a wide frequency range. Some
speech tests were therefore carried out to
supplement the observations under various
headings above with regard to the subjective
polar response over the speech band. These
were in turn supplemented with similar tests
using the musical box, which showed up rather
more easily the narrowing of the response lobe
at high frequencies.
At 15° off axis, the output from the musical
box was noticeably dulled; at 30° off axis,
speech and musical box were both down in
level, particularly in the extreme top.
At
angles beyond that it was easier to get meaningful results with speech than with the musical
box, which is fairly quiet in any case. Minimum
output in the speech band seemed to occur at
about 120° to the main axis of the microphone,
and output was still very well down át 180°.
Next, to investigate the effect of the interference slot on the polar response around the
microphone, it was mounted fairly low on a
stand, facing upwards from a well -carpeted
surface. The speaker then walked sideways in
a circle around the microphone, speaking at a
constant angle of about 45° to the main axis.
Taking the interference slot as reference, the
top apparently reached a maximum at about
180° to the slot, ie with the interference slot
out of sight behind the microphone. The effect
was slight, however, and I would doubt very
much that it would ever be of much
consequence.
Popping
The popping problems associated with some
microphones on close speech or singing are
unlikely to be encountered with this one if only
because of its likely uses. A possible exception
is during radio or television interviews in a
crowded area, where the gun mic might be
held over the heads of the crowd towards the
interviewee and might either accidentally be
swung too close or come close to some other
speaker (it would be very bad policy to use the
microphone within a few centimetres of a
person in the majority of sound reinforcement
applications). It was found that close speech
at about 5-8 cm from the front of the tube
would produce some popping, but the problem
is completely removed by use of the windshield
and is very unlikely to be a serious one.
Wind noise
The microphone was used successfully out
of doors on a calm day without the need for
windshield or If filters. A moderate breeze
caused some noise, however, and a strong wind
a fair amount of blasting, as is to be expected.
AKG supply a polyurethane foam windshield
(type W19) which covers almost the full length
of the CK9 and offers a claimed attenuation of
20 dB to wind noise. They also supply and
recommend the Rycote windshield (see below),
designed for use with the CK9 and similar
slimline gun microphones; this proved entirely
successful in coping with all winds at our test
site.
Handling noise
On the whole the microphone proved relatively free from handling noise, though
handling was much improved by the compliant
mounting in the Rycote windshield.
The
attenuation of rumble and bumps was helped
by the use of the 75 Hz filter, without seriously
degrading the response.
The rubber handgrip H7 may also be used
to reduce handling noise in conjunction with
the windshield or a fixed stand grip for the
microphone.
Bass filters
The C451EB amplifier supplied with the
CK9 was the version incorporating switched
bass filtering from 75 and 150 Hz, giving 0, 7
and 20 dB attenuation at 50 Hz in addition to
the design attenuation of low frequencies.
Most listening tests were carried out with
the switch in the flat position. The 75 Hz turnover position was found useful in reducing
handling bumps and rumble, without affecting
speech quality; it did not cope significantly
with wind rumble, for which the 150 Hz setting
was better and the windshield very much better
still. Obviously the 150 Hz position could be
useful under adverse conditions of If noise and
rumble, but where possible the 75 Hz setting
would be preferable if the flat setting cannot
be used. If the switch, which is obscured by
the end of the CK9 tube, is to be left set, I
would feel inclined to position at the 75 Hz
turnover for general use as a compromise, as
the 150 Hz setting normally makes speech
sound a little thin. Obviously this is a matter
for personal experiment, however, and for
musical purposes the bass loss would have to
be borne in mind; on the other hand for bird song recording etc the bass loss could be an
asset in reducing distant traffic rumble etc
from the outset.
An external bass filter type KF lE (-30 dB at
30 Hz ref 100 Hz) is also available.
Residual noise
To those who know the C451 family of
microphones it will come as no surprise that
the background noise of this combination is very
low and allows considerable flexibility in use.
Moreover, regardless of noise measurements
and weighted/unweighted figures, the microphone sounds quiet-what hiss there is, is
smooth and its spectrum makes it unobtrusive.
No hum problems were encountered, even
when using the output unbalanced. The source
impedance is below 200 ohms, and long
balanced leads may be connected without
problem. It is very unlikely that distortion
would ever be a problem.
Summary
The CK9/C451 combination gun microphone
is a beautifully made and finished design. It
produces sounds of a very high quality, with
low background noise levels as well as low
ambient noise levels. The axial frequency
response is smooth, and the slight rise from
extreme bass to the top end, some 8 dB in all,
produces the effect of a clear and balanced
sound in conditions of high ambient noise or
reverberation without making the instrument
Its speech
unusable for music purposes.
performance is particularly good. The microphone offers a high degree of discrimination
against off -axis sounds, and though this
discrimination is not wholly independent of
frequency the polar response is well maintained
over a wide range; discrimination is considerably better than on many earlier and present
designs of gun microphone and the deficiencies
are to some degree mitigated by the slight tilt
of the axial frequency response. In conjunction
with the other accessories available, the CK9
is a most useful component in the CMS range
from AKG and offers great flexibility in use.
In addition to what one might call the traditional uses of the gun microphone-hand-held
outdoors, boom -mounted indoors and outhigh quality gun microphones are now being
used in high quality sound reinforcement and
for stage pick-up in the theatre, where it may
be necessary to place a microphone by the
edge of footlights or even in the pit while
discriminating against nearby (orchestral)
sounds. On the strength of my own experience
with this microphone, I would expect this to
be a growing use of the gun mic where-as in
this case-the microphone's performance will
enable this to be done satisfactorily. The CK9
has the bonus of being inconspicuous, and
beautiful if you do spot it.
unit
The B46E is a small, solid, matt -nickel
finished unit, approximately 35 mm square by
114 mm long (142 mm including XLR female
termination), with a captive screened-twin lead
providing a balanced output via an isolating
transformer. The transformer is centre-tapped
on the input side to provide 9V phantom
powering for the microphone via the balanced
signal leads and the microphone output
transformer. There is a recessed slide switch
in the case, to switch the supply on and off,
with an engraved red dot for 'on'. A single
large non -captive bolt, which can be turned
easily with a Zp piece, enables the inner part
of the unit to be slid out to exchange the 9V
PP3-type battery or equivalent Mallory
TR146X cell. The battery supply is decoupled.
A similar unit designated B46C is available
with DIN connector for use with the appropriate leads and amplifier. The unit is intended
to supply one microphone only.
B 46 Battery
Rycote windshield
The Rycote windshield intended for use with
the CK9 assembly is a long, white sausage shaped affair, fitted with a detachable handle.
Externally, the windshield is made of a stiff,
coarse white plastic mesh, with large spaces
between the cross -members of the mesh. The
two ends are rounded, and the hemispherical
ends are coupled to the long tubular section
with grey plastic rings. The ring at the tail end
of the shield is split, and a cunning hole -and pimple plus velcro tape arrangement allows
the end to be removed and replaced easily in
order to fit the microphone inside; there is a
small double slot provided for the microphone
cable to emerge through this ring, and the
cable is gripped quite well by this arrangement
when the microphone is in position. Inside,
there is another reinforcing ring at the middle,
and the inside of the plastic mesh is lined with
thin white brushed nylon or some similar
material. A reinforcing strip of plastic along
part of the length of the shield carries the bolts
for fastening the detachable wooden handle,
as well as the compliant rubber mountings for
the nylon grips that hold the microphone.
Slipping the microphone in and out of these
is quite easy once the knack is acquired. The
microphone is positioned so that neither the
front nor back of the CK9/C451 unit rubs on
the fabric at the end of the windshield.
In use the windshield was found to be completely effective in moderate winds and when
swinging the microphone unduly rapidly.
Unfortunately, there were no gale -force
winds during the period of test. The windshield also helped cut down handling noise and
rumble considerably, because of the compliant
mounting inside.
However the varnished
wooden handle did give rise to some scuffing
noises, which were completely eliminated by
using the AKG H7 pistolgrip, for which the
end of the wooden handle carries a threaded
insert. The balance of the combination is good
for easy handling and rapid pointing and, if
anything, is improved by use of the H7 as well.
Comparative tests were tried with the windshield on and off the microphone, to see
whether there was any detectable affect on
sensitivity or frequency response. The effect
on speech was very subtle, if any, and I would
strongly recommend the use of the Rycote
windshield with the CK9 for outdoor or handheld use.
68
Teknik 27s Graphic Equaliser
THE
ULTIMATE
IN TONE
CONTROL
Klark Teknik, Summerfield, Kidderminster DYE 7RE
Telephone: Kidderminster 64027
67
AKG CK9
evaluation have been dealt with in the body of
the field trial, and I shall confine myself here
to brief descriptions.
Accessories
H7
The use and performance of the various
accessories supplied with the CK9/C45IEB for
The H7 pistol grip is intended for use in
conjunction with the CK9 and either the Rycote
SENNHEISER
MKH 815T
that the microphone amplifier being used is capable
of handling such a high level without overload; if
necessary attenuators can be inserted in the microphone line without excessive loss in signal to noise
ratio.
As shown in fig 1, the microphone's impedance is
less than 20 ohms between 500 Hz and 20 kHz, so
capacitive loading by very long microphone cables
will have negligible effect upon the frequency response, the recommended microphone amplifier
input impedance being greater than 200 ohms.
The noise performance of the microphone was
found to be extremely good, the equivalent sound
pressure level of the internal noise being only 22
dB(A). Taking into account the high sensitivity, this
means that very good noise performance can be
achieved even if rather poor microphone amplifiers
are used!
Instead of plotting a polar diagram of the frequency
response, fig. 2 shows the response on axis, and at
three different angles off axis. These curves were
obtained under conditions which were not perfectly
anechoic and must therefore be treated with some
caution; however, they do show the pattern of the
microphone characteristics. It is to be seen that on
axis the microphone has a rising characteristic at
high frequencies which believe to be a desirable
characteristic for a gun microphone, and also a fall
off at very low frequencies which was found to make
the microphone very tolerant of 'handling noise'.
A very rapid fall -off occurs at middle and high
frequencies with mild orientations off axis with a
pronounced dip around 6 kHz, but provided that the
microphone is aligned within say ±15° this does
not present any problem.
Finally, on the powering side, the microphone current drain was found to be 5.7 mA into the DIN
standard power arrangement of two 180 ohm resistors being fed by 12V. This requirement is met by
such recorders as the Nagra /V, and for other applications Sennheiser manufacture a variety of
powering devices.
By John Fisher
Pistol grip
windshield or the AKG SA70/3 stand adaptor.
The pistol grip is moulded in a semi -flexible
rubbery material, which reduces the transmission of rumble and bumps, and produces less
finger movement noise than the wooden handle
of the Rycote windshield does without the H7.
The finish is matt black. A useful extra.
I
THE TESTING OF the microphone was necessarily fairly basic, for as with other electroacoustic
transducers there is always some doubt as to what
extent the measured results correlate with the subjective performance. The sensitivity was found to be
5 mV using the DIN standard powering arrangement
for a sound pressure level of 74 dB spl at 1 kHz
(equivalent to 1 microbar) which is within the upper
limit of the manufacturer's specification allowing
for measurement errors. Because of this high sensitivity the microphone is capable of delivering up to
half a volt at high sound pressure levels, so considerable care must be exercised to make certain
MANUFACTURER'S SPECIFICATION
Studio directional microphone
Connector socket: 3 pin standard to DIN
(Type MKH 815 T -U
:
3
floating.
41
524.
pin Cannon XLR3.)
Dimensions: 19 mm dia,
Weight: approx 370g.
550 mm
Nominal load: + 7200 ohms.
Signal to noise ratio to DIN
Hayden House,
Bucks.
45 590
ref
1
17
Chesham Road, Amersham,
N/rn2:
74 dB.
long.
Frequency response: 50 to 20 kHz
Operating principle: interference line.
Directional characteristic: lobe.
Sensitivity at 1 000 Hz: 4 mV/µbar f1 dB;
Hugh Ford
40
mV/,
Pa ±1 dB.
Impedance: approximately 20 ohms symmetrical
68
STUDIO SOUND, JANUARY 1975
Maximum sound pressure level: 150 µbar.
Operating voltage: 12 ±2V.
Current drawn: approx 6 mA.
Temperature range: -10°C to +70°C.
Manufacturer: Sennheiser Electronic,
Bissendorf/Hann, West Germany.
UK distributor: Hayden Laboratories
Introduction
3002
Ltd,
THIS MICROPHONE CAME for review at
the same time as another gun microphone, the
AKG CK9/C451EB combination from their
modular range of capacitor microphones. To
avoid unnecessary repetition may I refer the
reader first to my general introductory remarks
in the field trial of that microphone.
An earlier Sennheiser gun microphone design
is described in some detail, along with others,
in A. E. Robertson's standard work 'Microphones'; it was a moving coil type, some
200 cm long. Another design, by Western
Electric, was some 150 cm long, and it is
interesting to see how a similar or better
directivity, coupled with other improvements
in performance, has been achieved in much
smaller dimension:. in the current generation
of gun microphones, following the general
trend with microphones as a whole.
FIG.1
01V
MKH 815T
10
on
IMPEDANCE
511
Operating Principles
Like the AKG gun microphone, the
Sennbeiser MKH815T uses a capacitor capsule
as the transducer, and an interference tube to
increase the directivity. In other words, a
slotted tube is coupled to the front of the
capsule, and while sound entering from
straight ahead passes down the tube largely
unimpaired, sound striking the microphone
from the side enters via the various apertures
along the length of the tube and arrives at the
capsule out of phase with sound from the
same direction which has entered the front of
the tube; the result is a cancellation or interference between these out -of-phase waves and
a reduced or zero output. The effect is
dependent on angle and frequency, and at low
frequencies the microphone is increasingly
dependent on sound reaching the rear of the
diaphragm to provide directivity, as in a
conventional cardioid design. The general
effect is to produce a single large lobe in the
direction in which the tube is pointed; the lobe
becomes narrower at high frequencies but
pickup from the rear may also increase. The
aim is normally to provide high directivity over
the speech band at least.
In other respects, however, there are a
number of interesting differences between the
AKG and Sennheiser designs. The Sennheiser
is not modular; designed as a single unit with
transducer and amplifier in one housing.
Furthermore, unlike the AKG design which
uses an fet front end and a dc polarizing
voltage, the Sennheiser microphone uses rf
techniques to obtain the audio output, allowing
the voltage across the capsule to be kept down
to some 10V ac, with a number of obvious
advantages as regards humidity, etc, as long as
the rf technique is as good as the fet amplifier in
other respects such as noise level and linearity.
The Sennheiser circuit uses an 8 MHz crystal
controlled oscillator, which feeds a discriminator tuned by the capacitance of the capsule.
The resultant audio output is amplified,
buffered and filtered. The output impedance
of the amplifier is low, which makes for noncritical impedance matching, and the output
is at a rather higher level than is normal with
professional capacitor microphones; it can
indeed be used (unbalanced) to feed the
auxiliary input of a Revox recorder.
There have been two schools of thought
about the use of rf circuits in capacitor microphones. One advocated rf circuits because
with careful design and adjustment they
offered low noise levels and avoided some of
the problems of high -voltage, high -impedance
circuitry; the other complained that the stability
of the circuits, particularly under tv lights and
in hot, humid atmospheres, was not good
1011
0 01V10
20
50
100
200
enough to ensure that satisfactory performance
was maintained. Doubtless the inclusion of a
crystal oscillator indicates that some care has
been taken to provide the necessary stability.
It would be very difficult, however, in a field
trial of this kind, to simulate accurately and
adequately over a sufficient period the adverse
conditions under which such a microphone
might be used; beyond saying that no problems
were encountered in the course of testing, no
comment can be made or should be implied
from this field trial on the long-term performance of the circuitry under extreme conditions;
nor should this caveat be taken as implying
that the microphone will not be satisfactory
under those conditions.
The use of rf techniques rather than the
conventional high impedance input removes
the need for a very -high input impedance
amplifier, removes the danger of arcing as the
voltage applied to the capsule is low, removes
the tension on the diaphragm due to the
polarizing voltage on a conventional capsule
system, removes the need for special high -value
resistors and low-noise fets or nuvistors in the
amplifier circuits, and keeps impedances in the
amplifier low; the floating supply system
removes the need for an output transformer
while allowing the do supply to be carried by
the twin audio leads in a similar way to
phantom powering, but without a dc flow
through the screen (which has been known to
cause noise on certain microphones).
1000
500
FREQUENCY
IN
2K
5K
10K
20K
H
It should be noted that the A-B powering
technique used by the Sennheiser is not directly
compatible with phantom powering; a number
of readers may be more familiar with phantom
powering than A -B powering to DIN 45 595,
and accordingly the method of connection for
floating and unbalanced inputs is shown in
figs. 1 and 2 respectively.
Alternatively, a battery adaptor type MZA
6-2 is available; this takes a stack of nine
Mallory RM 625 mercury cells and screws
directly to the output connector of the
MKH815T; a similar unit is available for
connection to the Cannon terminated version
of the microphone; other units available are
two mains supplies, a matching unit if filter
for connection to Nagra inputs, a rumble filter
unit and an adaptor for powering from 12-48V
phantom supplies (MZA 56 P -O and MZA 56
P-U for DIN and Cannon XLR versions
respectively). None of these units was supplied
with the review microphone, but I would expect
the battery unit to be a most useful extra for
mobile work.
Construction
The MKH815T is visually a very beautiful
piece of engineering. It is slightly slimmer and
shorter than the AKG gun microphone, partly
because of its integrated design.
Sound enters the front of the interference
70
k.
69
® SENNHEISER MKH 815T
was assessed in both still and windy conditions,
stand mounted and hand held.
The general impression was of a slight lack
in bass, combined with a noticeable rise in
output at high frequencies; the sound produced
was very acceptable under adverse conditions,
but given better conditions the sound of the
CK9 unit was felt to be a more natural balance
and to be preferred. The output from the
Sennheiser could of course be `tamed' externally by an active or passive unit to reduce the
hf output if desired, and this. would have a
small bonus in reducing the hf content of the
residual noise of the microphone.
tube via slots machined into the cylindricalconcave end of a metal plug that closes the
interference tube. The interference tube and
amplifier housing appear to be in a sand-blasted
nickel finish that is elegant without being
highly reflective; there should be little or no
problem of reflections of studio lights if the
microphone appears in -shot, and it should be
largely unobtrusive in reinforcement or similar
applications. The tube is just under 55 cm long
and 19 mm in diameter, and the interference
apertures, a series of closely -spaced slots some
11 mm across the chord, run in a line down
Speech
the length of the microphone for about 45 cm.
As with the AKG gun unit, particular attenThe slots are backed by a very fine metallic tion was paid to speech tests, for the same
gauze, which is too fine to allow one to see
reasons.
what is inside. The transducer diaphragm
The sound was always clean and clear, with
appears to be about 6 cm from the rear of this a slight incisive edge which was more apparent
row of apertures, towards the front of the on some voices than others. Female speech
microphone, so sound entering the rear of the tended to show an emphasis of consonants, in
microphone capsule does so by a similar but particular sibilants, more than male speech.
shorter interference tube. The space behind The effect was of a slight brightness and sparkle
the capsule also appears to contain parts of on speech which sounded artificial by comparithe amplifier circuitry, though the gauze
son with the original, without the harshness
prevents clear sight of what is there. A single associated with the presence (or inherent)
grubscrew retains the internal assembly in the bumps in the response of certain microphones.
casing, and the male DIN connector is suitable The hf rise is certainly more steep than the
for use with a threaded (not bayonet) locking slight rise or tilt found with the AKG microconnector.
phone, and bears out the manufacturer's pen
The sensitivity may be adjusted by altering trace which indicates a rise in response of
the nominal values of a fixed attenuator which
approximately 2 dB at 5 kHz and 7 dB at 8-15
precedes the buffer transistor of the head kHz; I have seen no measurements to confirm
amplifier; values are specified in the instruction these figures, at the time of writing, but
booklet (which contains a circuit diagram) for fiddling with tone and filter controls suggests
sensitivity adjustment by ±1 and 2 dB.
that the figures are of about the right order.
The slight fall in bass response was not
Performance
generally noticeable on male speech, particuGeneral
larly in noisy or reverberant surroundings;
Tests were carried out over a period of with the hf rise approximately removed,
the
several weeks to assess subjectively the per- sound quality on speech was
almost indistinformance of the MKH815T as a highly direc- guishable from that obtained with the
CK9.
tional microphone, under a variety of conditions. Other capacitor microphones were used
Musical box
for comparative purposes, including the AKG
Direct comparisons and recordings made
CK9 unit; listening tests were carried out using with the aid of a small musical box were quite
Spendor BC1 and other high-quality loud- revealing in some respects. On axis the sound
speakers.
was slightly over-sharp, `ticky' or `white', to
A small booklet accompanied the micro- use some very subjective descriptions. Off-axis
phone in its padded wooden case, and provided the sound of the musical box was rapidly
all the necessary information with regard to
muffled as the angle relative to the axis increapowering and connection; the microphone is sed; the fall in top was noticed at about 10-15°
supplied with its own axial frequency response
off axis and the sound was distirctly muffled
curve as measured by Sennheiser. On the
by about 45°, by comparison with what it had
review sample the hf response in the 8-15 kHz
been and with the original.
region, as measured by Sennheiser, appeared
Once again the on -axis sound could be made
to be just outside the manufacturer's specified more nearly like the original by approximately
tolerance for rise in output in this region; removing the hf rise with tone and filter
similarly at the if end the bass roll -off started controls, though the improvement was less
earlier but was better maintained at the extreme easily detected than with speech; the remaining
than implied by the manufacturer's published differences between the original and reproduced
nominal curve (though measuring conditions
sound were quite subtle, however, and must in
are likely to influence the if readings in particupart be due to other links in the reproducing
lar). The general sound produced by the
chain.
microphone suggested that there was indeed a
definite rise in output at high frequencies, and
Music tests
while this gave a clear sound it was not always
Limited music tests were carried out using
quite as natural as sound obtained with other singer with guitar, piano, and voice alone.
microphones, among them the CK9 gun mic. Both guitar and voice acquired an edge or
brightness that was not characteristic of the
Sound quality
original; it would be perfectly acceptable in
Quality was assessed using live-replayed many folk or pop music recording contexts, and
comparisons and live-recorded comparisons on is not necessarily a criticism of the microphone.
speech, and limited music tests. Performance
It is mentioned here as a pointer to the kind of
70
STUDIO SOUND, JANUARY 1975
sound quality to be expected from an uncorrected microphone of this kind; it must again
be said that this edge was not one that would
be likely to prove objectionable or particularly
obtrusive, but it does show up on direct
comparisons with the original. Unlike the
sharp peaks in some moving coil microphones,
it is the kind of smooth and broad rise in
response that can if necessary be at least
partially corrected if such correction is not
considered bothersome in the original choice
of the microphone.
In other respects voice and guitar reproduced
well, and a respectable balance of both was
obtained at about 2.5m in fairly reverberant
surroundings; when the capsule part of the
microphone was about 1.5m away, about the
closest that would give a reasonable balance,
the microphone was reasonably tolerant of
noise and disturbance from well off axis.
A singing voice on its own again showed up
a slightly husky edginess.
No particular
problems were encountered with the singer on
axis, provided the singer kept at least 20 cm
from the end of the microphone. Puffs of
breath produced quite bad popping at closer
ranges. No distortion problems were encountered, but it is quite easy to run into microphone
amplifier distortion at the mixer or recorder in
view of the relatively large output from the
microphone-again, it is easy enough to
attenuate the output
Piano reproduced quite respectably via the
MKH815T; it was felt preferable to tolerate
the slight loss of lower bass rather than
accentuate the reduced if discrimination in
reverberant surroundings.
!
Outdoor sounds
In addition to speech tests undertaken out
of doors over long absorbent grass (my best
excuse yet not to cut the paddock) recordings
were made of birdsong, insects, the sounds of
trees in a gale, passing aircraft, cars, etc. All
were well reproduced and many proved quite
convincing. No peculiarities or vices were
revealed, and the microphone handled well.
Polar response
Mention has already been made of the
microphone's ability to discriminate against
unwanted off-axis sounds, and of the more
marked loss of high frequencies off-axis. The
polar response was investigated a little further
using speech and musical box tests. Comparisons were also made between the performance
of the Sennheiser and AKG gun microphones.
The overall impression was that the directivity of the MKH815T and the CK9 were fairly
similar; if anything the Sennheiser is slightly
less directive than the other, but we found it
difficult to be positive on this score, and no
doubt slight differences in the respective
microphones' polar patterns at different
frequencies would account for this uncertainty
and give conflicting impressions on different
kinds of programme material.
At 10-15° off axis little change was noticed
on speech, but a just perceptible loss of high
frequencies was noted when testing with the
musical box. At 30° off axis a signal fall off
was noticed on both speech and musical box;
output was appreciably down by 45°, the
musical box sounding quite distant, and
rejection between 90° and 180° was very good.
Allowing for the slightly greater output at
high frequencies on the MKH815T than the
AKG CK9 (on axis), the sound quality and
directivity appeared fairly comparable; the
main difference if any appeared to be at around
30° to the axis, where the fall-off in hf seemed
more rapid on the Sennheiser than the AKG,
but where the AKG seemed marginally more
discriminating across the speech band. In
other words, the Sennheiser microphone
appeared to give a very slightly broader angle
of acceptance for speech than did the AKG,
with a slightly more rapid initial fall in output
at high frequencies than with the AKG at
angles off the axis, and a more noticeable
change in quality from the extra brightness on
axis to the restricted response off axis. At low
frequencies the directivity of the two makes of
microphone was subjectively similar.
To assess the effect of the slot on the polar
response of the microphone about the main
axis, the microphone was mounted on a stand
pointing upwards, and speech tests were carried
out with the voice moving in a circle around
the microphone. There appeared to be little
variation in speech quality, except that on
sounds coming from directly behind the interference apertures-that is, with the apertures
out of sight for the person speaking-there was
a reduction in top, just enough to dull the
sound slightly; curiously, this seemed to be the
opposite effect to that noticed when a similar
test was carried out with the CK9 gun tube.
The head of the person speaking made an angle
of approximately 30° to the microphone;
insufficient tests were carried out to ascertain
whether the effect was maintained or reversed
at slightly different angles, and since it was
relatively slight and unlikely to be of too much
consequence in practice, I would not attach
too much weight to the importance of this
observation, mentioning it only as a matter of
interest.
Bass filters
The bass response of the microphone is
fixed, and falls slightly below 150 Hz, with no
adjustment provided on the microphone. As
mentioned earlier, a plug-in attenuator for use
between power unit output and mixer/amplifier
input is available, giving a reduction of
approximately 6 dB at 100 Hz and 15 dB at
50 Hz. Lf filters are also incorporated in the
adaptors available for connecting the microphone directly to Nagra inputs. In practice it
was remarkable how well the microphone
handled and behaved out of doors without
additional filtering at low frequencies.
noise ratio obtained must be of about the same
order, there is slightly more high frequency
output in the hiss from the MKH815T than in
the hiss from the AKG microphone, and this
makes it that little bit more noticeable. However, the noise performance of both microphones is very good and the higher signal level
from the MKH815T could certainly be an
advantage in some cases; on no occasion during
music or speech testing was there any apparent
distortion from the sound levels encountered,
and one is unlikely to be recording trumpets
at a few centimetres range with this kind of
microphone.
Ambient noise
Ambient noise levels achieved, in and out
of doors, were good confirmation of the
directivity of the microphone, and the noise
itself seemed reasonably balanced in spectrum.
Out of doors the ambient noise is of course
dependent on the direction in which the
microphone is facing-quite an amount of
rustle may be picked up when the microphone
is pointed towards trees, near silence when
pointed towards the sky, and this produces
quite marked changes when following a bird,
for instance.
Popping
Please refer to my comments on this in the
CK9 review. Checks on popping were made
with the MKH815T. Speech very close to the
capsule proper could produce popping, and
speech at moderate levels some 6-8 cm from
the front of the interference tube also caused
it. This became very severe at 3-5 cm from the
front of the tube, and the effect was much
more violent at the closer range than when a
similar test was carried out with the CK9 for
comparison. Use of the windshield should
eliminate most such problems, but of course
the slim lines are lost.
frequency rumble, but at quite a low level,
much lower than most ordinary cardioids
would produce under those conditions, and
very much lower in level than produced by the
AKG gun mic under those same conditions.
There had been no convenient gale at the time
of carrying out the windshield tests on the
CK9, but when the fruit started flying off the
trees during the typing of this report I seized
the opportunity of a little more testing.
Recordings made with the MKH815T, without
windshield, were perfectly intelligible under
these conditions and could probably have been
cleaned up satisfactorily with a steep high-pass
filter, while recordings made at the same time
with the CK9 unit were so badly blasted as to
be totally unintelligible and to cause anxiety
for the welfare of the listening loudspeakers !
A windshield would obviously have improved
things considerably for both microphones (rain
stopped play) but I was very impressed at the
unshielded performance of the Sennheiser
microphone.
Sennheiser can supply a foam windshield
(MZW 815) or a windshield which appears to
be similar to the Rycote one supplied by AKG
for test with the CK9; Sennheiser state that
their version of the latter (MZW 804) is water
resistant, and claimed reduction of wind noise
is 26 dB as against 16 dB for the foam type.
Pistol grips and shock mounts are available
for use with the microphone and windshields,
but neither windshields nor mounts were
supplied for review with the microphone.
Handling noise
Even without the shock mounts which are
available, the MKH815T handled remarkably
well, with a minimum of thumps, rumble and
chuffing. As on wind noise, it scored over the
AKG microphone on these counts. Ideally,
though, one would use one of the compliant
shock mounts, but in an emergency a reporter
could use the microphone as it stands.
Wind noise and movement
Perhaps one of the most outstanding features
of the MKH815T appeared to be its good
behaviour in wind and when moved violently;
it would tolerate being swung through the air
much more rapidly than I can imagine any
sane boom operator doing, and when taken
out into a gale that removed branches from a
large beech tree the microphone behaved quite
remarkably well: true, there was some low
Case
The microphone comes in a rigid, padded
and lined case with a hinged lid; a piece of
foam or the like is necessary to stop the
microphone sliding up and down the recess,
which is the full length of the box. The case
is not really designed to accommodate% lead.
While it provides quite good protection for the
72
Residual noise
The background noise was found to be very
low. Because of the relatively high output level
from the microphone, noise in the input
amplifier of the recorder or mixer used with it
p
o
7
is unlikely to prove troublesome. No hum or
rf breakthrough problems were encountered
during the tests, and the absence of an output
transformer in the microphone may help avoid
possible problems of induced hum.
Very rarely was background hiss apparent,
except when using the microphone for capturing birdsong or the like on certain occasions.
It is not easy to say whether the residual noise
level of the Sennheiser MKH815T or the AKG
C451/CK9 combination is lower, when due
account is taken of levels and matching, but
my impression is that though the signal-to-
Thursday June
19,
Friday June 20
MANUFACTURERS OF PROFESSIONAL
RECORDING EQUIPMENT APPLY
FOR EXHIBITION SPACE NOW.
23
E. L. MASEK Secretary
Chestnut Avenue, Chorleywood. WD3 4HA.
71
SENNHEISER MKH 815T
microphone in transit, the hinges are a little
flimsy and one had come adrift by the time the
review microphone had done its rounds and
reached me. This is a minor detail on an
otherwise well finished and produced article.
Summary
In appearance the microphone is extremely
elegant, small enough not to be conspicuous,
and is beautifully finished.
It produces high quality sounds with low
background noise levels and low ambient noise
levels. Although there is some emphasis of
extreme top, the sound is clean and the
spectrum of the indirect sound picked up is
subjectively well balanced.
For naturalness of sound, I would not
consider the MKH815T quite the equal of the
RADIO MANCHESTER
another string of offices with double-glazed
windows looking out over the traffic below.
One can imagine with a shudder the sound
leakage problems that would have arisen if
Piccadilly Radio had been put together in a
four-month rush like the London stations,
without time to think out the best way of
isolating the studios from the noise of the
outside world.
Like Capital, Piccadilly Radio has no
shortage of exciting plans for the future. The
portable Neve PSM 12-2 used for outside
broadcasts will be built into Control Room 2
and a new mixer brought in for the new studio
intended for home-grown jingle production.
Also a new portable desk is being designed for
permanent availability on outside broadcasts.
This will be ganged with a discotheque system
SCHOEPS CMT
36-{-56
different situations. We would suggest that
other studios would also find a lot of interest
in trying different mics. All of the mics
compared here are of very high quality indeed
and one has little if anything to lose in trying
something new. They are all in the same price
bracket, and all have their fortes-the Neumann
U87 for brass and percussion, the AKG C414
AGONY COLUMN
Following the normal routine, it was
requested that a reference acetate be cut of the
new album by a rising superstar; the tapes had
appeared from America and were awaiting
processing. The afternoon was boring, and a
fairly dubious lady singer's album was lying
around in line for similar treatment. The
lathe's varipitch was not working, although
fortunately when this happened (often) the
resulting grooves were very steady and certainly
72
STUDIO SOUND, JANUARY 1975
AKG microphone on two scores: the substantial rise in hf output, and the apparently slightly
more directional characteristic of the
MKH815T than the CK9 at the highest
frequencies. On the other hand it must be
pointed out that the hf rise on axis can at least
be reduced to perfectly acceptable amounts for
purist purposes by external equalization; for
many purposes the response would be perfectly
acceptable and perhaps desirable as it stands,
and over the range of frequencies that are
important for intelligible speech the angle of
pickup appears to be very slightly greater than
that of the AKG microphone, which could
have advantages in certain situations. The
noise performance was considered similar to
that of the AKG microphone subjectively with
possibly a slightly more toppy hiss from the
MKH815T.
In terms of flexibility, the AKG microphone
scores on the grounds of its modular construction, but for many people this may be balanced
by the better wind and handling performance
of the Sennheiser. With the appropriate windshields there should be little to choose between
them normally, but the Sennheiser seems
basically more immune.
I would not attempt to pick a `better buy'
from these two microphones-and there are,
after all, a number of others to be considered
when shopping around--since the gun microphone is a specialist microphone and it is the
specialist's particular needs that will, or should
be allowed to, dictate the final choice. It can,
however, be fairly said that where a highly
directional microphone is required, whether
for hand, boom or fixed use, indoors or outdoors, for film work, sound reinforcement or
sound gathering, this microphone should be
considered as a serious contender.
of broadcast quality so that Piccadilly DJs can
go out to local halls and clubs and broadcast
live disco sessions. An extensive range of
portable Uhers, radio telephones, uhf walkitalkies and a radio car mean that if the Bomb
drops on Manchester, it will be well covered
by Piccadilly. If the worst comes to the worst,
a reporter can phone in from a call box and
be punched through to one of the holding lines
on the studio control desks.
After a month on the air, Piccadilly had
NOP carry out a dipstick survey to give them
an idea of how many adults (over 15) were
listening to their station in Greater Manchester.
The results suggest 1.2M, and whether this is
accurate or over -optimistic should emerge from
the full diary survey which is already being
planned. Certainly, local radio advertising
seems to work in Manchester. One local shoe
shop bought 21 short spots over a weekend for
a half-price shoe sale. At 9 o'clock on Monday
morning there were 500 people queueing
outside.
One national newspaper, that shall be nameless, is certainly none too keen on Piccadilly.
After the station gave away track suits with
Piccadilly Radio lapels to the Lancashire
cricket team, the paper ran a picture showing
them training in smart outfits rather than in
the usual sloppy sweaters. The same paper
made sure that the Piccadilly Radio logo badges
had been dutifully and carefully airbrushed out
to avoid publicity for the radio station. Somehow I doubt that silly incidents like that will
detract from the long-term success of Britain's
commercial radio stations. But whether in the
long-term the economic climate, the cripplingly
high IBA transmitter rentals, and the large
number of fresh stations due to open over the
next few years will enable the broadcasters to
make a profit, is quite another matter. Only
time will tell that particular story.
for strings and piano, and the Schoeps for a
predictably flat sound that can be `bent' to
whim with equalizers.
The technical performance of all of the
microphones matched their irdividual reputations on the whole-the Neumann U87 and
the Schoeps microphones both had marginally
lower noise than the AKG C414 but there was
little in it. The Schoeps microphones at -58
dBV for 74 dBV gave 4 dB more output (1 kHz
octave filtered pink noise) than the Neumann
U87 at -62 dBV which in turn gave a further
4 dB more than the AKG C414, at -66 dBV.
the tolerances were well within the manufacturer's
specification. After more than twice the usual
time needed for the job, for cutting two parallel
grooves is an exacting task, it was sent upstairs
to the house producer. After about half the
time taken normally, he rang down complaining
that there was some appalling woman on the
disc who didn't sound at all like a superstar.
Up went the engineer, put on the disc and, as
a toss of a coin might have it, out came the
superstar.
Exit engineer, leaving house
producer in some confusion. The next phone
call took longer, but said the same; and there
the joke ended, because the chances against
were 7:1 anyway and couldn't be stretched that
much farther.
When choosing a microphone to buy, the
more modest fixed polar diagram microphones
should not be forgotten (such as Neumann
KM84, AKG C452 or Calrec CM1050) which
start at a fraction of the price of these three
variable polar mics. When we carried out
these comparison tests, a Calrec CM1050 stick
cardioid capacitor mic was included on one
occasion-and did very well against its more
expensive colleagues, although it obviously
lacks the flexibility of variable polar pattern.
® In the most calm and dignified voice at
0.05 am on August
11 last year, Radio 3 vhf:
'This is the Open University and that was the
signature tune at the wrong speed'.
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amplifiers.
Frequency response 10.1 dB 20-20k Hz; power response ±1 dB
5-20k Hz; power output 75W RMS per channel into 8 ohms 20-20k Hz
at rated distortion, typically 100W RMS per channel at 8 ohms, 140W
per channel at 4 ohms; IM distortion less than 0.05% 0.01W to 75W,
harmonic less than 0.05°/e 0.01 W to 75W 20-20k Hz.
NETT PROFESSIONAL PRICE ON APPLICATION
207 at very competitive prices
SOUNDCRAFT 12/4
Just arrived -12/4 Recording Console which is built into a teak case,
incorporating 12 input and 4 output
channels, output limiters, and full
monitoring facilities. All input and
output connectors are Switchcraft
(XLR equiv.) except line input
which are k" jack. 200 ohm mic.
inputs are balanced. 4 band E.Q.;
f/b send; echo send; pfl; channel
switch; pan pots and faders.
NETT PROFESSIONAL PRICE
£875
VAT
+
ALL PROFESSIONAL AUDIO EQUIPMENT AT
RE WAudio Contracts, 148 Charing
VIDIO, INDUSTRIAL AND STUDIOS AT
HEW Video Cootracts, 1012 Hìh St,
REW Audio Contracts are able to offer the following microphones at professional prices (subject to stock) to bona -fide
pro users.
AKG
AKG
SHURE
CALREC
BEYER
D190
D707
D900
D1200
D2000
515SA
588SA
CM652
CM655
M160
M500
M260
MI01
DI60
D109
D12
D90
D200
D202
D202E1
D224E
C451
545
565
548
SM57
SM58
RESLO
S80
CABARET
S91
Available in
DIN or CANNON (XLR) connectors.
ALL PRICES ON APPLICATION
*VERY SPECIAL PRICE Full range of mic stands and
WHILE STOCKS LAST accessories by KMAL.
*NOTE REW Audio Contracts and REW Video Contracts are registered
trade names and are part of The REW Group of Companies.
CroSs Road, london WC2.IeI:01240 3883
Colliers Wood, LooiIoo SWlOiel:01- 540 900415 telex 000104
73
16/2 PORTABLE SOUND MIXER
by
-TURNER
-
Turner Electronic Industries Ltd.,
x
The TPS Series mixer offers all of the
facilities of our 24 channel modular
mixer ... in a non -modular version.
x
From 12 to 24 channels.
Custom variations catered for.
175
Uxbridge Road, London W7 3TH
-
Tel:
01-567 8472
TEAC 4-CHANNEL
INDUSTRIAL
RECORDER
The complete mobile
recording studio
4 totally independent
channels.
Sel sync on all channels.
Mixing facilities 63dB
signal to noise ratio.
Wide flat band width.
BACKED BY
ITA SERVICE SOLE SUPPLIER
SEMI -PRO "S" VERSION NOW AVAILABLE IN
240V
Industrial Tape Applications
5 Pratt Street, London NVOl1 OAE.TeL.01-485 6162 Telex: 21879
74
STUDIO SOUND, JANUARY
1975
improved
radio microphone
systems by
audio limited
AD
007
PORTABLE MIXER
The Mini Mixer with the professional qualities and
the professional performance.
Where it is advantageous to use radio microphones you can
rely on Audio Ltd systems. These are basically in two forms
-one where the microphone is worn and fed to a tiny
transmitter secreted about the person of the user, the other
where the transmitter is contained within the stem of a
conventionally styled hand-held microphone. Audio Ltd
radio microphones are widely used in theatres, TV and film
studios or wherever it is required to use microphones free
from the encumbrance of connecting cables and maintain
quality.
Battery or external power supply operable.
Inputs 4 Outputs all balanced into XLR
connectors.
8
2
Compressors with stereo link.
Peak Programme Meters switchable to all
channels and groups.
2
Auxiliary send and returns.
Modular construction
serviceability.
Inputs extendable to
Extension Unit.
is
18
used to
promote
via the Ten Input
Other facilities include insertion points in each
channel and group, a line up oscillator and cue
facility. The Extender Unit can also incorporate
Talkback and Monitoring at the exclusion of input
modules.
Customers so far supplied have been full of praise
for the mixer. They include people in broadcasting
studios and the live entertainment field.
Avtc
Developments
Hall Lane
Walsall Wood
Staffs WS9 9AU
Tel. Brownhills
5351
Developed out of our original Audio Ltd Radio Microphone System, we offer for
prompt delivery an improved RMS 7 system in which the newest electret capacitor
microphone is used. By slightly enlarging the receiver, we have incorporated a block
aerial filter to greatly reduce cross modulation interference and facilitate multi -channel
operation. The receiver has battery, signal level and tuning meters, also plug-in whip
aerial and output plug and lead. The transmitter is easily concealed in the pocket or
about the user, and the microphone supplied is smaller than the plug used to connect it.
We shall be pleased to forward full technical information on request.
Complete systems as above from £240 -I- V.A.T. Others available from
£176 -{- V.A.T. Literature and other information on request.
UHF
OR
HIGH
POWER
VERSIONS
FOR OVERSEAS
USE
Audio Ltd Radio Microphone Systems as supplied to users in the U.K. conform precisely
to Post Office regulations. More powerful systems and UHF systems can be supplied for
overseas in compliance with locally stipulated operating conditions. Transmitters
operating up to 500 MHz and with outputs up to 500 mW at 175 MHz can be supplied.
AUDIO LIMITED
WENDELL ROAD
LONDON WI2 9RT
26
Telephone 01-743 1518
75
*Experienced recording engineer at present
working on studio construction project in
Nashville, seeks position in or near London
upon return from U.S.A. Enquiries please to
Box No. 689.
Classified Advertisements
Advertisements for this section must be pre -paid. The rate is 8p per word, minimum 80p. Box Nos. 20p
extra. Semi -display rates on application. Copy and remittance for advertisements in FEBRUARY
1915
issue must reach these offices by 18th DECEMBER 1914 addressed to: The Advertisement
Manager,
Studio Sound, Link House, Dingwall Avenue, Croydon CR9 2TA.
NOTE: Advertisement copy must be clearly printed in block capitals or typewritten.
Replies to Box Nos. should be addressedtothe Advertisement Manager, Studio Sound, Link House, Dingwall
Avenue, Croydon CR9 2TA, and the Box No. quoted on the outside of the envelope. The district after Box
No. indicates its locality.
STUDIO FACILITIES
SITUATIONS WANTED
*County recording service stereo and mono
masters and lacquer discs from your tapes.
Telephone Bracknell 4935. London Road,
Binfield, Bracknell, Berks.
*For hire. Revox A77's, Quad amps, A.K.G.
BX20 echo unit, mics stands. Short and long
term rates. Phone Ian, 01-586 0064.
*Musician (23), experienced in record production, seeks position as tape operator/assistant
engineer. Tel. 0223-44125 (evenings).
[t [t [t [t [t [t [t [t [1 [t [t [1 [t [t
(Yarmouth Recording Studios)
Leaflet available
112 Beach Rd., Scratby, Gt. Yarmouth
Tel. Gt. Yarmouth 730136. Member A.P.R.S.
recording and
transcription service
Vinyl pressings
mjb
Assistantgig
Engineer
and production Master tapes. LyrecOrtofon lathe. Specialist audio processors Dolby
"A"/"B"; ADR Limiters, Compressors, Expanders,
Dynamic Equalisers and De -Essers, for getting the best
results possible.
ST. MICHAEL'S, SHINFIELD ROAD,
SHINFIELD GREEN, READING, BERKS.
Reading (0734) 84487
Member A.P.R.S.
*Sound News Productions. Britain's oldes
full-time Tape/Disc/Cassette transfer service
Direct transfers, pressings for private and for
the trade. Fund-raising advisory service for
societies, choirs, bands. 18 Blenheim Road,
London W4.
Tel. 995 1149.
y
RECORDS MADE TO ORDER
DEMO DISCS
MASTERS FOR
RECORD COMPANIES
VINYLITE
PRESSINGS
Single discs, 1-20, Mono or Stereo, delivery 4 days
from your tapes. Quantity runs 25 to 1,000 records
PRESSED IN VINYLITE IN OUR OWN PLANT.
Delivery 3-4 weeks, Sleeves/Labels. Finest quality
NEUMANN STEREO/Mono Lathes. We cut for
many Studios UK/OVERSEAS. SAE list.
V
h
DEROY RECORDS
PO Box 3, Hawk Street, Carnforth, Lancs.
Tel. 2273
*lin. pressings manufactured in our own
pressing plant-speedy delivery. Yarmouth
Recording Studios, Scratby, Great Yarmouth.
Tel. Great Yarmouth 730136.
*Tape and Cassette Recorder Repairs by
Specialists. The Tape Recorder Centre, 82
High Holborn, London, W.C.1.
S.G.S. RECORDING
STUDIO
DEMOS AND MASTER PRESSINGS
MULTITRACKING FACILITIES 01-778 0450
Complete studio service. Mobile studio service engineers. Music publishing.
Independent production
Group P.A. and amps serviced and sold. Disco
equipment installed.
131A ANERLEY
Studio 01-778-0450
76
ROAD, LONDON
S.E.20
Messages 01-688 0728
STUDIO SOUND, JANUARY 1975
The Tape Recorder and
Hi-Fi Specialists wish to purchase good quality
Tape and Hi-Fi equipment for cash. 400
Edgware Road, W.2. Phone PAD 5521.
*All Nagra equipment urgently required for
cash. J. J. Francis (W.G.) Ltd., Manwood
House, Matching Green, Harlow, Essex1CM17
ORS. Tel. Matching 476.
*8 in 2 out or 10 in 2 out or 16 in 2 outjmixer,
suitable for mixing 16mm mag. film tracks.
Please state make, details and price. Lenra
Associates, P.O. Box 10599, Honolulu, Hawaii
96816, U.S.A.
*Ferrograph 4, 5 or 6 recorder wanted for
spares. Box 691. London.
SITUATIONS VACANT
ANGLIA PRESSING COMPANY
Specialists in small orders of 7" and 12" vinyl pressings,
manufactured in our own pressing plant.
SPEEDY DELIVERY
COMPETITIVE PRICES
WANTED
*Lee Electronics.
k
T.V.AudîoSystems
Pye TVT, part of the Pye of Cambridge group, specialises
in outside broadcast systems and services.
We would like to hear from young engineers (aged 20-30),
with audio design and systems experience, interested in
career with our expanding international company.
You should have served a recognised apprenticeship, with
HNC/HND or Full Technicological Certificate.
Your job title would be Assistant Engineer, and you would
join our Audio Systems Department.
You would help design equipment and construct, develop
and test equipment and circuits. You will also produce
circuits, parts lists and technical information for handbooks,
and assist in procuring components for constructing
a
112
01
II
prototypes.
We offer a good starting salary, with considerable fringe
benefits. Plus a career in a leading company in the TV
systems field.
Please write, with details of qualifications and career so
far, to:
David Barnicoat, Personnel Officer
PyeTVT
Limited
[ [ [ [ [ [ [ [ [[ [ [ [ [
Box 41 Coldhams Lane
Cambrid g e CB1 3JU
P O
VVV
BBC TV
Alice
FILM DEPARTMENT
IS
REQUIRES
ASSISTANT FILM RECORDISTS
To undertake the operation of recording and reproduction equipment in sound transfer
and dubbing areas situated in various television premises.
Candidates must have practical knowledge and experience of film sound transfer and/or
dubbing recording methods and techniques, coupled with an understanding of the use
of sound and film production.
EXPANDING
And because of re -organisation in our
factories, we no longer have room to store
the following stock-SO we are having a
clearance sale:
Salary: £2,397 p.a. rising by annual increments of £111 to £2,952 p.a.
Candidates who do not meet the full requirements of the advertisement may be considered for appointment as Trainee Assistant Film Recordists at a salary of £2,127 p.a.
with promotion to Assistant Film Recordist upon satisfactory completion of a one year
training period. This would apply to applicants in the age group 18 to 28 with G.C.E. 'O'
Level standard of education who have some knowledge of basic electronic theory and
are able to show evidence of a practical interest in recording. A course is scheduled to
start early in 1975.
Based at Ealing or Shepherds Bush.
Write or telephone immediately for application form (enclosing addressed foolscap
envelope) to Appointments Department, BBC, London, W1A 1AA, quoting reference
74.G.1138SS, telephone 01-580 4468, ext. 4619.
MIXERS:
ALICEAD52, used (for location mastering)
£80
ALICE SM 10/2 bristling with extras, EMT
£850
faders, power amplifiers
ALICE TM 22/16 22 channel 16 track console, new, but not fully completed.
All modules, cards, etc, in jackfield and
enough parts to build another mixer.
£6,500 or offer
TAPE RECORDERS:
£40
REVOX G36
2 off REVOX HS77 new boxed £300 each
AMPEX 351 stereo deck with one amplifier
AUDIO TEST ENGINEERS
wide range of public
address, communications and broadcast
studio equipment. To satisfy the increasing
demand for our products we require engineers preferably with previous audio test/
service experience and a good practical
knowledge of transistor circuit techniques.
Applicants will be expected to carry out
systems and unit testing of custom-built
equipment, supervise junior staff, and work
with the minimum of supervision.
Vacancies also exist for junior engineers
having ONC or equivalent qualifications
who have a keen interest in audio equipment.
The posts offered will be centred at a new
factory now nearing completion at Saffron
Walden, Essex.
Audix manufacture
a
Applications should be made in writing to:
E2LJdÏX
STAN STE D,
Essex.
*Electronics engineer required for Central
London recording studio. Experience in audio
electronic work essential. Must be keen and
prepared to work long hours. Box No. 690.
*Sound effects library requires assistant
librarian with knowledge of tape to deal with
Film and TV customers. Pleasant atmosphere,
ACTT rates.
Contact Peter Musgrave,
Magnetic Effects Ltd., 23 Redan Place, W2
4SA. Tel. 01-727 9801.
FOR SALE -TRADE
(faulty)
TEAC/SCHAFFER
machine. New
£175
stereo
mastering
£825
LOUDSPEAKERS:
off ALTEC 4178H 12" drivers in PA
£120 the pair
boxes.
£35
JBL 2150 15" full range driver
2 off TANNOY 15" monitor gold in home£120 the pair
made cabinets
2
PEAK PROGRAM METERS TO BS4297
also 200KHz version for high speed copying:
Drive circuit, 35 x 80mm, for ma L.H. zero meters to
BBC ED 1477. Gold 8-way edge con supplied.
4off
10 off
50 off
£9.00
£8.50
Complete kit
£10.00
£9.50
Built and aligned
£14.00 £1330 £12.60 £11.90
I
ERNEST TURNER PPM meters. Below scalings stocked
Type 642, 71 x 56mm £10.90: 643, 102 x 79mm £12.90
TWIN MOVEMENT, scale 86 x 54mm £31.00.
FREQUENCY
SHtiFTER
FOR`:
HOWL
REDUCTION
PUBLIC ADDRESS
:
SOUND REINFORCEMENT
In any public address system where the microphones and
loudspeakers are in the same vicinity acoustic feedback
(howl -round) occurs if the amplification exceeds a critical
value. By shifting the audio spectrum fed to the speakers
by a few Hertz the tendency to howling at room resonance
frequencies is destroyed and an increase in gain of 6-8dB
is possible before the onset of feedback.
SHIFTERS IN BOXES with overload LED, shift/bypass
switch, BS4491 mains connector and housed in strong
diecast boxes finished in attractive durable blue acrylic.
Jack or XLR audio connectors.
Type
A
B
C
Input impedance 200Kohm 200Kohm IOKohm Balanced
Output impedance 2Kohm 20or600ohm20or600ohmBAL
PRICE
£58
£68
£84
SHIFTER CIRCUIT BOARDS FOR WW July 1973 article
Complete kit and board £21
Including p.s.u. and
£28
mains transformer
Board built and aligned
DESIGNER APPROVED
SURREY ELECTRONICS
The Forge, Lucks Green, Cranleigh, Surrey GU67BG
(STD 04866) 5997
CASH WITH ORDER less 5% U.K. post free, add VAT
MICROPHONES:
£35
£50
£25
£120
£10
AKG
AKG
AKG
AKG
C451E
D900E with fittings
C28c head only
C414 new, boxed
BEYER M64 SH new
MISCELLANEOUS:
Transportable carrying cases for AM, SM
Various
and AD62 mixers
£30
HH TPA 50 power amplifier
£40 each
2 off ALICE BD6 limiters, used
COMPONENTS:
200 off 100K Lin/lin Piher
faders
£50 the lot
£70 the lot
off 100K lin, ditto
off 10K and 5K mixed Piher faders
£5 the lot
3p each
1700 off Knobs for the above
£15
20 off TMC push buttons
68 off ANDERS KM 32 100 A meters
£2 each
7 off ANDERS KM 106 assort. £3 each
£3 each
4 off ANDERS KM 106 1 A
£4 each
8 off ANDERS R55 1 A
2 off LINSTEAD multivoltmeters
600
40
£30 each
77
FOR
SALE-TRADE
RAC MIXERS
Custom-built mixers for groups, P.A.,
hospital broadcasting, recording, discos, etc.
RAC plug-in audio modules for building
your own mixers.
Sony, Akai, TEAC, Tandberg, Marantz, Lux,
Nikko, Dual, Quad and Armstrong dealers.
Shure, Calrec, AKG mikes and stands, etc.
APRS Manufacturing members.
FOR
(Continued)
*Nagra III and IV and SN models available.
Immediate delivery. Write or phone J. J.
Francis (Wood Green) Ltd., Manwood House,
Matching Green, Harlow, Essex. Tel. Matching
476.
*Amcron D60 amplifiers, as new, £75 each or
£140 the pair, inc. VAT. Phone: Audio Installations, Basingstoke (0256) 3651.
*A new dB tamer from Cathedral
...
Tel. 0788-810877 (Rugby)
Call, write or phone us
Compressor/Limiter module CLA 1, £15.50 post
and VAT paid. Low distortion oscillator
module OSC/2 £15.50 post and VAT paid.
Quantity discounts available. S.A.E. details
Cathedral Sound, Fourways, Morris Lane,
Halsall, Lancs L39 8SX.
*Ten different colours of 14/.0076 x 2 braided
mit cable in stock. Phone 01-586 0064.
*Revox A77 sold, serviced and modified,
accessories supplied. Full range of modifications that only we carry out. Ring 01-586 0064
for details.
RUGBY AUTOMATION CONSULTANTS
19
Freemantle Road, Bilton, Rugby,
Warwickshire CV22 7HZ
SALE-PRIVATE
*8 channel mixer,
8
12 channel monitor mixer,
Chadacre compressor modules. Offers tel.
01-359 0970.
*Journals-sets-B.K.S.T.S.
1970-73; Tape
Recorder 1964-69; Studio Sound 1970-72. Lot
£9; offers. Phone Watford 26285.
*Large attractive free-standing mixer, 8 in 8
out, electronics in need of rebuilding. Also
Brenell MK6 replay deck (15 ips) with pre amps, reverberation unit, jackfield, large loudspeaker cabinet (contains E.M.I. 19 x 14),
AP75 record player, four packs of Rockwool
sound insulation, all at rock -bottom price for
immediate clearance. Tel. 01-437 8470.
*Vortexion 100w slave amp (as currently
advertised), as new. A bargain for £65. Tel.
01-467 0382.
*Audio Developments mixer, 16 into 4 with 3
limiter compressors, £3,000. Nagra 4D mono
NAB, Beyer phones, £550. Richardson, Fowl mere House, Nr. Royston, Herts. Tel. Fowl mere (076-382) 453.
KEEP IN TOUCH WITH STUDIO SOUND
Place
a
regular order with your Newsagent or take advantage of
a
2Sp
POST FREE Annual Subscription.
INDEX TO ADVERTISERS
Acoustical Manufacturing Co. Ltd.
.. 51
Action Video Ltd.
..
.. 65
AKG
..
..
.. 9, 43
Alice (Stancoil) Ltd.
15, 77
Allen & Heath
..
.. 59
Allotrope Ltd.
..
..
..
.. 63
Ampex (Audio & Video tape rec. equip.) 12, 13
A.P.R.S.
..
..
56, 71
Audio Design Recording
.. 26
Audio Developments
.. 75
Audio Ltd. ..
.. 75
Audix
.. 77
AV Distributors Ltd.
6
Exposure Hi Fi
61
Feldon Audio
Franz Vertriebsgesellschaft
Future Film Developments Ltd.
53
Grampian Reproducers Ltd.
18
Hampstead Hi Fi
H. H. Electronics
14
Klark Teknik Inc.
67
Baileys
..
Bauch, F. W. O., Ltd.
BBC
Beyer Dynamics ..
Bias Electronics Ltd.
Brenell
Lexicon
Lockwood
11
Cadac (London) Ltd.
Cetec Inc. ..
Celestian
Condor Electronics
18
17
77
10
20
15
2
41
51
20
Industrial Tape Applications
..
Macinnes Labs Ltd.
Magnegraph
Magnetic Tapes Ltd
Magritte
Miniflux
Mustang Communications
Naim Audio
Neve, Rupert, & Co. Ltd.
22
50
6
5, 47, 61, 74, 79
64
21
61
10
59
26
20
61
33
Philips
Pye TVT Ltd.
23
Quad Eight Electronics
16
76
Revox
R.E.W. Audio Visual Ltd.
Rugby Automation Consultants
Sansui Audio
Scenic Sounds
Sescom Inc.
Shure Electronics
S.N.S.
Soundcraft ..
Sound Maintenance
Sulamoss
Surrey Electronics
Tannoy
Taylor Hutchinson Ltd.
Trad .
Trident Audio Developments Ltd.
Turner Electronic Industries Ltd.
Turner, Ernest
Tweed Audio
.
80.
73
78
..
..
..
..
..
..
..
57
8
8
7
18
27
18
24, 25
.. 77
..
..
..
..
..
..
..
8
4
59
19
74
26
47
Published by the Proprietors, Link House Publications Limited, 10-12 South Crescent, Store Street, London
WC1E 7BG and Printed by Arthurs Press Limited, Woodchester,
Stroud, Glos. GL5 5PB.
REVOX A77
SERIES
Available in a wide
variety of configurations,
inc. 2 track, full track,
track. Choice of tape
speed.
Backed by ITA Service
IMMEDIATE DELIVERYALL MODELS
(ALSO AVAILABLE FOR HIRE)
THE NEW
REVOXA-700
SERIES
tape speed configurations
Full deck logic
Four inputs
Crystal servo control
Tape footage counter
Servo tape tension
3
Write for full information
IMMEDIATE DELIVERYALL MODELS
Scotch
207
LOWEST UK PRICES
(ALSO AVAILABLE FOR HIRE)
NOTE NEW ADDRESS
I'74
Industrial Tape Applications
5 Pratt Stret,,London NW1 OAE.Tel: 01-485 6162 Telex: 21879
,
;<;
How to
keep the
musical
excellence
you've
already
paid for:
Your tape system
The tape equipment of your system
is your musical memory bank. It is
the one area where only the best
makes sense. Choose carefully,
select a recording instrument that
neither adds nor detracts from the
sound you put into it. Few
machines really meet this
requirement. The Revox A77 does and by a safe margin.
Your tape recorder and your money
A truly professional quality tape
unit is your wisest audio
investment. It will last for years
and years.
Witness the number of Revox
machines built more than 20 years
ago that are still in service It's
hardly surprising then, that Revox
recorders command very high
prices second or third hand - if you
can find them available
Revox owners seldom change other than to a later model Revox.
It's also interesting to note that
our warranty records show that on
average our users have bought 2 or 3
eher makes before choosing
Revox. Then we read the lament "I
only wish I'd bought a Revox
sooner."
!
!
When you play it later, will it still sound the
same?
At first sight this could seem an
unnecessary question. It's not
though. In the course of time a high.
fidelity enthusiast upgrades one or
more units in his system.
With time, rising affluence plus
advancing technical innovation in
all aspects of audio, will bring
better reproduction within the
scope of all.
The recordings that you make
now could, therefore, sound even
better in the future - when, as
finances permit, you add a better
amplifier or loudspeaker to your
equipment.
Conversely, a poor recording
made now will sound really inferior
when exposed to more exacting
playback.
With the Revox A77 you will
retain the excellence of every
recording to enjoy now - and
perhaps appreciate even more in
the future.
So visit your nearest Revox
Dealer for full information and a.
demonstration.
Record it on a Revox
R EVOX
© Admark International
The illustration contains optional extras.
All
in
Revox C. E. Hammond & Co Ltd; Lamb House Church Street London W4 2PB.
Revox Corporation, 155 Michael Drive Syosset N.Y. 11791 U.S.A.
Revox Corporation 3637 Cahuenga Boulevard West, Hollywood California 90068.
Revox International: Regensdorf 8105 ZH, Althardstrasse 146 Switzerland.
BNE
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