IECHNIQUES FOR AUDIOIAPE fIIASIERITIG

In the recording of original tapemasters for phonograph records andtape duplicating, tlere are sometechniques that are better thanothers for producing a quality prod-uct. The methods to be descritredhave been developed over a numberof years in the professional record-ing business.

MosteringBetter high-frequency response,

ease of editing. and wider dynamicrange are obtained when the masterrecording is rnade fulI track at atape sp€ed of 15 ips. Master tapesshould be made only uith first-lineprofessional mastering tape. Thismay sound extravagant at first, sinc€almost any tape will acc€pt a signal,but experience shows the advisa-bility of using such tape. Absoluteperfection from both a technical andartistic point of view is difficult toattain. Conscientious artists andartist and repertory (A & R) men,when listening to playback monitorspeakers-usually under high-levelconditions-can often sense eventhe most minute tape-motion flawsand other disturbances possibly noteven connected wirh the recordingequipment. Thus the engi.neer mustdo everything possible to insurehighest recorded quality, and ttreuse of unspliced professional-gradernastering tape js essential ro main-taining that quality.

To provide a "protection tape,"a second tape recorder may bebridged across the program buss.This machine runs at 7.5 ips andprovides a full-track "copy." Thissecond tape is recorded at the sametime as the rnaster and can bethought of, therefore, not as a copyat all, but rather as a slow-speed,low-noise original. This method hasproved to be a valuable time saverin case the client wants such a

66

by John D, Hatmet, Presidenl andChief Engineer, Capiial Cify SoundRecording Co., Columbus, Ohie-Somepoiniers lo help lhe sound recordingengineer produce a befler producf.

"copy" of the master material foraudition purposes.

SplicingWhen a splice must be made,

perhaps the most important singlefactor is maintainilg tJle two tapeends parallel. The tape splicershould be one having superb tapeholding and aligning qualities, evenif it is not as fast to use as othersor requires some handling of thetape for trimming. However, thebest rule to apply when makirgoriginal or second- or third-genera-tion recordings is to avoid splicesif at all possible. Few things shortof a tape break will ruin a goodrecording more quickly. Even care-fully trimmed, well-made splicrscan cause a momentary "bump" or"flutter" when going over stabilizerflywheel drums or across heads andthereby perhaps ruin an otherwise"perfect" performance.

Equipment ConsiderotionsEach recording session may (and

often does) require a differentequipment arrangement; however,

Fig. l. A yersotile orftngehent lo? odd.iltg ccho elfccts to the qudio progrEn.

the following general approach ce:-usually be applied:(A) Musical instruments and roc:.

artists should be seprrrtecwhenever possible. This mavrequire the use of portablesound - absorbing foldin5screens to increase the appar-ent distanca of separation.

(B) A different microphone shouldbe used for each group or in-dividual so separated.

The purpose behind this separa-tion is to gain more flexible andindividual mixer control over thevarious portions of the entire re-cording group. This allows, forexample, the A & R man to call for(and the engineer to supply) in-creased volume level for tJte vocal-ist without a corresponding increasein the level for the orchestra.

Micophone EqualizalionThe use of individual microphone

equalizer controls is well establishedin many of the major recordingcompanies because it is an ex-tremely Yersatile tool. This maycause some raised eyebrows amongreaders accustomed to working \ryithbroadcast transmission systems hav-ing essentially flat frequency re-sponse. Broadcast systems are de-signed, by and large, to transmit,unaltered, signals they receive frommicrophones, lines, and reproducers.On the other hand, the purposeof a recording studio is to recorda performance and to alter, if nec-essary, the characteristics of thatperformance to produce a morepleasing recorded sound. In addi-tion to adjusting the relative levels,this might mean increasing thehigh-frequency response of onemicrophone to obtain a crystal-sharp piano "ring," reducing thelow-frequency response of the voicetrack to retain clean, understand-able dialogue, or introducing vari-

B ROA D CAST EN GI NEERI NG

Q,n/r4 nuBROADCAST

TRANSMITTERSEXCEED fCC sPECS.

d frnoliltir

250W500wtKw5KWtoKw50KW

Alrl & FM IRANS {IIIERS AI REAIISflC PRICESClrcl. lt€n rt or Lch Dot C.rd

A <ornplele towerereclion servirethot hos thesesperiol odvontoges:

I DIPINDABIIIIY/ RTI.IABIUTYy' (omPtflt

TNGINTIRING

e/ coAsT T0 c0a5lsERVtft

y' RTPRTSTI{TATIVTSw0RtD-wtDt

8e rur.lo obhii prk. quolo.liont ond engine?ring os5kr.on(e lor your romplete l0werneeds from Ameri(o! foremottower uaalion iaryke.

CCA ELECTRONICS CORPORATION716 tERsEy AvE., ctoucEsTER ctTy YouR

cAMDE|r couNry, flEw JERsEy lNourRY

TELEPHoNE: (609) 4561716 lNvlTED

ccA - AM . sooo D

Th. CCA AM-5000D sRw' AMb.oadcast transmitter inco.porates fea-tures that ar€ standard in all CCA AMtransmitters. These includ.:

Silicon .ectitcrs with minimum of200t/. salcte factor: 300r .eserv.in air cooli;c; ninimum rlibe cosrsilow distortion hish l.vel plare hodu.tation, automatic ov.rload reclcl'np:hinimum f,oor space; full acccssrbrlrtywith hinecd mcter panels.

?onu$ 2,995.OO$ 4,195.OO$ l,acs.oo$12,900.00$l6,600.00$83,OOO.OO

Fig.2. Usudl nelhod hos di5odvqnfog6.ous degrees of echo into sorne ofthe microphone channels. All thisresults in a coloration of the orig-inal sound to produce a product inaccordance with the wishes and de-sires of the producers, the A & Rmen, and the pe.rformers tiemselves.Echo Devises

Most recordings made todayhave some amount of artificial re-verberation added. Artists and A &R rnen demand echo effects, andthe engineer must supply them.

One method of producing echoeffects that has been found to workwell is the following: The recordingconsole equipment is modified sothat echo send signals are derivedfrom the channel selector keysthrough a transforme,r bridghg net-work (Fig. 1). The output of theecho receive amplifier is broughtto a mixer control on the console.This arrangement allows the record-ing engineer to add any amount ofecho at will. In general, reverbera-tion devices af,e so connected thatthe input of the device is isolatedfrom its own output to preventfeedback.

A one-shot "slap echo" can beobtained by the arrangement in Fig.1 if the echo device is a tape ma-chine (usually running at the 7/zips speed) set up for tape monitor-ing. This effect is differentiatedfrom the norrnal tape rgverberationin that it is a one-time echo anddoes not decay as the echo pro-duced by a re-entrant system does.

The conventional method of in-troducing reverberation (Fig. 2) hassome inherent drawbacks. In thisarrangement. the program amplifierand the echo section form a closedloop. Instability due to feedbackappears before a substantial echolevel can be obtained. A furtherdisadvantage is that reverberationis applied to all signals after mix-ing, and selective echoing of ind!

BROADCASI ENGINEIRING

DID YOU KNOWYou can have your old cartridges recon-

ditioned by expertsno charge for minor partsALL cartridges PRETESTED underactual broadcast conditionsno minimumno service charge for small ordetsreturn shipment in 48 hoursfactory trained personnelnew cartridge warranty

You can have any size Fidelipac tapecartridge shipped immediately fromstock

You can have all cartridge parts for doit yourself cartridge maintenance.

JoA incorporates all ol lhese as a rarl oftlreir seryice to lhe brordcast.r.phohe or writ€:

Clrcla hcm rO on Lch Doro Co.d Clrclc lt m 2l or t Gh D.ta C.rd

vidual sources is thus impossible.

PickupsA somewhat unique, though by

no means original, method of pick-ing up electricatly-operated musicalinstruments is shown in Fig. 3.Instruments in this class includeelectric guitars, bass guitars (oftenaccompanied by huge amplifier-speaker systems), electric organs,electric pianos, and electric basspianos. ln the arrangement of Fig.3, a connection is bridged across

the voice coil of the instrumentspeaker. This type of pickup hasbeen used frequently with goodsuccess.

Use of this method has generatedsome interesting byproducts, how-ever, not the least of which is ageneral increase in backgroundnoise level. Most of the noiseenergy is power-frequency hum andbuzz; frequently, there may be asmany as four instrument amplifiersoperating at the same time in thestudio, and each contributes noise.

It's certainly not for want of trylng. SinceMarconi introduced the first 47, inch lm-age Orthicon camera, everybody and hisbrother have been trying to catch up. Athousand l\,4arconi 4y2" cametas havegone into service in 38 countries. TheMark lV has literally becorne the world'sstandard television camera. And for goodreason. lt's the car'rera that irproved pic-ture quality 50%. lt was the first camerato make it possible for the cameraman toconcentrate entirely on composition andfocus-and leave all other functions tothe control room. Another first: once youset it up it stays set up. Little wonder thata lot of people have been trying to dupli-cate it. But there's one hitch. While theothers have been trying to build a camera

as good as the Mark lV, Marconi has beenradically improving it. Long-lived siliconrectifiers have replaced selenium units inthe power supply, A shlelded yoke keepsthe camera in focus even if there's mag-netic interference. A solid-state head am-plifier has been added. And the Mark lVis now instantly switchable f rom one worldstandard to another. ln short: by the timesomebody makes a camera as good asthe 1959 model l\.4ark lV, they'll have the1964 model to contend with. And thatgoes for the whole line of Marconi special-tiesr vidicon telecine equipment, switch-ers, color cameras, closed circuit vidiconcameras and accessories. Distributed byAmpex Corp., Redwooo Ciry, Ca'ifornia.Term leasing and financing is available.

Fig. l. A nethod tor in*runelll plclup.

Unusual conditions sometimesarise. In one such instance thatoccurred with an electrically ampli-fied guitar, there was an all-too-familiar ground-loop buzz, but noamount of power - cord, reversingor experimentation with separateground wires seemed to reduce thebuzz. The noise pe.rsisted when theinstrument was held or strappedabout the musician, but it stoppedwhen he laid the instrumentdown. When the engineer accident-ally touched lhe musician whilegrounded, the noise was reduced.Several combinations ol groundwires were then tried without totallysatisfactory results. Finally, in des-peration, the engineer tried havingthe musician stand on a largegrounded sheet of metal. This re-duced the noise enough to permitcontinuing the session.

Another forrn of noise is low-frequency disturbances caused bythe musicians' fingers and hands onguitars or other instrurnents hungabout the neck or otherwise in closeproxirnity to the body. However,these are small technical difficultiesthat once explained and demon-strated to the A & R man canusually be cleared up with tactfulinstructions to tie artists involved.

A further matter to consider isthe relative studio sound levels fromvocalists and instruments. Elec-trically operated and arnplified in-struments usually deliver better-quality sound when run belownormal output, and this definitelyshould be encouraged by engileersand A & R men, since the direct-tap pickup allows the volume levelto be restored by the mixer control.Moreover, lower instrument volumepermits greater flexibility, since thesound issuing from instrumentspeakers in the studio is not solikely to be picked up on adjacentmicrophones.

The subject of piano pickup has

B ROA D CAST ENCI NEERINC

@AM.EXc.Rp 1e64 W i...XM.Fex,,.

NO ONE HAS EQUALLED THIS CAMERA

Ch.l. lt6 25 on Tcch Dotq Cord

S E E..rthemoTV

st advanI ight ing

cedlll

fo\offiLIGHTINGSYSTEMS

and

(o\oGPORTABLE

ELECTRONICDIMMERS

at the

lrAB SH0WBOOTH 231 (Sheroron Pork)

ColorTran quarlz-iodine lighling equipment is in dailyuse for lelevision studio and location lighting throuEh-oul lhe world. Don'i misr lhe dramalic C-olo.Tian erhiii+and demonslrafions al the NAB Show.

Clrcl. llcr 28 on t .h Ootd C.rd

been discussed at length elsewhere.so it will bo considered only briefl1'here. A satisfactory and pleasinglvclean pickup from a vertical grandcan be obtained by using the farnil-iar ribbon-type microphone. \f ithindividual equalization in the pianopickup microphone channel, thecharacter of the pickup can bechanged from bright stage-fiontpickup to a more mellowed back-ground sound.

Experimentation with severa.lpickup positions has shown that twosuch positions give best overallresults in our studio environment.ln one position, the microphone isplaced 2' to 3' in front of the in-strument at a point in line with Cabove high C on the keyboard. Themicrophone faces the soundingboard, and the instrument frontcover is removed. In the other posi-tion, the microphone is placed 2'to 3' directly above the piano at apoint in line with highest C. Thetop lid of the piano is removed,and the microphone faces directlyinto the instrument.

Client Rel<rtionsSome of the toughest jobs for a

recording studio occur when musi-cal talent having no previous record-ing experience is encountered. Thesepeople may test the microphonesby blowing into them, or they mayinsist on playing instruments withvolume levels approaching thethreshold of pain. It is a good ideato try t0 release the studio space tothe client r/z ho]ur in advance ofthe scheduled session to allow timefor the client to become accustornedto the premises and facilities andto p€rmit instrument set-up time.If the engineer is on duty duringthis advance period, he can makethe musical-instrument pickup taps,if any, determine a general micro-phone plac€ment, and give whatadvice may be helpful.

ConclusionThe techniques for making pro-

fessional tape masters depend some-what on the individual circum-stances. It is hoped, however, thatthe general comnents given herewilt be helpful to those who may becalled upon to assume the tech-nical responsibility for making suchrecordings. A

'ROADCASI EN CI N EERI NC