A Short History of the Multitrack Recording Studio
(adapted from Wayne Wadham's Sound Advice: a Musician's Guide to the Recording Studio)
(this book is currently out of print)
There have been four separate stages in the development of music recordings studios, roughly aligned with each decade since the 1950s. Until the late 1940s, music was recorded in two ways, both mono. Many recording sessions were done direct to disc, with one or more lacquer masters cut right in the studio. If the music was for a film soundtrack, it was recorded directly onto a 35mm optical soundtrack negative. Running at 18 inches per second, and with about 55 dB signal to noise ratio (abbreviated S/N, a parameter we'll define later), this method gave better overall sound quality than any disc of the time.
Tape recording, developed by the Germans during the Second World War, was used both in radio broadcasts and for the deciphering of intercepted code messages. The poor sound quality obtained on that early equipment, due largely to inferior tape, soon improved with the introduction of commercial recorders and new tapes by Telefunken in Europe and Ampex in the United States. These machines were mono, full track (one 1/4" wide track), running at 15 ips for music-quality performance. Lower speeds were usually reserved for voice recording. It was discovered early that you could overdub by playing back a previously recorded tape through a mixer, blending that with live mics, and sending the composite signal to a second recorder. In the history of record production, this simple step rivalled the invention of the wheel.
Obviously, the pre-taped music lost a bit of sound quality and gained a bit of noise. Nevertheless, this technique did allow artists to add layers of new music. Such mono-to-mono copy-overdubbing was the standard in pop music production up until 1962. Until that time, pop and rock records were made to sound good on AM radio-in highly compressed mono. Not much attention was paid to true stereo in pop and rock until 1967, when the Beatles brought out Sgt. Pepper's Lonely Hearts Club Band. While stereo was entering its second decade for classical and jazz recording, these genres were played primarily on FM. Rock was usually confined to AM until the early 1970s.
Throughout the 1950s, record companies owned most of the better recording studios, renting un-booked hours to outside users for radio and TV commercial productions. There were very few independent studios of any real quality. For rock, the large, well-designed acoustic space did not matter as much as the engineer's ear for getting excitement into the mix.
Of the staff engineers at major labels, certainly Billy Porter of RCA stands out. His work on Elvis Presley's earliest hits is a marvel, both for its fine technical quality and many innovative techniques. In the jazz field, Rudy van Gelder engineered the Blue Note and Prestige sessions ofJohn Coltrane, Miles Davis, and other artists. The crisp and clean cymbal and horn sounds on these tapes challenge even the compact discs on which they are now being rereleased.
In 1955, hit guitarist Les Paul commissioned Ampex Corporation to build a custom recorder, with eight parallel tracks to be inscribed on special I"-wide tape. He and his wife, Mary Ford, had done many tape-to-tape records, layering six or more guitar and vocal parts, but they were displeased with the build-up of noise and distortion, not to mention the limited control inherent in the mixing process. The first Ampex 8-track was delivered the next year, and Les and Mary proceeded to make a string of Top 10 hits on it. He developed almost all the techniques and tricks that later became standard in multitrack sessions--headphone or cue mixing, sel-sync overdubbing, bouncing tracks, prelaying effects and delays, and special varispeed operations.
The late 1950s brought an acceptance of the 2-track recorder in rock sessions, but mostly as a convenience in producing mono records. Basic tracks could be laid down on one track, some instrumental overdubs (perhaps even horns or strings) on the second track (recorded while these musicians heard a headphone playback of track 1 via the record head, later called sel-sync), then both tracks mixed onto the first track of a second machine along with another live overdub. The vocals might then be added on the remaining track of machine 2 and a mono mix made on to a full-track recorder.
This process saves at least one tape generation on the basic tracks, gives better control over the level of each overdub, and does allow a remix of at least the vocals and completed tracks. The resulting 2-track tape makes pretty anificial stereo, as evidenced by hits as late as the Beatles' "Nowhere Man" in which all voices and the guitar solo are on one channel and everything else is on the other. As George Martin has pointed out most records produced this way were not meant for stereo issue. The two tracks merely allowed better control over elements in the final mono mix. Record companies, in the wake of public demand for stereo, simply released anything they could find, no matter how artificial it sounded, and regardless of how much the artists objected.
Ampex introduced a stock model of its 1/2" 3-track machine in 1960. It offered sel-sync on all tracks and gained its first acceptance with producers of jingles, mainly because a narrator could be added on the third track, rather than on a subsequent pass on 1/4" requiring another generation loss of the music. The 3-track did enable some of the first quasi-natural stereo pop records, however, since the lead vocals could now be mixed into the centre, with the music on left and right channels. On the other hand, some rock engineers really had no idea of how to use the medium. There is even one story of a top engineer who used the third track only for acoustic or electric bass.
My own favourite early multitrack memory is an afternoon in 1964 at A&R studios, then on 47th Street next door to the original Manny's Music Shop. Another engineer burst into the control room where my group was working and declared, "It's here" Our own engineer (now a major producer) took us out to witness the unpacking of A&R's first 4-track Ampex. The entire staff was speechless, circling it as though a spacecraft had landed. Just four years later, the 8-track became the pro format for rock, and independent studios began springing up in every loft or converted office space, rentals rose to an unheard-of $60 per hour.
Until around 1968, it was fairly standard practice to do two completely separate mixes of singles and albums-one for radio play in mono, the other for home playback in stereo. This caused sales and promotional problems when the mono and stereo mixes of a particular tune had a different sound or feel. Since the mix can make or break a record, labels wanted only the "hit" mix-mono-to be played on the air. Meanwhile, FM rock stations, then developing their first legs, insisted on playing stereo whenever available. As a stopgap some stations installed primitive delays and reverbs to simulate stereo. Others actually bootlegged stereo tapes of hits out the back door of certain studios-unauthorized midnight mixes made by underpaid engineers.
CBS came up with a novel solution: Compatible Mixing. This was really nothing more complex than mixing to stereo tape while monitoring the process with both channels mixed to a mono signal. The finished mixes maintained their characteristic sound or punch whether played in mono or stereo. Often, simultaneous full-track and stereo machines ran to give a first-generation mono and stereo product. The process was discontinued in the early 1970s, when the major labels stopped pressing mono albums and singles.
By 1970, 16-track was gaining acceptance for rock production in the United States, though even the Beatles continued to use 8-track through most of Abbey Road and Let It Be in that same year. The Ampex MM-1000 16-track package cost almost $35,000 and required a much more elaborate console than was previously available. Split designs became the standard, the main bank of faders used for mic/line inputs feeding the recorder, the monitor section off to the right used to provide cue mixes and other sub mixes for reverb chambers, and so on. Although Ampex and Scully announced 24-track models to come, there was little rush to buy them because of the noise build-up inherent with so many separate recorded signals.
The real demand for 24 tracks came from clients-artists and producers who wanted the control and versatility, even at the expense of more noise and cost. The Dolby A system provided just enough noise reduction to bring 16 tracks of tape noise back down to the noise level of a good 2-track machine, but the first systems were expensive-almost $2,000 a track! Not many studios could afford it, and not many artists wanted to pay the extra in rentals. By 1970 top studios were charging more than $100 per hour.
Aside from refinements made in existing devices--quieter and more precise parametric equalizers, smoother compressors and better plate reverbs-few new tricks except mechanical flanging were added to the engineer's bag. First made popular on a single named "Itchycoo Park" by the Small Faces, flanging was accomplished by playing two copies of a finished tape back on two machines and mixing their outputs. One copy was started a fraction of a second before the other, and drag was manually applied to the playback machine's feed reel, slowing its speed just enough to bring the two copies into, and then past, exact alignment. The dramatic swishing underwater effect of the resulting comb filter began appearing on every record and really established the commercial demand for a whole range of effects that are now available in various digital units.
As more artists in pursuit of a signing found independent funding to make demos and even master tapes, privately owned studios sprang up everywhere during the late 1960s.
The 1970s brought new formats and devices-both for studios and musicians. The Kepex and other noise gates were invented and used to great effect in albums such as Jeff Beck's Blow By Blow. After Roy Halee had used multiple reverbs to create the cavernous effects on various Simon & Garfunkel hits, such as "The Boxer" EMT finally brought out a true stereo plate reverb around 1970. The first delay lines came out in 1973, including the Cooper Time Cube, with around twenty milliseconds of Acoustic Delay (created via flexible tubing through which the input sound was sent from a small speaker to a microphone at the other end, with a preamp to bring the signal back up to line level).
Expanders, Aural Exciters, and the first generation of digital toys such as Eventide's first digital delays appeared on the scene by 1975. Next to come along EMT's now-famous Model 250 reverb, which (retailing at a mere $28,000) looked like a small red android and was later compared to R2D2. This was the first unit to allow programming of various digital spaces, and also developed enough heat (with hundreds of internal memory chips) to fry an egg on top!
The biggest development of all--console automation--began with the APYAllison system in 1975. This system stored automation data on one or two tracks of the 2" tape. In 1978 Neve introduced its NECAM system, using floppy discs to store the data and identical SMPTE time code on the 2" tape and floppy to synchronize the whole operation. The other hot new device was BTX's system for interlocking sound and video playback. As you might guess, the BTX was developed for use in film scoring and jingle work, where perfect sync is mandatory. The idea of using the system to interlock two multitrack tape machines came later, and with it the birth of 46-track, 69-track, and the other baroque formats used today. To my knowledge, the ultimate is still Arif Mardin's 1984 production of the Italian group Scritti Politti, for which five 24-track machines were locked up during the mix.
Digital recording as a medium for pop and rock really did not happen until the mid-1980s, when compact discs made it possible to get all the added and expensive quality out to the public. However, 3M Corporation did bring out a 32-track digital machine--the legendary DDS-in 1977. With the 4-track mixdown machine and all the interconnects. Only a few rock albums--notably Steely Dan's Gaucho and Ry Cooder's Bop Til You Drop-were recorded on this system because of the extreme cost and complications involved. Studio owners were still reeling with the almost--yearly cost of converting their operations from 4- to 8- to 16- to 24-track, adding $30,000 worth of Dolbys, and buying new consoles one moment and trading them in the next.
Digital, with all its obvious sonic advantages, was financially just out of the question, and as a result, 3M sold only a few dozen of its systems in a five-year period, discontinuing the line in 1982. Sadly, many engineers believe the DDS sounded better than any digital multitrack available today. Meanwhile, classical and jazz recording took to 2-track video-based digital systems like a duck to water. No overdubs--no punching in-limited editing, but what sound quality! The first Sony Analogue-to-Digital converter cost under $2,000 and could store its output on almost any VCR, although 3/4" gave the least dropout and error problems, and the tape cost about $25 an hour-less than 1/4" analogue tape recorded at 15 ips.
If studio owners were dizzy with new equipment in 1980, they certainly had no idea what was in store by 1988. The most important new types have been the computer-monitored mixing consoles such as the Solid State Logic, digital reverbs, and dedicated effects systems (ranging from inexpensive models by Korg and Ibanez up to the Lexicon 224 XL, 480, and later models), synthesizers with MIDI (Musical Instrument Digital Interface), drum machines and sequences, digital multieffects devices (such as the Yamaha SPX-90 with dozens of internal programs), and finally the Apple Macintosh computer, used by musicians to write and arrange music and by studio engineers to control the simultaneous operation of sequencers, samplers, consoles, and tape machines.