In the days of analog recording the Detroit engineer would clean-up and sort of pre-master the multitrack before the mixdown process began. For a major production, the engineer worked with the multitrack recording of a tune for 6 or so sessions before mixdown could begin. During that time (spanning 18-30 hours), the engineer had to mix monitors, cues and run-offs after each session. The engineer heard the tune when it was only drums, bass and rhythm and all the way through the process of becoming a finished production.

The idea was to get the tape so that it contained only the final sounds of the production. The following type of things were done to the tape:

1. Spot erasure of any noise or unnecessary ambiance in the tracks was done. This would be things like erasing the lead vocal track dung the intro and instrumental break, getting out coughs between the lines, amplifier hum before the guitar solo, etc.

2. Process, ride levels and bounce tracks. Often a Pultec equalizer and/or Teletronics limiting amplifier would be wanted for guitar and bass and maybe for other tracks. To simplify mixing and to allow multiple-use of processing gear, tracks would be processed and bounced to an empty track. When a guitar track might need a significant level change for the lead solo, this would be bounced with the level changes and any processing changes desired.

3. Effects bounces would be done when a delay effect or reverb was wanted on a particular instrument. A track could be made and called "guitar echo" with a tape-looped echo effect recorded on it - to be mixed in with the "dry" guitar later.

Composite tracks would be made. It was not uncommon to have several vocal performances on several tracks and then edit a final vocal track by bouncing. The engineer of the 60's and 70's didn't have the convenience of console automation and a "bizzillion" effects units in the rack, but still had to get the sound.

When console automation came along, 65% of the reason for multitrack pre-mastering vanished. Another 20% has become unnecessary because of the multiple and inexpensive processing devices available today.

The last 15% has not been replaced by modern technology, this being the convenience and assistance to mixing caused by pre-mastering. When a multitrack is pre-mastered, the engineer spends all of his time mixing, rather than "cleaning-up" the sound.

The Motown Heritage Of Pre-Mastering The Multitrack

In a way you could accurately state that Lawrence T. Horn, Motown's Chief Recording Engineer mixed every Motown release between 1964 and 1967. Lawrence did this remarkable feat by implementing a recording "system" for Motown and by ingenious management of a staff of engineers.

His claim to fame came from his system developed for 3 track recording in 1964:

1. Any staff engineer would record a basic session on three tracks. The engineer was strictly forbidden from using any eq, compression or any other type of signal processing.

2. Lawrence Horn would mix together the three tracks into one track. To do this, he would play the multitrack master on a playback machine and record onto track one of the 3 track master recorder. Lawrence would use all of the processing gear to make this mix. He was basically doing a "final" mix of the rhythm track. This procedure made a "B" reel that could further be recorded on.

3. Any Staff engineer would cut the horns onto tracks 2 & 3 of the B reel. Brass instruments would be on one track and woodwinds would be recorded on the other track. Again the engineer wouldn't be allowed any signal processing.

4. Lawrence Horn would take the B reel and mix the horns with signal processing onto track 2 of a new 3 track tape, making a C reel to allow further recording. Track 1 (final rhythm) would be copied to the new C reel at the same time.

5. A more experienced engineer would record the strings onto track 3 of the C reel. This job wouldn't be given to the greenest engineer on staff.

6. Lawrence horn would mix the stings and horns onto track 2 of a new, D reel, using, of course any signal processing he deemed necessary. Track 1 would again be copied to the new D reel at the same time.

7. Any staff engineer would record background vocals onto track 3 of the D reel without any signal processing.

8. A more experienced engineer would bounce the background vocals and add lead vocals, using signal processing to a new E reel on track 3.

The E-Reel had all of the final "mixed" elements and was the final multitrack reel used for mixdown. All staff engineers would be invited to mix the production off of this reel and submit their mixes to the Quality Control Department. Quality Control would pick the best mix. Engineers would "compete" for the mix that was chosen for release.

Since Lawrence Horn did the transferring & mixing to make the multitrack, he actually did most of the mixing on the released version. Since he was good at mixing, he often would be the engineer that won the mixing competition.

Today's Project or Home Studio

Today's home project engineer and even the studio engineer can learn by the original Motown recording system. Like the Motown engineer, there is often one piece of processing equipment that could be used with different settings for different tracks. When the project engineer bounces with digital recording equipment, there are no large noise restraints that cause noise buildup. The Motown engineer had a real noise problem with those 1960 vintage 3 track analog recorders.

Project studios having 2 MDM's (ADATs or DA-88s) have it made, because they can bounce to a new reel of tape and still retain their original tracks on the original reel. The interesting thing is that Digital Audio Workstations are more-or-less setup to do this pre-mastering to the multitrack recording.

Dedicated Digital Audio Workstations such as the Roland VMS 880 have a feature that several performances can be recorded onto one "track." Only one version may be played back at a time, but this version can be an edited version made from all recorded performances. This is one of the key ingredients to pre-mastering the multitrack.

PC based Digital Audio Workstations, such as Cakewalk Pro Audio have "plug ins" available that can be used to "process" tracks with effects. With the track copying features, you can keep a copy of the original,

The mid-1960's engineer had to pre-master correctly. Once new parts were added, one was stuck with the mix used for bouncing the track. The home or project recordist of today can use the same techniques but go back and re-do any mix anytime.

Conclusion:

Engineers of old had to be both smart and good to get the best sounding final mix. New engineers can be as smart but actually don't have to be as good to get good results. Premastering the multitrack allows the engineer to concentrate on getting the best mix without having to "correct": the recording and mix at the same time.