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Tips & Techniques:Acusonic Recording Process - Bruce Swedien

>The Acusonic Recording Process<


When Quincy Jones, Michael Jackson and I were recording the Michael Jackson album “Off The Wall”, we wanted to coin a catchword phrase to represent my recording technique with multiple multitrack tape machines. So we came up with the phrase “The Acusonic Recording Process”. To my continued amazement, I am frequently asked to explain.

In fact on several occasions I have been offered impressive sums of money by recording studios, and companies that wanted to purchase “The Acusonic Recording Process”, thinking that it was a “Black Box” that recorded sound could be processed through.

I recollect one awkward circumstance, several years ago, when I got a phone call in the studio, from someone’s secretary, saying that a photographer’s team from a very respected, very important, foreign trade journal, was in an airplane on the way from somewhere overseas, to shoot a cover photo of “The Acusonic Recording Process” machine! I don’t remember exactly what I did, but I do recall mumbling something to the highly confused photographer about the machine being “away for repairs” indefinitely, and we’d have to reschedule the photo shoot! On my last lecture trip to Japan and Europe, I did admit to the press what the real deal with “The Acusonic Recording Process” was!

I had no idea when Quincy, Michael and I came up with the name that there would be so much interest in it.


The year is 1977. Quincy called me one night and said "Want to go to New York and do a musical movie?". I said "Sure!". So off we went to do "The Wiz" for Universal Pictures. While we were working on “The Wiz”, we met this young, 18 year-old kid by the name of Michael Jackson.(Michael played the 'scarecrow' in the 'Wiz', the movie)

It was on the 'Wiz' that I began seriously using two or more
multi-track tape machines together to realize the production values
that Quincy and I were interested in.

It was during the recording of the score for the 'Wiz' that I came up with the basic system of organizing the tracks, the master tapes and the slave tapes that I still use. I call it "Multi-Track Multiplexing". This is the basic concept that spawned the catchword phrase the "ACUSONIC RECORDING PROCESS".

The "ACUSONIC RECORDING PROCESS" is, in reality, merely a name that Quincy and I came up with to describe my recording technique with multi-track recording machines.

The phrase is essentially a combination of the words ‘Accurate’ and ‘Sonic’. I figured the ‘Accurate’ part of it referred to the accuracy of true stereophonic sound imagery. The ‘Sonic’ part of it refered to the fact that it is sound that we are trying to characterize.

More specifically, the name "ACUSONIC RECORDING PROCESS" describes the way that I work with digitial and analogue multi-track tapes machines and SMPTE time-code to generate a virtually unlimited number of recording tracks. Initially I designed the system specifically for the projects that Quincy and I have done together.

I think the most important feature of this technique, and my method of implementing it, is that I am able to use pairs of tracks, in abundance, to record true stereophonic images, and then retain them in discrete pairs until the final mix. This method also allows me(when I use analogue recording in my work) to play the master tape only a few times during the initial stage of the project, and then put it away until the final mix. This feature retains much of the transient response of the analogue master tape, by not diminishing those fragile transients due to repeated playing during overdubbing and sweetening.

I frequently mix recording formats with my system of multiplexing multitrack tape machines. Now, of course, I use digital recording machines, in abundance, alongside my analogue machines. I think that what the basic digital recording medium does, it does dramatically well. Once I have the character of the sound to my liking, I will use a digital recording device to preserve it. As a storage medium, digital recording is unparalleled.

When I am working in the analogue format, I make several of what I call 'Work Tapes' using the original master SMPTE track and regenerating it through a code restorer so that the time-code is always first generation quality. I will then mix the rhythm tracks and make a stereo cue mix on the work tapes using as few tracks as possible.

Generally speaking, I will make a stereo mix of the bass, drums and percussion on a pair of tracks. Then I will make a stereo mix of the keyboards and guitars on a separate pair of tracks. If there is a scratch vocal track, I will transfer a copy of that track across to the work tapes by itself.

Using this technique, in this manner, give me a virtually unlimited number of tracks to work with. It was not obvious at first, but it soon became apparent to me that with this method, it is possible to do much more than merely obtain additional tracks for overdubbing.

Probably the most important advantage of this system is that I can record many more genuine stereophonic images by using pairs of tracks, instead of merely single monophonic tracks. These stereo sound source tracks, can be kept in discreet pairs untill the final mix.

These true stereo images add much to the depth and clarity of the final production. I have a feeling that this one facet of my production technique, contributes more to the over-all sonic character of my work, than any other single factor.


My career actually began before stereophonic sound was of any interest to the industry, let alone the general public. This gave me the opportunity to do a great deal of experimentation, in stereo microphone technique, at my own pace. Consequently, I was able learn about what true stereophonic sound reproduction really is, before the commercial pressures came to bear. This also gave me a chance to learn what the emotional value of stereo imagery in music can do to increase the emotional impact of recorded music.

When we first started to record in stereo, our goal was to create a natural sound field, that had as its basis a real support of the music that we were trying to preserve. The big problem in modern music comes when we begin to overdub parts and layer the orchestrations.

The number of tracks necessary to realize the music can become astronomical in quantity, and thus becomes psychologically intimidating. This definitely need not be the case. I soon realized that this system makes it easily possible to have all the tracks I wanted to acomplish my musical objectives.

An additional and equally important value of this system, is that I can
also add a great deal more emotional impact to the final product, by not having to make any balance decisions, early in the production of a piece of music, that are wrong, simply because I couldn't make a good value judgement because I wasn't hearing all the parts of the music. In other words, I never finalize any pre-mixes, or balances in a piece of music untill I have heard all its' musical elements, and how those elements relate to each other, to form the whole emotion of the music.

When overdubbing vocals for instance, I can record all backgroud vocals in stereo, and not combine or pre-mix anything permanently, untill all the parts in the song are complete, and I can hear how all the musical values relate. I guess I could say that, with this method, I never have to erase a track!


The correct spelling of the process is:

Bruce Swedien

The preceeding is the text of a talk I gave in October, 1984 at a NARAS Los Angeles chapter luncheon. It is an effort to answer a subject that I am often asked to define. I had no idea when Quincy and I came up with the name that there would be so much interest in it.

Bruce Swedien

Contributors: mw, Bruce Swedien
Created by Bruce Swedien, 21st August 2006 at 06:28 PM
Last edited by mw, 27th March 2012 at 03:05 PM
Last comment by donsolo on 13th January 2008 at 07:07 AM
3 Comments, 19,634 Views

(3) Comments for: Acusonic Recording Process - Bruce Swedien Page Tools Search this Page
Old 12th January 2008
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donsolo's Avatar
I'm not 100% sure as to the benefits of this system in a digital recording environment where you have unlimited tracks and zero generational loss. It makes a lot of sense in terms of tape because of the transient loss due to playback.
Old 12th January 2008
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infopimpster's Avatar

What I read here, translated to the digital age, is "get a lot of mics on each source".

Watching the MJ "We are the World" session footage - namely, seeing how Bruce has him back up to get different mixes of proximity in the final mix - ties into this tactic as well, obviously.
Old 13th January 2008
Lives for gear
donsolo's Avatar
Ok, I get it better now. Thank you.

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