Surround Professional, October 1998, Volume 1, Issue 1, by Robert Margouleff

The author builds a 5.1 mastering suite in his living room in order to remix a series of classical Quad master tapes for contemporary DTS 5.1 release.

As a record producer/engineer in the 70s and early 80's, Malcolm Cecil and I worked in four-channel Quad with Stevie Wonder, along with many other artists and producers. By 1974, working at the old Record Plant in Los Angeles, we had built a dedicated quad room (Studio B) with the help of Tom Hidley and John Storyk and we routinely monitored in quad. The music worked beautifully in the studio as discrete 4-channel but the delivery technology (vinyl records) couldn't support it faithfully. Now at last, through 5.1 Digital Surround, we can get back that sense of space and create music with greater emotional depth, space, and feeling.

Recently, I have been involved in a major project for DTS; restoring and mastering classical recordings originally produced in quadraphonic during the fate '70s and early '80s. Many of these recordings were cultural milestones and were beautifully recorded. Sadly, they were crumbling into dust. Unlike paper, on which our civilization has preserved its history and which lasts for hundreds of years, tape is only good for about 25 years. Because of the limitations of tape as a storage medium, we are rapidly losing our modern musical heritage and history. Through the support of DTS and Angel Records, we have been able to not only rescue and restore many of these important recordings, but also to enhance and reconfigure them into 5.1 Digital Surround. My belief is that 5.1 brings a new power to this music, and will create a new and larger audience for the classical repertoire and preserve them for the future.

I  would never have thought after nearly 25 years of making R&B, rock and pop records that I would find myself back at my roots working on classical recording, but this was a major reason why I recently built a 5.1 surround studio in my living room.

I have a large living room, 16-feet wide by 24-feet long. The listening position is in the middle of the room on the diagonal. All of the speakers are at ear-level on stands. There's a fully-carpeted floor with an oriental rug on top. There is one heavy cloth wall hanging and several over-stuffed pieces of furniture. With several large windows overlooking a beautiful park, it's a comfortable living room, that is acoustically a good-sounding space.

The studio centers around a Yamaha 02R V2, two TASCAM DA-98's with a pair of Prism 2024 bit-splitters to handle 20 & 24 bit encoding, three TC Electronic Finalizer Plus, five Genelec 1032As and a pair of M&K M5000 subwoofers. I also use both Millennium and ADA DTS decoders to play back my DTS-encoded 5.1 Digital Surround compact discs. I believe that this is the first project studio totally dedicated to 5.1 Digital Surround audio production and mastering.

Back to the Future

The first thing that I do is to review all of the tapes in quad to see if there are any problems. Since the speakers are full-range, I always want the quad recordings to be able to stand alone without the addition of center and subwoofer channels. This is for those purists who want to hear the original quad recordings.

I never take away anything from the original recordings to create the center and sub, but only add to enhance what is already there. At this point I have to make a decision whether to use Sonic Solutions for 'NoNoise-ing,' editing, and repairing. Some recordings need this and some do not. If this is needed, I take the original 24-bit quads to Charlie Watts at Mondophonics, because Sonic Solutions is highly specialized and requires an artist like Charlie--who is an expert. This is the only operation I take outside my own studio. Once the master has been prepared, I am ready to start working to EQ, balance and create the center and subwoofer channels (note: A normal CD is 16-bit, and DTS masters are 5.1 channels of 20-bit resolution, which certainly makes a difference in terms of dynamics, resolution, and detail).

The Signal Path

I normally receive 24-bit digital transfers which have been generated from the original quad analog masters. From my source DA98 w/Prism interface, the audio is digitally input (AES-EBU) to four channels of the O2R in 24-bit. The O2R dithers the 24-bit signals down to 20-bit. Then the audio is digitally mastered, including the creation of the center channel and the subwoofer channel. The audio is assigned to six outputs and sent to the second DA-98 w/ Prism so that the 20-bit data can be arranged for storage on a 16-bit DA-98 tape. From the second DA98, the 5.1 tape is played into a Sonic Solutions system where the PQs and index points are made, and is encoded into DTS for mastering onto CD, Laserdisc, or DVD. I would like to point out that the recordings never leave the digital domain from when I receive the original digital transfers, to the final 20-bit, 44.1kHz DTS encoding process.

The Coherent Center

What I try to do is create the image of another microphone, as if it had been placed in the center of the orchestra, using some or all of the quad channels to derive coherent center information. I normally use the stereo buss for this operation, since I'm not using it for anything else. The stereo panners are full left and right on whichever of the four channels I am going to use, to create the center image. For DTS, the channels are set up in AES-EBU pairs: LF-RF, LR-RR, Center-Sub. The stereo buss feeds the input of a specialized digital unit developed several years ago by Malcolm Cecil, from a basic design by John Bedini (there were two experimental units built for  digital processing, and I have one of them). The result of this is not simply A+B, as it removes all out-of-phase   information (extreme left and right,) and leaves only the fully inphase information--which happens to be the true center information. This is returned to channel five. The subwoofer information is also derived from the stereo buss mix and then EQ'd and balanced, and sent to channel six via a low-pass filter set at 120 Hz.

To monitor playback of the 20-bit, 5.1 mix from the destination DA-98, the signal comes out of the destination DA-98, through the Prism box into the console, and then through another set of faders. They, in turn, are assigned to the Yamaha's eight-channel, analog l/O card which is plugged into slot number 4 on the rear panel of the console. Since I have no use for the input part of the card (I have no analog 8-track machine), the analog card has been modified--cut in half--to carry only the eight analog outputs. My first six aux busses are assigned to six outputs on that card which becomes my analog output monitoring section to feed the monitors. The monitoring section of the O2R is useless for 5.1 monitoring, as it is set up for stereo. Of course the beauty of the Genelec 1032As and the M&K's is not only their sonic purity, but also that the speakers and amps are all self-contained (a little more convergence, if you see what I mean). This also leaves me with 24 AES-EBU digital I/O's..

Artistically Speaking

As a producer and mastering engineer, my goal is to be accurate and faithful to the music. It is not possible to make a 5.1 remix from a stereo master. I must have an original, true quad or multichannel master. I have found in the classical world that there were rarely any multichannel (8-,16-, 24-track) recordings made. Performances were recorded directly into stereo and/or Quad during the live sessions. I have to determine which are the real Quad recordings, as many selections that are listed as Quad are actually stereo with reverb added to the rear channels later or in SQ or QS matrix. These unfortunately have to be disregarded. When making my A & R selections, I try to choose a complete representation of their catalog, not just a list of 'greatest hits' to represent each major composer or conductor. For example: "The Complete Orchestral Works of Debussy", with the French National Radio Orchestra under the baton of Jean Martinot (a five-disc set). There is quite a bit of detective work involved in finding what recordings are available. Happily, there are many performances recorded during this brief period when the labels spared no expense to create first-class quad recordings.

Generally the content of the conservatively recorded quad tapes is with the orchestra in the front two channels, and the rear channels mostly carrying the ambient sound of the concert hall. Much to my delight, I have found in many of the recordings, the engineers, producers, and conductors stretched the limits and came up with innovative recording techniques. Some recordings have the front stereo pair close to the conductor, so that you really feel the orchestra, much as the conductor would: very wide with a lot of detail. Or, as in Aida, the first opera presently being mastered (by me) in 5.1, the female chorus and instruments are in the rear channels only. It's fantastic!

Who needs a home theater when you can have a surround project studio sitting right in the middle of your living room? I sit down with a cup of tea in the morning and turn on Mozart. I can make any little EQ and level changes I want. Since I work "by the project," I can spend as much time as I need to make it perfect. When I'm done, I save all my setups in the scene memory of the O2R, so I can always go back if I want to. Then, I'm off to my next project. This room is really kicking some classical butt and I can never get enough of it!

Known for his Grammy Award-winning work for Stevie Wonder, Robert Margouleff has recently worked on surround remastering projects for Paul McCartney (Band on the Run) and Alan Parsons (On Air), and 5.1 remixing restoring projects including the Marvin Gaye, Anthology (Forever Yours). He can be reached at robert@micasamm.com.