Among the paradigm shifts that will certainly occur in the upcoming century is a fundamental expansion of the way musicians and engineers conceive and produce their sonic art. This was made apparent at the Surround 2000 conference, held last November in Los Angeles "for those who create, install, and produce multichannel sound." The primary focus of the conference was multichannel music, and it certainly opened my ears to some new and exciting possibilities.
Of course, movie soundtracks have used more than two channels of audio for some time, in both commercial cinemas and home theaters. The most common configuration uses five discrete full-range channels (front left/center/right and rear left/right; see Fig. 1) and one low-frequency channel. Such a system is generically called 5.1 (see "Square One: Surrounded by Sound" in the December 1999 issue of EM). However, virtually all audio-only music recordings are still strictly stereo. With the proliferation of home-theater systems and the development of new storage and retrieval technologies, this is about to change.
In "Tech Page," I've written about two of the most important new technologies: Super Audio CD (SACD) in the March 1998 EM and DVD-Audio in the July 1998 issue. Unfortunately, nobody at the conference had one of the few existing prototype DVD-A players to demonstrate, but that didn't stop everyone from talking about this format. In fact, many of the engineers I spoke with said they are working on various DVD-A projects, recording or remastering six channels at 96 kHz with 24-bit resolution.
Sony and Philips were demonstrating a multichannel SACD on a prototype player. (Previously, only stereo SACDs and players have been available.) Most of the demo material consisted of live orchestral and choir recordings using five full-range channels (no low-frequency channel), all of which sounded spectacular. With my eyes closed, it was far easier to imagine I was sitting in a concert hall than it has been with any stereo recording.
This sensation is central to one of the most interesting debates at the convention: whether to place the listener of a surround recording in the "audience" or in the middle of the band. Most attendees agreed that for classical and live recordings, listeners should be in the best seat in the house. (Who wants to sit in an orchestra's woodwind section and get blasted from behind by the trombones?) With this approach, the rear speakers primarily convey room ambience.
However, studio-based multichannel pop projects offer some previously unavailable creative opportunities. In studio recordings, unlike live recordings, the instruments and vocals are completely isolated from each other, which lets the mixing engineer put them anywhere in the 5.1 sound field. Early attempts at this approach were hokey and distracting, but engineers have learned a lot in the past couple of years, and the demos I heard at the conference were very rich and involving.
Looking even further ahead, TMH Corporation (headed by Tomlinson Holman of THX fame) demonstrated a 10.2-channel audio system with ten Genelec-powered speakers and two Whise subwoofers. The demo included live recordings of a thunderstorm and Handel's "Hallelujah Chorus," recorded with 16 mics and mixed to 10.2 channels played from two synchronized DA-88s. The effect was stunning.
One thing was perfectly clear at the Surround 2000 conference: the future of music recording is multichannel. As more consumers install home-theater systems and as engineers learn how to take full advantage of the new formats, we will start hearing recorded music that goes as far beyond stereo as stereo went beyond mono. It's a great time to be a recording musician.