Music in the Round #1
Stereo—from the Greek word stereos (solid)—implies three dimensions, not two channels, and applies equally well to multichannel sound. But stereo has long been encumbered with the common meaning of "two-channel sound." In this column, I will accept that definition of stereo, and will use MCH for "multichannel" stereo.
I recall vividly my discovery of plain old two-channel stereo (POTS?) back in the 1950s—in an upstairs demo room on Radio Row, later the site of the World Trade Center, in downtown Manhattan. A pair of monster Bozak speakers, driven by McIntosh amps and a ReVox tape deck with staggered playback heads, reproduced Beethoven's Symphony 7 as I had never expected to hear it outside a concert hall. Width and depth were no longer the products of loudness, but were actual dimensions that contained musical information. Nor did the weight of the ensemble obscure the voices of individual instruments. And yet, as impressive as that experience was, something was missing. The performers spread across the proscenium were vivid and solid, but I was not included in that space. The performers were in one acoustic environment; I was in another. It was as if the listening room had grown a large, almost completely transparent window onto the performance space.
Taking the next step—through that window—has not been simple. It has required the development of technology to deliver much more information without sacrificing the superb resolution we've come to expect from stereo, and to accurately convey the sound of a live performance event. Quadraphony, the abortive multichannel splash of the late 1970s, failed as a serious medium on both counts. The signal quality of the additional channels on SQ and CD-4 LPs was compromised. Worse than that, most quadraphonic recordings were engineered as if to take the term "surround sound" literally—they placed the listener not in the studio, concert hall, or at a jazz club's front table, but smack-dab in the middle of the ensemble itself.
This had to be something other than an aesthetic decision; it was probably something like, "Let's do this because we can," or "Let's make sure that the customer knows it's surround." Quadraphony failed because most musical purists found it offensive, and most casual listeners didn't care enough about it to bother.
In late 1999, the arrival of a full five-channel Meridian system gave me the chance to sample MCH again, and I scrounged for every MCH disc I could find. But the sound tantalized without consistently satisfying. To begin with, there were few music discs to choose from, and even fewer were of mainstream music by mainstream artists. Moreover, the mixing and balancing on most were as disappointingly perverse as they'd been on quadraphonic LPs. The worst offenders were the initial stream of nearly unlistenable DTS rock and pop reissues, which had arbitrary and inconsistent instrument placements in the rear channels that recalled the "Let's do this because we can" philosophy.
But a few exceptions—DTS discs from Telarc and Dolby Digital discs from Delos—finally gave me a glimpse of what multichannel might sound like when done right: the true realization of stereo. All it had taken was 40 years and $75,000 worth of equipment.
Where are we now?
Less than five years later, we now have improved resolution with DD and DTS media. Most significant, we have DVD-Audio and SACD, media that offer both two-channel and multichannel signals of truly wide range and high resolution. We are enjoying the best stereo sound ever from new high-resolution recordings and hi-rez remasterings of the great performances of the past. Moreover, all the technical advances in two-channel reproduction apply equally to multichannel sound, so any argument about relative signal quality is moot.
Multichannel reproduction, however, is still problematic and controversial for many audiophiles. Some are put off by the cost of several more channels of the same high quality as their present stereo reproduction. (The state of the economy and of your checkbook are outside my mission.) Some are deterred by the proliferation of formats with different numbers of channels (4.0, 5.0, 5.1, 6.0, 7.1...), the complexity of setting up lots more equipment, and the issues of bass management and low-frequency effects (LFE) channels. Some are haunted by the ghosts of Quadraphony and crude demos based on movie soundtracks. Some simply deny the potential improvement of MCH over stereo. I hope to address all of these concerns. Let's examine the last first.
It takes two+ to tango
The best argument for multichannel sound is that it takes more than two channels to realistically re-create the experience of listening at a live music event. The sounds of the event come at a listener from all directions; each sound is transformed by the head and ears according to the angle from which it comes (footnote 1), then transduced by the inner ears (cochleas) into neural impulses. The brain in tries to decipher the myriad neural impulses by combining auditory, visual, and other information, all of which contribute to how we perceive what the space is, where we are, and where the musicians are.
Footnote 1: This acoustic transformation is sometimes referred to as the Head Related Transfer Function, or HRTF.