BREAKING THE 5.1 BARRIER by Peter M. Bracke

I remember my first real day of film school vividly. Having suffered through two years of community college with nary a film course taken, I arrived a fresh young scrub to the decadent shores of Los Angeles, ready to embark on the USC School of Cinema-Television experience. Being young and perhaps a tad naive, I had countless visions in my head of lackadaisical hours to be spent making short films, writing scripts, and of course raking in the eventual millions of dollars. Needless to say, I never even stopped to think about the actual classes I'd have to take. All a mere aside on the way to movie stardom. What, me worry?

After settling into the campus, I trudged off to my first class, which was to be a semester-long introduction to film sound. Hey, no problem, right? I can set up my own hi-fi at home, so this won't be too tough. Sitting down in the impressive auditorium, the lights dimmed and I was treated to a few minutes of the opening to the original Star Wars (long before the advent of CGI, thankfully) without the finished sound. I recall it vividly, all the cheesy "pops" of toy guns and the ridiculous-sounding on-set dialogue spoken in funny British accents. The crowd loved it, and I thought "hey, film school is going to be great!"

Then the instructor is announced, and it turns out to be "some guy" named Tom Holman. An audible hush falls over the auditorium, and there are cheers. Since I was a young idiot and didn't know anything at the time, I leaned over to a fellow student next to me and whispered "Who's Tom Holman?." He chortled "Duh! The guy who invented THX!." Cue incredulous reply..."Oh."

So for the next semester, I was treated to an intensive, take-no-prisoners lesson on the ins and outs of film sound. My vast hi-fi knowledge of RCA plugs and Dolby Pro-Logic stood no chance against the formidable tasks laid out by Mr. Holman's rigorous course, and I never knew what hit me. By the end of it all I realized I wasn't much of a sound guy, and was quite pleased to have just scrapped by with a "B-." In all, I think Mr. Holman was just being kind.

Like all good professors, though, he was always personable and friendly, and I have enjoyed occasionally correspondence with him over the years. So, I was quite excited this past week when I was invited to the offices of the TMH Corporation to hear a demonstration of the his new 10.2 surround sound system, still currently in development. Funny enough, though, walking up the stairs to his office, I recalled my original film school experience, and for a second a bit of that same nervousness came over me. Would I have to take a test after the demonstration?

Beyond 5.1

Thankfully, no exam this time, just a few of the inevitable questions. Quite simply, why go beyond 5.1? Because, with the advent of DVD-Audio, "the focus has been entirely on the technically impressive numbers, the benefits of which are negligible at best in terms of an increased experience for the listener" explained Mr. Holman. Indeed, the DVD-Audio spec has retained the traditional 5.1 (five full-range channels and one LFE subwoofer channel) arrangement, focusing instead on upping sample rates, dynamic range and compression ratios, with arguably little regard for the law of diminishing returns. At some of the higher quality levels of DVD-Audio, it may be true that only those lucky enough to possess dog hearing would be able to hear the difference.

The approach of TMH Corporation is instead towards increasing the number of channels, coupled with high technical specs to provide a more fully an involving and immerse experience for the listener. But can the finalized DVD-Audio spec go beyond 5.1? The answer, which may surprise some, is yes. The format allows for alternate subcarriers aside from Dolby Digital, including PCM and DTS, as well as the Meridian Lossless Packing (MLP) compression scheme, to increase storage efficiency and achieve optional longer playing times without lossy psychoacoustics-based perceptual coding. A DVD-Audio disc could conceivably carry a full 10.2 soundtrack with maximum specs of around a 60 kHz sample rate, 20 bit dynamic range and a 6.57 megabytes per second bit rate. Play time would be roughly 100 or so minutes, and would still leave room for a 5.1 Dolby Digital soundtrack for compatibility purposes. With such base specs, 10.2 certainly becomes a viable option. (Editor's Note: No specs for any DVD-Video based 10.2 were available, if even possible.)

Speaker Placement

TMH has supplied us with a diagram with an experimental version of the speaker placement for their 10.2 system. Actually utilizing 14 separate speakers (see below for more details), the TMH surround sound system would be the first to utilize what many have wanted for years, namely two ceiling-mounted front speakers to expand the soundfield vertically as well as horizontally. In addition, two banks of three speakers flank the front, 30, 45 and 60 degrees off center from the listener on each side. A center speaker dead ahead complements the front end.

The surrounds, perhaps surprisingly, are only made up of three speakers, one each to the left and right, and another dead center behind. Note that though a 10.2 setup would suggest 12 speakers total, the TMH spec accounts for an additional set of dipoles slightly above the rears for the left and right surrounds, so a complete TMH 10.2 system would actually utilize 14 individual speakers. Lastly, directly to each side are placed two LFE subwoofers equidistant apart, for the ."2" in 10.2.

Perceptive readers will notice that the front end is proportionally larger in terms of speakers and sheer amount of sound than the surrounds. Contrary to what many would believe, Tom Holman illuminated that "simply placing a series of speakers equidistant apart in a 360 circle would not faithfully create a fully immersive soundfield" like one would imagine. This is due to the difference in the way humans hear sounds coming from in front as opposed to those coming from behind. Thus, TMH spent extensive time and effort in planning the layout, and assures that a fully enveloping and non-localized soundfield would be created in a full 360 degrees. Certainly, though, the arrangement may be the most controversial part of the whole 10.2 spec.

Though the DVD-Audio format is relatively fluid, a caveat is that in order to output a 10.2 signal manufacturers would have to deliver equipment capable of delivering the higher number of channels. As the TMH 10.2 system is still in the experimental phase, no such plans exist, and it is decidedly premature to speculate on the hardware side of the equation. However, TMH is actively demonstrating the technology across the country to members of the industry, the press and the public, so further developments may be forthcoming.

The Demonstration

With the technical specs understood (or, in my case, nearly understood), it was time for the main attraction, a full 10.2 demonstration. I was taken to a test room exactingly set up by TMH that contained the full experimental speaker layout as illustrated (again, see the diagram). A very nice leather couch was placed in the optimum position for the listener (and very comfortable it was, too), and all the lights were shut off. My friendly TMH guide David Margalia then exited the room to leave me to experience the demo on my own. With no room light at all, it was so pitch black I couldn't see a thing even with my eyes open. For a second, I thought perhaps this was all a big joke and I was about to be beaten severely about the face and neck. But, luckily, the demo began without bodily injury.

Since there is no 10.2 material on the market, TMH created a roughly 15 minute or so demo of a variety of aural material (a special mention should be made of the aforementioned Mr. Margalia, who was also responsible for creating some of the very impressive demo sequences heard). Immediately, after just the simple vocal introduction, I could tell they were using some top-notch speakers, at least compared to my lowly set up at home. The first part of the demo was an impressive use of ambient outdoor noises, namely some insects and wind, followed by a thunderous rainstorm. Quite frankly, when it arrived it scared the crap out of me! Again, it was a testament to the quality of the speakers, as well as the mix, that I could feel the bass right in the seat of my pants. The depth and clarity of surround environment was immediately apparent as the sounds of the storm echoed around me. The quiet ambient hum of the wind and insects was very natural and "transparent." All I needed was some iced tea, a bug swatter and a good cheap paperback and I'd have been set.

But, next came the near-infamous "flyover" test, where some sort of craft flies from the front of the soundfield to the back. In this case it was a helicopter, and TMH wisely let the imaginary craft's approach play out slowly. Though again I have never been a total sound guy, I have to admit, I felt a real palatable sense of anticipation as the helicopter slowly approached from the front, careened over my head and then sped out the back. Amazingly, I could not sense any sort of localization of the sound source as the helicopter made its journey, and for a few seconds it genuinely felt like it was on top of me. The seamlessness of the effect truly was impressive.

The next segment, though, was probably the most startling. A recording of a piano tuning, it started with some quiet, nuisanced plinks of piano keys. However, I was not aware that it was also a recording of the piano tuners themselves talking and moving around the room. So, and I'm being completely honest here, at the beginning I thought I was really hearing workmen outside the room. It was here that the accuracy of the 10.2 system to render movement in all directions, not just flyovers from front and back, really came into its own. I was actually going to get up (not that I could have found my way to the door anyway) and ask if the demo could be stopped until the workmen left. However, after a minute or so, I realized what was happening, and I have to admit I was completely fooled by the transparency of the sound. It really was rather amazing, and definitely the best discrete surround presentation I have heard.

Another impressive segment involved a recording of a choir, which made strong use of the overhead front speakers. Since in this case the recording was meant to replicate a presentation coming from the front, I didn't worry so much about trying to avoid localizing the rears. The use of a vertically heightened pair of speakers made an immediate difference. I could not directly place the lovely sounds of the choir at any one "level', like one can do with sound setups that align all the front speakers on the same horizontal plane. Without a visual aid in the blackened room, it was a simple wall of sound coming from the front, which was very pleasing and lifelike. The surrounds were used in this sequence, and were especially notable when the piece ended and the crowd applause came on.

However, this was the one area where I was questioning the 10.2 system. To be honest, I was able to locate the three rear speakers ever-so-slightly in the mix, and did notice a little bit of "space" between the two rears and rear center speaker. I think this may be because though the three rear speaker placement overall creates an enveloping soundfield, the sheer number of front speakers and force of sound still pulled me to locate the sounds as coming from the front. Plus, the place of the couch oriented me towards the front, and thus I often found myself consciously (and subconsciously) attempting to "anchor" the sound directly ahead.

But, in all, I was genuinely impressed with the demo. To be honest, though I enjoy Dolby Digital and DTS 5.1 soundtracks, this was simply more enveloping, exciting and enjoyable an experience. And any of the caveats about the surrounds at times should be tempered by the fact that this is still in he experimental phase.

Applicability

As impressive as the demo is, thoughts must turn to the applicability and use of the TMH 10.2 system. Obviously, any system requiring 14 speakers will be limited for the most part to the high-end market. Add to that the need for a substantial room size to house the equipment, and new DVD-Audio players and discs specifically designed to take advantage of a 10.2 soundtrack, and the mainstream appeal becomes decidedly limited.

However, talking with TMH, it is clear that as the existing 5.1 home theater experience gets more and more like the theater (and often exceeds it), there is a definite need to be filled for an experience that goes beyond 5.1. Obviously, theatrical presentation could most readily benefit from a 10.2 surround system. However, during the demo, I became most excited about more avant-garde or atypical possibilities. A few times, in order to consciously distract myself from placing sounds to the front of the room, I got up and spun around until I was dizzy and lost all sense of direction (luckily, I didn't spin out of control, crash into the speakers and electrocute myself).

It was here, especially during the early rainstorm bit, that I got a new sense of excitement I've never experienced before from listening to surround sound. Because, with most presentations, either a film, concert or televised event, you are always facing front and center and thereby psychologically oriented to one direction. However, I wonder how such a 10.2 setup could be used on everything from amusement rides to clubs to performance art. Perhaps I'm demented, but I actually enjoyed being disoriented and confused, and not knowing what direction the sound was coming from. It was quite a lot of fun, though what practical or commercial applications could come out of such an approach is debatable.

Outlook

For me, I've always enjoyed 5.1 soundtracks and found them adequate for home use. However, I was not particularly impressed with the new Dolby Digital EX system debuted with The Phantom Menace, and I do believe we will see surround sound systems that utilize a great number and more varied placement of speakers. Though I do wonder about the viability for the home market of such a system, I was pretty much blown away by the clarity, spatiality and effectiveness of the TMH 10.2 demo.

Currently, there are no set plans for any introduction of TMH 10.2 products. However, interest is already building around the system, so don't be too surprised to hear more from them in the future. They certainly are pushing into territory few others have tried, and I, for one, would welcome new and progressive surround sound options like the TMH 10.2 system. Finally, the breaking of the 5.1 barrier is here.

For more information on the TMH Corporation and TMH Labs, visit their web site. Special thanks to Fritz Koenig and TMH for their help with the writing of this article, and Mr. Holman for the B-.