Dave Moulton /
02.06.2002
Hi-Res Listening
Alert readers will recall that, about a year ago, I wrote a series of pieces on high-resolution audio and its place in the scheme of things. My position was that, especially for television, it wasn’t particularly important.

I took a fair amount of abuse for that position and got into a fairly lengthy exchange with a top-level post production guy as well as Bob Dixon of NBC Sports. All this was duly reported in the pages of TV Technology. You remember, right? Sure.

Well, a year has passed – a tumultuous year. And one of the many bits of tumultuousness in my life was the resumption of a life project that has been lurking in the background for 20 years or so – composing music. And that composing, in turn, led to a major upgrade of gear.

So now I am the proud possessor of the latest, hottest Pro Tools workstation, capable of at least moderately "hi-res" work (24-bit, 48 kHz audio) and a lot of tracks. Further, I’ve got some pretty hi-res plug-ins (including SpectraFoo, which means I can really measure the res) and a hi-res reverb (Lexicon 960), all working within the workstation platform.

All of this talks to the real world through a Yamaha 02R console, which has 20-bit resolution.

More to the point, I’m busy composing some pretty high-tech, hi-res electronic music. This is music that uses a lot of tracks (64 plus) for a long time (up to an hour) with a lot of automation, a fair amount of signal processing, a tremendous amount of Surround Sound stuff (all my music is multichannel with a vengeance) and a huge dynamic range (uh, 96 dB!).

What this means is that I’m really and truly walking the walk these days, not just talking the talk. And so I thought I’d share with you what I’ve noticed, now that I have been dragged kicking and screaming into the 21st century of hi-res audio.

DO YOU HEAR WHAT I HEAR?

The first question has to be, of course, can I hear a difference with all this increased resolution? And the answer is, interestingly, yes. Well, sort of yes, anyway.

CDs passed through the workstation sound distinctly better than CDs converted to analog by the CD player. Soundfiles imported into the workstation sound really nice on playback.

And what do "sound better" and "sound really nice," mean? To me, they mean slightly richer, more luminous, with greater depth and detail than I normally experience.

But it is only "slightly," suggesting that the difference is, in fact, pretty small.

And finally, I have to ‘fess up, I’m not sure I could reliably pick out the difference all the time in controlled blind comparison tests. It may "sound really nice," but is it "enough nicer" that I could pick it out 95 percent of the time?

I’m not at all sure that it is.

AUDIO CRYPT TALES

But there’s more to this. At one point this summer, a colleague (Roger Talkov of DVD Labs) brought in a major label classical surround 24/96 DVD-A he was mastering so he could check it out over my surround monitor system. We used a fairly cheap consumer DVD-A player and just plugged it into my surround monitor path.

Surprise! There was a lovely soft "depth" and musical richness to the sound that was both distinctive and satisfying. Further, we were able to compare a (Grammy-winning) pop 16-bit/44.1 kHz CD against a 24-bit/96 kHz DVD-A release of the same album and observe that a similar difference seemed to be present – a softness, a kind of delightfully crunchy musical depth that replaced the "edge" on the recording. Like I said, it was really nice.

What causes it remains a question. For reasons I’ll get to in a minute, it can’t be the bit depth. My speakers are good to 17 kHz but roll off steeply above that, so I’m dubious that it is the increased bandwidth.

The stock converters in the cheap consumer player can’t be any great shakes. So it remains a question, a good question.

Meanwhile, the music I’m working on has some serious dynamic range. One piece that I recently finished actually starts at -90 dB FS and slowly rises to -60 dB FS (and then, VERY slowly, crescendos all the way to 0 dB FS – but that’s another story).

What’s interesting is that it is usually very hard to hear the -90 dB FS stuff. Hard enough that one early listener called me to wonder why the music didn’t start for the first several minutes. And when I got the stuff mastered for DVD surround, the mastering facility called to ask me where on the tape the piece started – they weren’t sure, even though I had it logged.

Now, -90 dB FS is the 15th bit – some 9 bits and 54 dB above the 24-bit digital black noise floor of the workstation.

WHAT DOES IT ALL MEAN?

And the truth is, we can’t hear even that crass "lo-res" bit, under any reasonable playback circumstances, without anything else going on! Interesting, eh?

What’s the point? Well, I personally think that the point is that we don’t understand, yet, what it is that we’re doing with hi-res.

Our hi-res efforts are, apparently, affecting the quality of sound in ways unrelated to bit depth or bandwidth. We speculate, rant and dither about what "those ways" are, but the truth is that we really don’t know. And – truth be known – it’s pretty subtle, however pleasurable.

A second, more important point, to me, is that Surround Sound is very powerful medicine – much more powerful, more pleasurable, more meaningful than hi-res. And yes, we can instantly hear the difference that it makes. No question at all.

My final point is that you can, if you wish, check all of this out for yourselves.

Four of my pieces are on display through Feb. 10 as "virtual sound sculptures" at the Chapel Gallery in Newton, Mass. If you’re in the area, stop in and check them out – no charge. The pieces are six-channel Surround Sound compositions (I use an overhead channel in addition to a standard 5.0 array).

Various listeners have told me that these pieces are really very beautiful. I’d love for any of you who can to have a listen and tell me what you think. For info on the exhibition, contact SeanMacLean@earthlink.net or http://www.bostonsculptors.com/.

Thanks for listening.


Comments
Post New Comment
If you are already a member, or would like to receive email alerts as new comments are
made, please login or register.

Enter the code shown above:

(Note: If you cannot read the numbers in the above
image, reload the page to generate a new one.)

No Comments Found






 
Featured Articles
Discover TV Technology