The Assumption Presumption
Self-styled Hitlerite Frazier Glenn Miller, Jr. didn’t, when he shot up a couple of suburban-Kansas City parking lots last week, and got two Methodists and a Catholic. (Lest anyone think I’m making light of that outrage, I am not. I weep bitter tears for those families, their communities, and for my country. Sure, every nation has its nutballs, but what other arms its as well as we do?)
Yet assuming is just what you and I do every time we cue up a “hi-rez” audio file from the growing collections stored on our music diskdrives. Sure it sounds better: It’s got bits up the yinyang and is oversampled to a rate approaching microwaves.
But does it? Science tells us no, that 16-bit quantization yields dynamic range of 128 dB (a LOT), and that Dr. Nyquist long ago proved that 44.1 kHz sampling will reconstruct waveforms up to (almost) 22,500 Hz. (Not approximate: reconstruct.) Few who made it much beyond high school calculus will argue either point.
When Sony first introduced the world to the Direct Stream Digital coding format—DSD, the massively oversampled one-bit basis for SACD audio, and now widely used in mastering digital in many professional environments—they invited groups of audio journalists (there were more of us back then) into various Sony Music control rooms to compare Redbook CD masters to SACD ones, under (ahem!) scientific conditions. Audible differences there indeed seemed to be, but they were very subtle indeed and frankly hard to hear, facts to which all parties, including Sony, agreed. And these were the guys selling the thing.
And yet hi-rez audio (“HRA”) certainly does seem to sound better, at least in many instances, than the CD. What’s going on? I don’t know, but that’s never stopped me from analogizing.
Twenty-five years ago us audio buffs snapped up thousands of “audiophile” LPs at prices several times those of the original record-store vinyl, because “they sounded better.” And they really did, and do. Anybody who’s ever A-B’d a Mobile Fidelity copy of Dark Side of the Moon to an original will concur: more bass, more highs, greater dynamics, quieter backgrounds, etc. And you don't have to be Aura d’Oro to hear it.
Those records were re-mastered: the original two-channel mix tapes were retrieved, and re-engineered without concerns for the many commercial strictures imposed upon the LP format. These included playability (put too much bass in a groove, particularly an inner groove, and a mass-market stylus/tone-arm will distort mightily or even physically skip), playing time (more signal, especially bass, meant shorter records, though less signal meant less dynamic range and higher noise), and they were pressed on higher-grade (quieter) vinyl.
The mastering process in our digital age is much less intrusive, especially today, but there is still potential for improvement in many cases, with different (less) equalization and dynamic-range control, especially in the pop world. In the jazz and classical spheres, many times the CD mastering processing is pretty minimal, and at least some HRA files are simply up-sampled from the two-track master, while DSD files, at least some of them, may simply be the master. I’m a big fan of DSD hi-rez, though I make no claims of personal immunity to confirmation bias or suggestibility. Just the same, we probably can all agree that less processing is better than more.
But here’s my point (always supposing I have one: in the early days of any new audio format, the programming self-selects for sound quality. E. Power Biggs and his massively overblown pipe organ launched the LP format; Telarc’s 1812 canons the compact disc. Now, HRA download sites overwhelmingly still feature good-sounding recordings created from the outset by people who cared more about audio quality than about making their track the loudest on the FM dial. Not too many people are going to line up for hi-rez purchase of, say, the first Kinks album (though I believe you can!), which might as well have been cut to a wire-recorder. In short, it’s the recording, not the format, and when we buy an HRA file we’re voting as much for the original's sound-quality-first recording practices as for bits’n’kilohertz.
I can’t go back and revert an HRA file to a master tape for comparison. I can, however, report an analogous experiment, one I’ve performed many times. Ripping my best-sounding LPs to CD-standard digital audio yields files that, under direct A-B, I believe I can just bleedin’ barely distinguish from simultaneous vinyl playback. And that’s using my audiophile-average turntable, cartridge, and phono preamp, and the encoding engine in my four-year-old civilian iMac. Plug in five-figure vinyl gear and workstation-class encoding, and I very well might get results that weren’t distinguishable at all.
Or so I assume.