OTHER TECH

Perfect sound forever. Well, some people will tell you that the compact disc doesn't offer either. Diehard audiophiles complained from the day the CD was first introduced that it sounded cold, metallic, and sterile compared with the LP. And the discs can deteriorate over time, if ever so slowly. While years of refinement have led to a marked improvement in overall sound quality, the complaints have never really gone away.

The LP-hugging golden ears weren't the only ones who felt the CD fell short of the ultimate in sonic reproduction, though. Convinced they could do better, CD co-developers Sony and Philips went back to the drawing board to create a format that would address audiophile concerns. And the Super Audio CD was born. Offering higher resolution than the original CD, compatibility with existing CD gear, and both stereo and multichannel playback, this next-generation compact disc has the potential to lure people away from downloads and other lower-fidelity, on-the-run playback options and back to dedicated music listening on high-quality systems. But the difficult task of establishing the Super Audio CD (SACD) as the CD's successor has only just begun.

What Lies Beneath To understand SACD, you have to know something about the Direct Stream Digital (DSD) technology that forms its foundation. Judging that pulse-code modulation (PCM), which has faithfully served the CD for almost 20 years and is the basis for both DVD-Video and DVD-Audio, had reached its limits, Sony and Philips devised DSD to offer both greater dynamic range and more extended frequency response than CD-standard PCM, while also allowing for future development. In fact, much of the early effort to promote SACD has been more of an effort to promote DSD - to encourage record producers and recording studios to chuck their analog and PCM digital gear and embrace DSD instead.

There are three key things you should know about DSD: First, "direct stream" means, at least in theory, that the bitstream can flow directly from the initial encoding of the analog source through the recording process, onto the disc, and through playback without using the filters necessary for PCM recording and playback. Second, some producers and engineers feel that DSD recordings have an "analog" warmth and presence that were lost in the transition from LP to CD. And third, any opinions on DSD and SACD should be taken with a grain of salt. No independent, double-blind listening tests have been done to compare DSD recordings with analog or PCM recordings of the same material.

Two Will Get You Six Because Sony and Philips have spent most of the two years since they launched SACD actively courting the high end, which pooh-poohs anything beyond two channels as hopelessly gauche, very little attention has been given to SACD's multichannel capability. The early releases were all two-channel audiophile chestnuts, primarily from the Columbia/Sony Music catalog. A few surround titles appeared from smaller labels late last year, but the only sop thrown in the direction of the mainstream was the Virgin U.K. reissue of the original quad mix of Mike Oldfield's classic Tubular Bells.