Digital Processor Reviews

Sidebar: More Bits vs Greater Bandwidth

Contrary to what some industry pundits claim, the dividing line between "Red Book" and "hi-rez" audio is: 20-bit/44.1kHz—that is, 20 true bits, not mere nominal bits. I'm not saying that DSD, DXD, and 192kHz do not sound "better." I'm saying that most of the ills of "Red Book" sound can be traced back to its resolution of 16 bits. Resolution is more important than frequency response, I feel, in large measure because, for much program content, there isn't much musical information above 20kHz. For example, the workhouse rock'n'roll dynamic microphone, Shure's SM57, tops out at 15kHz.

Only the finest recordings of orchestras, pianos, or other acoustic instruments, made with microphones with extended frequency response and with high-quality preamps and converters, can show off the benefits of higher sampling rates. The best examples I know of, given my taste in music, are the Cypress String Quartet's 24/96 downloads of Beethoven's late quartets (www.cypressquartet.com). If you're shopping for a DAC, my advice is to focus on its "Red Book" performance because, to paraphrase what bank robber Willie Sutton denied ever having said, that's where the music is.—John Marks