Back in the late 1980s, it seemed a good idea: Separate a CD player's transport section from its D/A circuitry so that each could be optimally designed, and, as D/A technology improved, the sound of your CD player could be upgraded by replacing the outboard D/A processor. The catch was that the transport and D/A chassis needed to be connected with a serial data link: S/PDIF in optical or electrical flavors, or balanced AES/EBU. To minimize the number of cables required, the format of that link embedded the clock data within the audio data, which rendered the link sensitive to interface timing uncertainty, or jitter. (See "Bits Is Bits?," by Malcolm Hawksford and Chris Dunn.)

Gross is about to play an excerpt from a recording of John Rutter's Requiem. It's a piece that challenges just about every aspect of sound reproduction: there's an orchestra, a soprano soloist, a chorus, a pipe organ, and the acoustics of a large concert hall. Wimpy speakers need not apply. I listen, expecting to be underwhelmed.

Whoa! The low bass of the organ so fills the room that I look for subwoofers in the corners. The orchestra and chorus have great presence. There's a believable sense of space. These are some speakers! How much?