I'll check the volume on the iPod...that's a good idea. All my music is encoded with Apple Lossless.
Update: 5/1/05...I have the volume turned up all the way on the iPod. A minor improvement in sound through the system, but still low volume. It's good enough to serve as background music, and that'll do for now. Still, I'd like to know what Wilson Audio used for their set-up when they demo'ed their Watt Puppy 7 loudspeakers with the iPod as a source.