In practice, that isn't that common. Distortion levels in speakers usually aren't nearly as much of an issue in speakers as response. There are expensive speakers with lower than average distortion levels and that's great, but with a balanced response. even relatively humble speakers can sound very, very good. With headphones, distortion is generally significantly lower and is even less of an issue.
The problem comes when you try to achieve 20 to 20 flat in a normal listening volume range. Not all speakers or headphones are capable of that, and no speaker, not even the best do that right out of the box.
It may be that in a practical sense, the speakers and headphones that are capable of being calibrated to produce a balanced response throughout the range are also the ones that already have low distortion. I don't know. But all I know is that I've always focused on response, and I've never had to address distortion. In fact, I've found dynamics to be more of an issue than distortion. Sloppy excursion on some speakers can even out the punch. But sloppy usually means unable to achieve flat too, because trying to push it into line will just create clipping.
In theory, something that measures the same on all aspects of sound reproduction will sound the same. In practice, some aspects are more important than others.
Reverb and delay are signal issues, not something particular to the speakers themselves.
Edited by bigshot - 1/12/14 at 12:53pm