How Much Are You Missing From 20khz to 45khz?

The issue is phase shift. That is why bandwidth is nice.

The less phase shift, the better the imaging.

Phase shift is caused by group delays that in turn are caused by a rolloff in the equipment. They can have artifacts to 10x higher than the low frequency rolloff, and 10X lower than the high frequency rolloff.

This is less of a problem in speakers than electronics, but its still an issue.

Bifwynne, no speaker has anything like what I would call a linear curve. If the bumps aren't too bad often that's pretty good :)