Thanks guys,
I've fiddled with it a bit more today. I'm not sure exactly what your saying about the preamp distortion. I'm pretty sure it's not the source output; my Sony NC600 DVD player turns off any local decoding of the source when using a digital output, and my digital coaxial cable is properly rated.
I've been thinking about the power ratings. 200 watts is probably the maximum peak power the M22Ti's are designed to handle and the Denon can probably push beyond that at times since 90 watts is its continuous rating. Setting the speakers to small instead of large makes it take up to +10 or so to distort, but the loudness seems reduced. So I can't say I know exactly what's going on still, but they play plenty loud before distortion sets in so its not a big deal. I just wanted to be certain that I had my system set up properly and I can't find anything wrong.
If I make any great discoveries, I'll let you know.
Thanks again,
Matt