Denon, HK, NAD, and many seperates have no problems with m80's. For the most part any decent solid state AVR will be able to drive the efficient 80's as they are a very stable 4 ohm design. The question is to what level (loudness) you will be achieving before the receiver goes into protect mode.
In the past, Alan from Axiom has hinted that Onkyo's have had issues, this may not be true for the newer models coming out.
My Denon 2805 has no issues. Maybe some others will chime in with some feedback for you. good luck.
