Peter, I'm not the expert you are hoping for, but I'm pretty sure you are confusing clipping/distortion with the speaker actually bottoming out due to the speakers ability to handle power. What is being described here - and I don't think we have this story cleared up - is the M80 producing the exact sound it is getting from the amp - distortion. Why the 876 would be distorting/clipping is a more difficult question, and I could not tell you don't worry about it. In Denon I trust. But the build up to this point - and I mean no disrespect to the original poster - does not lead me to believe you are getting great info here. We have a gumbo of current limiting, EQs, and many unknowns. Don't jump off the ledge yet.

Panny 3000 PJ, 118" Carada, Denon 3300, PS3, Axiom QS8, PSB 5T, B&W sub, levitating speaker wire