Dilemma.... My setup is M60v1, QS8s, and a new VP-160 v4, Ep-500 5.1 system

My last receiver was a Pioneer Elite VSX-23TXH and I experienced clipping with that receiver. Ended up being one of the M60s that was replaced by AxiomAudio.
4 years later we upgrade to a new VP-160 and I upgrade my receiver to a Pioneer Elite
SC-77.

Watching a Elton John concert on BD, bang.. auto shutdown.......ran it in stereo mode loud and no SD. Hooked up center and one M60 and ran in stereo mode loud.....no shutdown. Re checked all wires...zero problems. Did notice in the setup my setting for center channel was "Large" along with the fronts. Rears are in "small". I changed center to "small". Cranked a music Dvd in surround and no problem at 0.00 db
Watched the Hobbit last night at a decent volume....Bang....auto shutdown twice mad

Is it the Pioneer that can't handle Axiom's impedance???? Guess I will return it to Bestbuy and try a Marantz 7008

Techies I need help!