Welcome to the Axiom forum Jhas. Thermal shutdown is the most common reason for an amp to stop working. Make sure you have plenty of space around your amp. You could try placing a fan on the receiver as a test. The Axiom M60's and VP160 are both 8ohm nominal impedance which should present no problem to the receiver so it may be you got a defective unit. How large is your room ? I have M80s and a self made version of the VP160 and my Denon AVR3311 had no trouble driving them to high levels full range so I suspect something is amiss here.
Richard
