The M80s were tested at 1200 watts according to this article by Alan Lofft.
http://www.axiomaudio.com/archives/power.html
Axiom tech support had told me in the past that I could easily drive them at 1000 watts even though they are rated for 400 watts.
I have not actually turned up the volume high enough to light up the clipping lights on the QSC amp. But the 1100 watt QSC provides a lot of headroom, especially for sound effects like gunfire! I don't think I will damage the speakers by listening to music at reasonably loud levels, even though I have a large HT room.
