Hi Spoiler,
It's possible to overdrive any woofer--especially if you have any electronic bass boost engaged, like a +3 dB or +6 dB boost of the bass control on your AV receiver or preamp. But you say you were using the direct mode and bypassing any tone-control circuitry, right?
It's extremely unlikely to exceed the excursion limits with the M80s' woofers, or at least I've never heard it happen. And I've been present when several Axiom colleagues of mine shut down three of five 350-watt per channel monoblocks driving M80s (plus two subs, an EP500 and EP600). The SPL levels were insanely high and I had to go out on the deck outside the house after a couple of minutes.
Once you near the output limits of an amplifier running at very high SPLs, remember that only a 3-dB increase in output (subjectively, that sounds just "slightly louder") will require twice as much power from what the amp is producing. So if your amplifier was hitting 200 watts per channel on peaks, and you turned it up just 3 dB, you'd need 400 watts to prevent the thing from clipping.
In your case, I suspect it was occasional clipping of the Outlaw mono amps. If anyone is into clean, undistorted, extremely high sound levels, I recommend power amplifiers of 300 watts per channel or higher. We routinely test the M80s at 700 watts per channel and more.
Regards,
