To quote Alan Lofft:
http://www.axiomaudio.com/boards/ubbthreads.php?ubb=showflat&Number=229287#Post229287

"Under those conditions, the M80s sustain up to 800 watts dynamic peaks with no damage. Driver destruction occurs at 1200 watts."
The operative words being "dynamic" and "peaks".

Those who have long enjoyed such privileges as we enjoy forget in time that men died to win them.