I can see how 'under' powered amps might have been able to blow some tweeters now and then but such talks tend to get over blown to the nth degree. To me, too much power on hand, if not used wisely, is a surer way to blow speakers. I guess most of us who work in the industry would have noticed there are tons of boom box/ghetto blasters have their volume know turned fully clockwise all day long, with fully distored sound for the sake of SPL, yet they seem to last forever. That is at lease one proof to support the camp that believe in too much power is more often the culprit than under power. At the end of the day it does not mattere which camp you belive, the golden rule is still, if you can hear distortion turn it down, except for those ghetto blasters in shops and canteens etc.