Clipping in a very simplistic way is like running DC power thru your speaker (for short periods of time). And since speakers (esp tweaters) can't cool down effectively when presented with a DC signal the voicecoil melts.
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Very popular explanation but it's wrong.
First, DC power doesn't hurt tweeters (unless you intentionly disable the crossover circuits).
Second, you can run DC power thru a speaker.
Third, there is no DC componet that results from clipping. It's at worst a square wave. If you severely clip a 1 kHz sinusoid at 10V, it will be alternating +/- 10 V, no DC component.
