In reply to:
probably the best analysis available online of why tweeters can sometimes be damaged when amplifiers are driven into clipping by very high level low frequency signals is found at the St. Andrews University site . Both the "harmonics" and "compression" hypotheses are analysed and other possible contributing factors are briefly discussed. Apparently a combination of factors may be responsible.
I have to admit... as soon as the crazy equations come out, I have to force myself to keep reading. There's really not much "new" that I didn't touch on in my two posts. The main theories are a combination of:
-HF creation by clipping of the LF (ie: harmonics)
-Rise in the HF level of the original signal which – although limited by clipping by an amount similar to that which occurs at LF – rises to a high level. (compression - though his tests show that highs don't run off as bad as one would think)
-Leakage of LF power. (that really depends on the crossover type - and I think you'd see some real differences in which manufacturers' tweeters go "sizzle" if this were a major factor, but... bundled with the other reasons - it can only hurt!)
-Non-themal effects due to an increase in the peak displacement or accelerations. (actual physical driver excursion and acceleration aggrevating the other causes - though tweeters now are cooled much better than they used to be, I haven't seen a tweeter give off a little puff of smoke in... 15 years?)
Bren R.
