It was a woofer, so the low power seems to be the issue. The amp is triode/ultralinear switchable and I liked the triode mode better. I should have switched to ultralinear (i.e., 45 W) if I wanted to play loud, it seems.
How does a speaker blow out?
I don't understand how a speaker "blows" if the wattage of the amplifier is less than the upper limit of the speaker's limit. Then again, I guess I don't really understand what "clipping" is. The amp is 22w, I was listening at a moderately high level, there was a bass heavy section in the music, and then I heard the most painful noise coming from one the of woofers. Sad.