yea... you said you were playing it at about 80% for an hour or so... that most likely caused overheating in the amplifier which could have caused major clipping when that certain bass tone hit. It was probably a frequency the woofer wouldn't handle and since it was up so high and was probably heating up, it just blew.
Try taking a 9v battery and connecting the negative poles to the negative of the speaker and the positive to the positive. If you see the speaker move/jump, then its still alive, but since its making a popping sound makes me think that its damaged other than the cone.
Talk to EricB about this... hes a real techy speaker guy. HEHE