iceman16 said:
Does distortion usually "harm" an amp or speakers be either minor or major?
Very possibly.
Driving a speaker with a heavily clipped signal from an overdriven amplifier can be dangerous, Such a signal is virtually a squarewave with a power that might be higher than the rms output of the amplifier. Furthermore, the voice coil may be driven and held outside the magnetic gap (the flat, top of the squarewave), no longer subject to the cooling effect of the airflow and the magnet assembly, the coil can burnout in a split second.
Even worse, some amplifiers produce a small but significant DC offset when heavily into clip, again this forces the coil out of the gap and causes burnout. Of couse amplifiers driven hard for long periods may overheat, if the amplifier is not adequately protected the components in the amplifier may well be working outside their safe operating area and actually burn out.
These are of course at the extremes of amp/speaker behaviour, but any dealer will tell you 'monday morning' stories of blown speakers and customers saying they were not playing that loud and the amplifier is less powerful than the speaker rating etc, etc.
So perhaps not that 'extreme' after all!