The receiver has a max volume setting to limit anyone from cranking up the knob to 100%. I set that limiter to 83% or 83 on an absolute scale of 100 which incidentally is the units' reference point. The receiver also has a limiter for subwoofer output as well but i leave that off/unlimited.
I've done some testing in the past and usually above the 90 mark distortion begins with my M60s (playback material dependant). As such, setting the unit to max at 83 means i always know it is well below a clipping point.
We tried a similar test with a friend's Tannoy S6s and an Anthem amp (225w/ch). We had the speakers hitting their excursion limits (only very briefly) w/o detectable distortion and at relatively low gain %s so we knew that his amp had more power than the speakers could consume. Hence, he really doesn't have to worry about distortion blowing his drivers (electrically caused damage), but he does have to worry about more direct physical damage to the drivers if he pushes them too hard.
