Quote:

I rarely watch movies at more than -6db but even at that point high frequencies are harsh and it quickly becomes fatiguing.



This is not a problem with the electronics.
Either the volume is too loud in such case anyone's ears tire after awhile, or you are not enjoying the tweeter section as much as you once did.
Although it can be considered blasphemy by some, a 1-2dB dip in some of the upper end spectrum can 'sound' nicer on the ears. This is what i found with the Monitor Audio speakers that i auditioned.


"Those who preach the myths of audio are ignorant of truth."