adidadi,

Been doing some thinking re: your blown driver situation and just skimmed back through the thread.

Given that you have a heavily dampened room, employ MRC (don't know how many filter and where), and your overload protection isn't working, have you considered that the "thermal compression" that's taking place in your D5200 drivers is due to possibly faulty amps and electronics. It seems remote that both in a pair and even your center channel, but possible that there is a bad batch of speakers out in the field.

The overload protection, I believe, works based on an impediance differential measured from the drivers, which change over frequency. The fact that you're running your system hard is contributing to that fact. Perhaps Jason needs to see the back panels of the speakers and test them.

Just a thought...

Jay