While I hope that the new amp fixes the issue, I'm skeptical. I recently read in another thread a post by I think Audiokinesis that describes situations in speakers where the voice coil gets too hot and starts to limit the bass response of a speaker. When reading that, I instantly thought of this thread. If that's the case, then it's the speakers, not the amps that are causing the issue.
Fishing, let us know how things progress.
Fishing, let us know how things progress.