Pass X150.5 vs. X250.5

I have owned two Pass amps. The meter at 11:00 isn't pushing the amp all that hard. So I'd be a little surprised if the harsh peaks you are hearing are attributable to the amp being overtaxed. I therefore think you should look elsewhere in the system for the source of the harshness, before you consider changing amps.

Bryon

I agree that you should look at the room. IME, some adverse room effects, particularly in the high frequencies, are inaudible at lower volumes, but quite noticeable at louder volumes or during peaks.

Here is a 10 second test: Standing in a couple different places in the room, clap your hands loudly. What does the decay sound like? Is there ringing? You may have a flutter echo that is bothersome only on peaks.

If you do have a room problem, then adding diffusion at this point may be a better idea than adding more absorption, but both should have a significant impact.

Bryon