Sorry, I've been away for a few days. Thanks Alan and Dr Toole, what a great explanation!
I also thought it had more to do with reflections more than the amp, specially after playing around with bed sheets and pillows, but wasn't really sure why, now I know
Unfortunately, I don't have a dedicated room, I use my living room that is 20x11 ft. To answer Dr., I seat in the center of the long side wall and my TV and speakers are across. My couch is against the wall and on top of that, behind the main listening position is a bay windows so no acoustic panel can be there. As for the sides, they also unusable for acoustic treatment, one side is open towards the hallway, the other has a bay window. The only thing that could really be done (on top of bringing the mattress, pillows, bed sheets, etc.. into the living room
) is adding a bit of furniture and putting thick curtains on the bay windows.
Thank you all for your help, this has been great.
