Well, I agree your room is certainly Dead!
A dedicated room is a great thing to have, so you should take advantage of it. I'm kind of surprised that your speakers are sounding aggressive in that room with all that "deadness" around you.
A couple of other points:
How old are your Speakers? Are they fully broken it yet?
You certainly need to dedicate one seating position for yourself, with the proper seat height at the midrange-tweeter axis. I assume you're sitting in the front row, correct?
I would recline the other chairs behind you when not in use, but I can't believe that would be your problem, nor do I think your screen is the problem, because your room is dead enough, any deader and I would think that we need to get "CSI" down there.
I also don't understand why you have to move the speakers back and forth for movies and audio only. It took me 3 weeks to setup my speakers, with laser pointers calibrated by NASA>.
You need to find the best listening position for the speakers and then you should try to work the screen around the speakers and not the other way around. Sometimes too much toe-in can sound a bit aggressive, even if you're off by a 1/4 inch for each speaker, then that could translate to a huge difference. Tape on the floor is not accurate enough in my opinion. I'm telling you..., even if I look at my speakers the wrong way, they sound different.
Another point that I agree with is that you should strongly consider demoing a Tubed Amplifier.
If none of this works, then I think you may need;
"NEW SPEAKERS.... NEW SPEAKERS....NEW SPEAKERS!!
Road Trip!
Rich
