I just noticed your left speaker back fires on a window. Go up and shout at
the window, and see how your echo sounds..... Pretty hurtful. I see you have a
curtain. That can help a little. For serious listening sessions I would hang a
panel over the the window. In my own system room, I find hanging my
antique quilts over my windows helps some. An area rug would help on
reflections too. Find fine ones cheap at eBay.
Have you experimented with separating the speakers more?