This is not necessarily an answer to your question, but is my experience. I spent years listening to what I'm sure was room problems.... boomy bass, poor imaging, etc., in my living room full of drywall and windows. One day I took the whole system down to the unfinished basement. Down there is insulation on a couple of the walls, cement floor with some carpet, and exposed floor joists. The difference listening down there is amazing. All of the things that were bugging me are gone. It's a crude example, but it proved to me that I need to either learn about treating my living room, or stay in the basement. As of today, I'm still in the basement, till I figure out how to slove the problem without spending big money on acoustic panels.