Hi Eric
My Room A is enclosed on the outside of the drywall with Roxul Safe N Sound. The Ceiling and two walls. This was done to insulate the room sounds from the rest of the house. The other two walls are against the house walls with regular insulation on the other side of the drywall.
Something to consider, just throwing it out there.
Curtains of various heavy and light materials work and look good. I am using them extensively in the adjacent room. You could hang one ceiling rail behind your listening chair. Curtains, offer the extra advantage of hiding extra speakers. :^)
You could also use one Magneplanar Tympani speaker behind your chair right now - try it. They absorb. I know guys with Acoustats doing this.
Cheers Chris