I found In my rectangular room 12" of the wall and 12" of the ceiling full length of the rear wall and corners with absorption panels sounds the best. Like yours, my rear wall also has household objects that act as diffusion. +1 curiousjim... the clap method was how I arrived at my room correction. My system is very lively and this final treatment went a long way in taming Klipsch Heritage speakers at the higher volumes I prefer. Good luck.
Question: Sound Treatment behind the Listener?
I have treated the 1st and 2nd reflection points and I have sound panels between my speakers. I also have tube traps in all 4 corners, but I am not sure what (if any) should be done with the wall behind the listener.
That wall presently has a DIY rack system that holds about 5000-6000 cd’s. I believe it helps scatter the sound. But I’m not sure if that is the right approach.
So, what are you guys using on that wall? Diffusion, Absorbtion, Reflection? Anything else?
I would appreciate your thoughts.
ozzy