Whoa! The thread awakens. smile Thought my spring rear wall diffuser update would be it.

The sidewall polys were installed prior to the sidewall absorbers. The absorbers made a much more impactful benefit to listening. That said, I am happy I went with the polys for esthetic reasons. At the time it was hard for me to quantify with measurements or give a definitive subjective impression. The room was still pretty lively.

One thing the polys did do was take the ring out of that sidewall to sidewall area in the room when testing rt60 with balloon pops. It was impressive actually how much it improved flutter issues. Gone even before absorbers.

If I revisit these areas I will do a shallow QRD design for the sidewalls and wrap in AT fabric. People say QRD diffusers dont work in small rooms, or they arent beneficial compared to absorbtion. In my experience they are a great solution when trying to preserve room energy. They sure are a lot of work compared to polys though.

If you are thinking of an overhaul while shifting your sidewalls and mains around I would encourage any diffusion. A deep front wall QRD was an incredible improvement for my setup.

I'm not very good at concise answers.... If you are ever on the island you are welcome for a listen. smile