Also, stereo rooms also tend to "start" with diffusion and home theaters tend to start with absorption for first (generally "most critical") improvement elements to room acoustics.

Not always, but that generalized statement is just from what I've seen, heard, read, or experienced.

Of course, a really good room has absorption, diffusion, and reflection, all at critical points that are mapped out.


Farewell - June 4, 2020