Edited: Raven ran the numbers through QRDude for me (its windows only and I am Mac) and gave me the QRD23 design which I made two of out of cheap underlayment board (but its very straight) and 1" wide foam. The "chamber" never sounded so good.
I told him today if I had to do it over again, I would do the whole room in QRD23's. I have a mixture of 7's, 13's and now the 23s. The 23s destroy the sense of any walls in my room. Still playing around with their placement.
I am running both the OBs and the mock monoliths. Both sound superb in my 12.5 X 16 room.
I have a desk in there as it doubles as my office. Thinking it has to go.
Reading this post makes me proud, excited, and laughing, especially at that last part. I seem to remember one of the first time at your house when I finally felt comfortable offering suggestions to you, I said those shelves have to go, window needs to be plugged, and if you're really going all out, the desk has to go.
All you guys reading this, have no idea how amazing Palomino's room sounds.
As I've said for 18 years now, diffusers are the key to unlocking amazing imaging and frequency balance in a room.
Just building and deploying my one QRD29 diffuser has improved my sound as much as a good firmware update on my DirectStream. And that's on top of already having a DirectStream with good firmware (LOL) and a room full of smaller diffusers.