[hollywood_steve]

Small rooms also need absorption at all low frequencies, not just those related to the room's dimensions.

That was my goal with the corner panel trap described in my original post above. According to everything that I have read, the variable depth of a corner trap makes them the best solution for broadband absorbtion.

I may also add a standard rectangular panel trap on the rear wall of the room, next to the doorway (that's the only wall space left except for the area on either side of the nearfields, where I am in need of some serious diffusion to kill a classic example of flutter echo caused by two parallel walls in close proximity.) I was initially thinking of a deep (6 to 8") trap with 1/2" plywood and at least 4" of 703/705 board for the panel next to the door.

This brings up another question. All of the panel trap performance charts in the Everest books always show 1/2" plywood as the thickest panel material and the 1/2" thickness always results in the ability to trap much lower frequencies than traps with 1/4" or 1/8" panels. But I have never seen a panel design utilizing 1/2" plywood. At some thickness, the plywood has to stop acting as a membrane (given a fixed 2ft x 4ft panel size). Is 1/4" the thickest practical size or is it 1/2" or more? In theory, there is no easier way to increase the traps ability to handle lower frequencies than to increase the thickness of the front panel; but where does practicality take over from theory? (assuming the added weight is not an issue)