After reading about the benefits to treating first reflections I finally put 2 left-over 2 x 24 x 48 Sonex panels on my low ceiling at the reflection points. (I say left-over because a friend of mine ordered 8 panels a few years ago and only needed 4).
I mounted them to the ceiling crappily, I must admit. Here’s what I did and why. I glued some .25” x 4” basswood strips to the back of the foam for support. Then, I put a small plastic expansion anchor (#4, I think) in the center. Yes, that’s right, a 2’x4’ foam panel supported by a single screw in the ceiling. It works for now. I just wasn’t willing to drill any more than that in case the sound didn’t improve much. This also lets me rotate the foam so that I can experiment with the position a little.
Fortunately, the improvement is huge: better imaging, less sibilance, and more detail. But, the charcoal foam on the ceiling is ugly. So, if (non-audiophile) guests come over I can take it down leaving only a single 3/16 hole per side which is hard to see in the textured ceiling.
Ideally, I would like to get both a better-looking white panel and way to remove it without leaving a bunch of holes or dangling eyelets all over the place. After all, any blemish in a low ceiling hurts resale value more than in a high one. I’m not sure if such a thing is even possible.
