Do diffusers work to help with feedback?

I asked this question already but may have given too much info... Short question, do small plastic diffusers work in a small studio to cut down on feedback? Bill

Maybe slightly; but moving the mic closer or further from boundaries (wall, ceiling, etc) will probably do more, as will broadband corner absorbers. Diffusion needs DISTANCE to work; typically 10 feet or more depending on the lower cutoff frequency of the diffusor... Steve

I deleted your other post, it's better if you "bump" than keep adding other threads - here's what you wrote: Hi, I have a combo band recording room // practice room and use a Bose L1 system for the vocals. The room is about 12 x 12 x 8 ft high (maybe a little bigger but not much). I have acoustic foam panels up on all walls and the ceiling, then bass traps in the ceiling corners. Unfortunately I have to set low volumes on the vocals 'cause if I try to turn-up... feedback problems begin. Regardless, I have gotten some pretty good recordings (but want better), everything is mic'd except the bass and vocals have a direct feed as well as live sound then we use the live gtr amps w/live drums. But, I just cant hear my vocals well enough when we are playing "live" (which is how we record onto 8 tracks). So, 2 mic'd gtr amps, 2 mics on the drums, direct feed off of the bass and vocals so I'm getting ok isolation. The problem is weak vocal volume in the room to prevent feed-back. I have left some wall areas un-covered to reflect sound but I am thinking of placing diffusers on these spots... will this help break-up the sound waves without deadening the room too much and help with feed-back? Do I want to have a dead room? Yes, I know the "square" room is a real issue but short of moving, its what I have. Any help or comments would be appreciated. If your acoustic foam (is it REAL acoustic foam, or FoamByMail junk, or?? ) isn't too tightly attached, you might try TRIPLING it in a couple of the vertical corners, at least 3' wide - all that foam all over the room will take out all but bass and mids, so you get no sibilance in the vox; this helps make it impossible to understand vox when there's nothing left but "mud" - What will likely help (besides moving one of the walls) is to stack a lot of that foam in corners so it absorbs to lower frequencies, and takes less of the highs out of the room; then, experiment with mic positioning and direction, maybe putting 2-3 layers of foam JUST on the wall (probably about 4' square) where a mic is pointing. Next, check out this http://www.johnlsayers.com/phpBB2/viewtopic.php?t=2441 and try to locate your speakers so they're not in peaks or nulls, especially at any frequency you're getting feedback.l HTH... Steve

Steve, Thanks for the advice. I was not aware that diffusers need distance to work. And, distance is not something that I have in the room. I will also try to add some good foam in the corners layered as you suggest. Bill