My brother does a lot of sound engineering and is building his own studio. He was talking about having me build a "flutter free diffusor" http://lonelyraven.zenfolio.com/img/v5/p349964626-3.jpg
I don't know the depth of the grooves yet. I'd like to make it out of solid wood. It would be aprox 4" wide, 1" thick and up to 96" long. I think I have an idea on how I would do it, but I'd love any input.
Aaron