DIY wood diffusers


I'm having a freind who is a master wood worker make me some wood diffusers.Is there anyone who can give me exact mesurements for proven performance.I'm bassing them on a 2'x4' frame.I would like to know what depth I should make them and how deep and wide each cavity should be..
spaz
How about Charles Altmann approach
See the photo here
used by Mike Pranka of Dynavector Systems, New Zealand.

Mariusz
http://www.digitalaudiorock.com/cgi-bin/qrd.cgi

Here is a link to a calculator to design your quadratic diffusor.

John C.
Will quadratic diffusers make your room sound bigger.As I hear this statement often..