Need some pointers with room treatments

[Sir Terrence the Terrible]

AA, I don't know what the sound coefficients are of these boards are, but I'd like to suggest that you give these a try: http://www.atsacoustics.com/item--Ow...nch--1032.html

The below link gives the sound abortion factors for various frequencies for a broad range of materials:

http://www.bobgolds.com/AbsorptionCoefficients.htm

Hope this helps.

Best Regards,
Stan

Stan, you are headed in the right direction with 4" thickness of you have full range speakers. Learning about the coefficients of the different thicknesses of the foam(if you understand it) is the best approach to doing this.