I'm not familiar with them, but I gave their product line a look.
http://www.piaudiogroup.com/Sound_Diffusors.htmlThat first diffuser set on the page, the AQD:
Sound Diffusors
AQD diffusers by PI AUDIO GROUP.
The price for two pairs of unpainted 2'x 4' AQD panels cost $160.00.
Price does not include shipping.
Two pairs of diffusers the benefit of two matched pairs is very beneficial when treating a room acoustically.
At least one matched pair can be used in the front center to create a front center image. The second pair and be used at the rear wall,behind and slightly angled when using open baffle speakers,or on the side walls combined with absorption panels.
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They don't look very deep, which means they don't dip down into the mids much. They look like they have many fine steps, which is great for high frequency. The only thing that detracts from them is that they don't have "wells". What the wells give you a time delay that helps your ears define the original source from your diffused reflection.
These would be great for breaking up flutter reverberations, but I don't think they are as good as a proper QRD diffuser.
Then again, any diffuser is better than none!