A pair of PI AUDIO GROUP QRD diffusers for sale. Diffusers designed by Dave Elledge of PI AUDIO GROUP. Diffuser measure 47-3/4"x23-3/4".Diffusers are cut out of 2 pound plus density foam. A pair consists of one male and one female panel.Cost is $80.00 plus shipping and paypal fees for the unpainted pair. The diffusers are new.The diffusers will be shipped from 87120.