If you reach out to
Lukasz at Seven Audio in Poland, he can make you properly calculated BAD (Binary Amplitude Diffuser) "scatter plates" from 1/8" birch or maple plywood to mount over the absorbent faces of any broadband absorber panel. Lukasz will custom cut the exterior dimensions of your scatter plates to perfectly fit whichever broadband panels you have and even with the overseas shipping the cost is surprisingly reasonable. My landed cost for eight 49" x 25" unfinished maple ply plates worked out to about $50 Canadian per plate.
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I finish sanded the scatter plates, stained them grey to match my existing room decor and treatments, and applied a spray-on satin sealer before nailing them to the router-beveled 3/4" plywood frames of my DIY broadband panels.
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And the completed panels in use. Lukasz also made the 1D Fractal QRD diffusers seen in a 5 panel array on my rear wall along with the three 2D QRD diffusers seen on my ceiling.
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