Skyline diffuser I made myself from solid cedar. It's probably too small relative to the size of my theater, but I think it helps with acoustics and looks great. Wasn't sure if
DIY: How to build a wooden Skyline Diffuser – The Point Of Creation
Amazon.com: Acepunch New Quadratic Skyline Acoustic Wooden Diffuser for Studio and Home Recording for Noise Insulation Soundproofing Panel 23.6" x 23.6" x 3.9" inches or 60 x 60 x 10cm AP1204 :