Plans to Build A QRD a bit like RealTraps Diffuser

Can anyone point me in the direction of a video of plans to build a QRD like the real traps diffuser where it doubles as an absorber.



I'm sure I remember seeing the guy on the video sawing up thin pieces of rigid fibre glass to put in the various well depths of the absorber behind the membranes.



Many thanks!



Oliver

Plans to Build A QRD a bit like RealTraps Diffuser