Quote:
Originally Posted by
Kyle P. Gushue
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VPR
"This Absorber technic is invented and well documented by the German Fraunhofer institution. The VPR Absorber is made with a Don Caruso WLG035 100mm thick porous absorber panel and a steel plate. The Absorber thickness, the steel plate size and thickness plays a role and is calculated to have most effect on your target frequency. "
https://www.don-audio.com/Acoustic-room-treatment-guide
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The reason you don't see rooms covered with diffusion and VPRs is because it would leave a gigantic hole between the effective range of the VPR and the lower limit of diffusion (which is shroeder frequency at best).
You would not have enough surface area to manage the entire range below the diffusers limit, even if one knew how to calculate the array properly according to the modal distribution and strength in the room.
If your goal is to experiment and learn with end result taking the back seat, by all means follow thru on your idea and the necessary additional treatment it will take. Or stick with simple tried and true, and be much more confident that the end result will be good.
If I have 1200x3600mm arrays or larger of Jens Eklund's Optiffusor they will go down to 300Hz according to his measurments. A 1mm steel plate VPR will absorb that high, but not much under 70Hz, if I remember correctly, (have to double check), 1,5mm maybe not, 2mm steel place absolutely not. So the gigantic hole from range of VPR to lower diffusion limit might not get to be so big
It's a LIVE room and not a control room, so decay in bass and controlled return from mid range and up, is a priority, even frequency respons in a given spot is not a priority at all. I will build it as planned and take it from there... i will have some wheeled/mobile velocity based absorbers to test with to. So I have material for 7 x 1,25 to 1.5m wide and 2,5-3m high VPR's and 3 full peiod 1,2x3,6m diffusors. Might not get to be perfect but it wont cost mpre than 5 grand...