Anyone else here interested in, or built, or even heard Folded Well Diffusers??


I was introduced to the Folded Well Diffuser while looking around Agon, I forget who had first mentioned it, but I thought I might have a go at building some for my listening room.

RPG have submitted a patent for extended bandwidth folded well diffusers,

ReadScapes have a DIY page with many options to choose from, I went with the 40mm Prime number 7 version

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I made some myself using 3/4'' plywood. The dividers I used 1/4'' maple ply which was lacquered on one side from factory. I've noticed the dividers have bowed and warped on me once installed. What's his name says you have to use cherry, I'm sure wood species will make a difference, I'm gonna use red oak next go around. 

@brunomarcs - I have made QRD17 also out of cherry wood. When I re-sawed the beams into the dividers I ran them on a joiner each time to get a perfectly flat surface to run along the guide, and still it wanted to bow a little. Certainly not what you’ve described though.

Have you considered making a comb that will have teeth that hold the divider fins in place at the correct pitch? I’ve seen a few diffusers using that method to get the centers perfectly aligned, maybe it could work for you?

I find building with wood to be so much fun, and almost therapeutic even.

How many did you make of these?
Where did you position them?
What were your listening impressions please?

@slaw - I suppose they will be collectively, reasonably heavy.
I made them 4ft long, and they are about a foot wide. Yeah, a dozen or two of them will get some mass, they weigh just under 23lbs each. The 5ft tall QRD 17 diffusers I made took two of us to lift, and I was admittedly the smaller fella doing the lifting.

I suspect in order to be reasonably rigid though, the structure needs to be made of a material that will not yield too much?? I’m still learning about diffusion, and getting better woodworking skills in the process.

@oldhvymec - it looked interesting enough to make this crazy builder have a go at them. I already have 6 built, then it occurred to me that I should ask in here if anyone one else found them beguiling enough to build, it appears there is.

@brunomarcs - I just also considered using popsicle sticks with the well width as the length cut, it would probably help to go from one side to the other and use them to prop it back into shape, for little investment?