Variable bass Absorber (@Left Bank)

  • Thread starter Thread starter Tonio
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T

Tonio

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So what is the purpose of the gap on the ply about 3/4's down?
Or is it a gap?
This is the design of John's for Left Bank Studios...
http://johnlsayers.com/Studio/PDF Files/Variable_Bass_Absorbers-diffusors.pdf

I assume the top and bottom on the ply side is enclosed/sealed , yes? If so, why the cloth?
I don't quite understand what the detail shot" Through centre and ends" is explaining.


Could John or anyone else explain, I really like the design heck the photo's of Left bank show how appealing it is. All I have to do is convert the measurements. Gotta make me a few!!!

TIA

T
 
I don't think that's a gap. It's just a trim detail.

The curvilinear part swings open to fit into the concave area of the slot resonators. When that part is swung back, it exposes the cloth and it's underlying insulation. Being able to swing it "open" or "closed" is what makes it "Variable".

If the whole mechanism were stationary, you'd have only one type of treatment. In John's design, you can "vary" the type of diffusion/absorption by swinging that part open or closed.

Open, and you have absorption, closed, and you have diffusion for that part of the mechanism.

Imagine a row of those on your studio wall, and you can begin to see how it would be possible to "tune" the room with that many possibilities of absorption and/or diffusion.

Clear as mud?

I'm sure John will let me know if I mucked up that explaination. :p
 
You were spot on Michael - yes it's diffusor/slot resonator when closed and an absorption wall when open. The slot resonators are between each section and are curved to take the curved fronts when they fold over.

I must point out that these were VERY expensive as they were built in an external joinery shop and use exotic timbers :)

cheers
JOhn
 
John, what kind of timber?

With your permission, I'd really like to employ these in my new studio, and I was thinking of using Birch wood for the timbers, and maybe a sitka spruce for the curved plywood panels.
Or maybe just all birch.

How well do you think that wood species would work?
 
My bad,
I just realized that they swing open:o duh

Hench the variable. They sure are beaut !nice wood!!!

Unfortunately I don't have a router, so patching up different moldings would be hapazard.

After converting they are @ only 6'x3' . Are they tuned to a specific
frequency? I really like the slat concave design- real nice.
Hey, would convex slat to the contrary be of any use?

T
 
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