Post by cyclecamper on Jan 14, 2017 17:51:08 GMT
My space will be multi-purpose; for critical listening, performance practice, a bit of recording, and maybe some video eventually.
But there are guitar and bass amps lining the walls. It adds up to about 40 drivers. But there are never more than about 4 or 8 in use at any time, often only one or two drivers.
I have an adjacent equipment room, but it's getting rather full of repairs and log-term projects. I had planned to just wheel things in & out.
BUT the back wall has an island with a countertop. Under that countertop I was planning to put some fractal diffusors or bass traps. But it occurs to me that I could just wheel 4 to 6 guitar amp half-stack bottoms (with 4 12" drivers in each) under the counter bar, and wire some resistive loads onto some 1/4" plugs and let the speakers operate in reverse, as huge-diaphragm microphones turning acoustical energy into electrical energy into heat. I'm thinking they would act as damped panel absorbers. Of course, not all the surface area is cone surface. But there are some huge potential advantages. For one, they would be comparatively broadband with much of the compliance determined by the electrical load, which would be controllable by the value of the load resistors chosen. For another, the load could be easily tuned with inductors and capacitors, easily tailoring the frequencies absorbed. What a lovely convenient way to tune an absorber! On the other hand they are not particularly efficient, but neither are damped panels and loaded mass diaphragms etc.
Of course good drivers are more expensive than a damped panel, but I can get cheap used Fender GE412 4X12 bottoms for $100-$190 any time (obsolete, they came with a horrible head). They're not the greatest speakers but as absorbers they would probably work pretty well. Of course they are large and consume a lot of space in the room. And absorbing lower frequencies will require quite a large array of drivers. Still, it's price-competitive and free for me since I already have them. They probably won't absorb very high frequencies, and the rest of the speaker baffle board area between and around drivers is just reflective. Some of my bigger sealed bass bottoms are mostly just big boxes of stuffing, and would make decent absorbers even without plugging in a resistive dummy load; the cone mass just lowering the absorbed frequency. If I ever get the room empty for some measurement, it would be interesting to see what happens when I wheel in a few SVT bottoms and a couple of stacks...
But there are guitar and bass amps lining the walls. It adds up to about 40 drivers. But there are never more than about 4 or 8 in use at any time, often only one or two drivers.
I have an adjacent equipment room, but it's getting rather full of repairs and log-term projects. I had planned to just wheel things in & out.
BUT the back wall has an island with a countertop. Under that countertop I was planning to put some fractal diffusors or bass traps. But it occurs to me that I could just wheel 4 to 6 guitar amp half-stack bottoms (with 4 12" drivers in each) under the counter bar, and wire some resistive loads onto some 1/4" plugs and let the speakers operate in reverse, as huge-diaphragm microphones turning acoustical energy into electrical energy into heat. I'm thinking they would act as damped panel absorbers. Of course, not all the surface area is cone surface. But there are some huge potential advantages. For one, they would be comparatively broadband with much of the compliance determined by the electrical load, which would be controllable by the value of the load resistors chosen. For another, the load could be easily tuned with inductors and capacitors, easily tailoring the frequencies absorbed. What a lovely convenient way to tune an absorber! On the other hand they are not particularly efficient, but neither are damped panels and loaded mass diaphragms etc.
Of course good drivers are more expensive than a damped panel, but I can get cheap used Fender GE412 4X12 bottoms for $100-$190 any time (obsolete, they came with a horrible head). They're not the greatest speakers but as absorbers they would probably work pretty well. Of course they are large and consume a lot of space in the room. And absorbing lower frequencies will require quite a large array of drivers. Still, it's price-competitive and free for me since I already have them. They probably won't absorb very high frequencies, and the rest of the speaker baffle board area between and around drivers is just reflective. Some of my bigger sealed bass bottoms are mostly just big boxes of stuffing, and would make decent absorbers even without plugging in a resistive dummy load; the cone mass just lowering the absorbed frequency. If I ever get the room empty for some measurement, it would be interesting to see what happens when I wheel in a few SVT bottoms and a couple of stacks...