Anyone like Susan Parker's marble sphere speakers?
How much does markble cost and where can one buy it?
Tom
How much does markble cost and where can one buy it?
Tom
In my system I had a vibration feedback problem. Marble shelf didn't help sounded just like glass. Hardwood helped, isolators helped. Isolators on Marble didn't work either.
It would seem that a speaker housing should be non resonant or accoustically dead, not just heavy. The Marble I had (a slab) would ring if struck by an object
. Sandstone - now that might be OK
It would seem that a speaker housing should be non resonant or accoustically dead, not just heavy. The Marble I had (a slab) would ring if struck by an object
. Sandstone - now that might be OKWood is cheaper than aluminum (I think) and much lighter than concrete. You can build an inert enclosure with wood, and that's all that really matters, right?
Aluminum seems to work just fine in the Krell LAT speakers. Of course, whether or not there's an audible difference between the aluminum and some well braced MDF is another issue entirely.
Aluminum is stiffer than wood, but has less internal damping.
Many ways to skin the cat... I prefer the easiest and cheapest method that produces a "good" skinned cat. 😉
Many ways to skin the cat... I prefer the easiest and cheapest method that produces a "good" skinned cat. 😉
There was a little speaker manufacturer from britian who lined his wooden speakers cabinets with either lead or steel. Doing that really made them inert!!
Dave
Dave
what about taking 2 1/2 inch pieces of mdf and spreading a thin 1/4 layer of concrete between them to connect them? seems it woudl be pretty rigid.
That wouldn't work either. The MDF would wick the water out of the concrete. The wet MDF would fall apart and the concrete would become brittle.
I was thinking of building a large square box for a subwoofer. partially Fill the box with concrete and then infating a weather ballon inside the box until the walls are just a few inches thick. Make sure you reinforce the concrete with some steel mesh, insert befroe baloon. When it hardens, deflate the balloon, dissasemble the box, unless you plane on using the wood as a finish surface, in which case tapcons to tighten the box. and remove the external bracing that you used to hold the form.
Now you have a dense, heavy cabinet with absolutely no parallel sides as the inside should roughly be a globe, depending on ballon size of course. Make your self a nice thick front baffle and chip away the concrete to the opening size required. Tapcon the front baffle into place.
Then invite the nieghbour hood around to help you move it.
Regards
Anthony
Now you have a dense, heavy cabinet with absolutely no parallel sides as the inside should roughly be a globe, depending on ballon size of course. Make your self a nice thick front baffle and chip away the concrete to the opening size required. Tapcon the front baffle into place.
Then invite the nieghbour hood around to help you move it.
Regards
Anthony
A globe have the same diameter anywhere so it can sustain a single resonance frequency at high gain... not a good idea.
In a spherical enclosure every side becomes a parallel side. Just make sure you don't excite it a frequency that will create standing waves. You'd need a pretty darn big enclosure to have a problem at subwoofer frequencies though.
Concrete is pretty good and can be poured into a mold, making it attractive in some instances. It is however not inert and can be excited to resonate just like other cabinet materials. Perhaps filling it with lead rebar or something would help dampen it. As for marble, if one is good how about a whole big bag of marbles? Put 'em in the gap with the sand.
A concrete sphere should be fairly easy to move, except on staircases. For that, a neighbour (or even two) would be useless. OTOH, an elevator would work nicely.
I've been thinking that a veneer/MDF/silicone/MDF/silicone composite would be about right for a damped, non-reflective enclosure. I suppose you could try a marble/silicone/MDF/silicone sandwich since the inner MDF/silicone layers are doing all the work.
Either would be a real hassle to fabricate. You could make entire sheets, but cutting it down would be difficult without a laser and that doesn't solve what to do at the seams.
🙂ensen.
🙂ensen.
I've been thinking that a veneer/MDF/silicone/MDF/silicone composite would be about right for a damped, non-reflective enclosure. I suppose you could try a marble/silicone/MDF/silicone sandwich since the inner MDF/silicone layers are doing all the work.
Either would be a real hassle to fabricate. You could make entire sheets, but cutting it down would be difficult without a laser and that doesn't solve what to do at the seams.
🙂ensen.
🙂ensen.
A small sphere has least diffraction.
Where does one buy lead sheets?
Would be useful for studio also.
Tom
Where does one buy lead sheets?
Would be useful for studio also.
Tom
In the US and Canada, here is a place to by lead sheets. http://www.alchemycastings.com/lead-products/sheet.htm?source=overture
I would also try plumbing specialty shops.
Dave
I would also try plumbing specialty shops.
Dave
I think the concrete layer in an MDF or wood enclosure would be best.
Enclosure walls are excited differently by different frequencys depending upon their size, structure, thickness, and materiel properties(dampening density hardness etc...)
What resonances a concrete enclosure will have a wooden one may or may not have. The idea behind the whole constrained layer dampening is that the materials resonante at different frequencies, and when one would resonate, the other layers dampen.
Concrete has low dampening, high density, and decent hardness, while wood or mdf has a bit more dampening, lower density, and the hardness varys between types. A concrete, MDF, and foam sandwich would probably be killa
Another thing I truely dont understand is why our enclosure insides dont look like anechoic chamber insides. How else can the rear wave be absorbed, resonances eliminated, and re-emitted sounds through the cone diminished.
Enclosure walls are excited differently by different frequencys depending upon their size, structure, thickness, and materiel properties(dampening density hardness etc...)
What resonances a concrete enclosure will have a wooden one may or may not have. The idea behind the whole constrained layer dampening is that the materials resonante at different frequencies, and when one would resonate, the other layers dampen.
Concrete has low dampening, high density, and decent hardness, while wood or mdf has a bit more dampening, lower density, and the hardness varys between types. A concrete, MDF, and foam sandwich would probably be killa
Another thing I truely dont understand is why our enclosure insides dont look like anechoic chamber insides. How else can the rear wave be absorbed, resonances eliminated, and re-emitted sounds through the cone diminished.
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