daav
Flailing up a storm.
OK so i found a place in VT that sells Johns Manville insulation (no one i called seemed willing to help much with OC 703 at all). One thing i can say is when dealing with local suppliers, to try to not mention the noise reduction aspects of the stuff, it seems to confuse things if they don't know it for these uses already.
So anyway, i am going to run over and check it out today, and had some last minute clarifications i wanted to make:
They didn;t seem to be aware of the "800 series" that i have seen posted about, has anyone esle bought this stuff that they can help define the model i should be looking for?
Similiarly, if i am looking for a certian density/cubic foot, and am dealing with fiberglass "board" will i have pretty good luck getting good noise reduction if i have to wing it? i.e. if it looks like rigid and walks like rigid, will i have a good shot?
Is mineral wool all pretty much the same stuff? I have seen good noise reduction there.
last, has anyone had to buy the foil or paper backed rigid? if that is all I have available is it possible or reasonable to remove the backing to improve the noise reduction?
PS i have read a ton on this, but info is all over the place, i want to be armed well when i go browsing today. I will update the "where to find" thread when i can verify that they have the good stuff for the 4 VT people on the boards.
Daav
So anyway, i am going to run over and check it out today, and had some last minute clarifications i wanted to make:
They didn;t seem to be aware of the "800 series" that i have seen posted about, has anyone esle bought this stuff that they can help define the model i should be looking for?
Similiarly, if i am looking for a certian density/cubic foot, and am dealing with fiberglass "board" will i have pretty good luck getting good noise reduction if i have to wing it? i.e. if it looks like rigid and walks like rigid, will i have a good shot?
Is mineral wool all pretty much the same stuff? I have seen good noise reduction there.
last, has anyone had to buy the foil or paper backed rigid? if that is all I have available is it possible or reasonable to remove the backing to improve the noise reduction?
PS i have read a ton on this, but info is all over the place, i want to be armed well when i go browsing today. I will update the "where to find" thread when i can verify that they have the good stuff for the 4 VT people on the boards.
Daav
Could you describe exactly the design of these "tubes", and by what principle they become low frequency absorbers, or where the design came from. I'd be interested in seeing this. And what do you mean by "airtight". Resistance absorption needs an exposed surface to the air in order to work at optimum. Yes, batt type insulation will absorb within a wall, but that is because of transmission of vibration into the airgap, which is .....well, filled with insulation. Membrane absorbers work by resistance to resonance vibration, which transforms mechanical energy into heat. TUBE TRAPS, which is a proprietary design whereby a wire frame is formed into a tube, and fiberglass or other absorption material is inserted on ONE HALF the tube, with a reflective face to the outside. When placed in a corner, the reflection from the corner is theoretically aborbed by the fiberglass facing the corner. This is actually broadband resistance absorption as the fiberlass is no more than an 1" thick. However, how do you make a tube shape made of wire, and exposed to the air, "airtight"? 
Thats preposterous. Thats why I asked how your "tubes" are constructed, and by what principle they become absorbers at low frequencies.
Now, I TRY to limit my suggestions to what I have researched to the point of satisfaction with its integrety. Still, I also try to include this DISCLAIMER usually. I AM NO EXPERT!!
But if its wrong, I know I'll hear about it. The real data on acoustics and isolation can be found if you know where to look. One of the best sites around for truth in these matters is here...