Sin x/x wrote on Fri, 13 October 2006 01:35 |
Foam is a not such a smart way to eliminate acoustic problems.
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Whoa . . . careful there. We're talking about tools, here. Would you use a screwdriver for a hammer?
Foam is a
great acoustic absorber when you use enough of it in a given application. There's nothing better, really. (I'm including fiberglass, rock wool, faded blue jeans and whatever other flavor of the day is available for absorbing sound under the descriptor "foam".)
Do you need a
lot of foam to achieve near-unity absorption down in the lowest octaves? Well, yes. In most situations, there comes a point where broadband bass-trapping probably represents a better use of space.
But too many people over-simplify the activity of foam and get wrapped up in "thickness" and "wavelength". Sound doesn't just hit walls in a perpindicular fashion. For an oblique or near-tangential angle of incidence, the dimension of interest isn't the thickness . . . it's the
width (or height) of foam. Think about that and you might get a better feel for why a nominal thickness of foam can actually absorb some fairly low-frequency sound.