I know this was around somewhere but I can't find it.
STC of Foam
Originally posted at johnlsayers.com, topic 1347.
TB,
STC specifies sound transmission, which has nothing to do with foam. Acoustic foam and fiberglass are spec'd by how well they absorb sound at various frequencies. That's completely different from how much a material blocks sound.
For a more complete explanation see the Acoustics FAQ, second in the list on my Articles page:
www.ethanwiner.com/articles.html
--Ethan
I know...there is an un-educated one over at another forum who believes egg crate will solve his sound transmission problems into other rooms...I thought I saw something that had the STC info or maybe it was the absorbtion info on egg crate. Just wanted to 'enlighten' him
Here's an actual lab test of egg crates as far as absorption is concerned - but keep in mind that Ethan's right, the isolation of ANY absorption is close to nothing, other than the improvement it can do to a total wall design.
http://www.acousticsfirst.com/docs/egg.PDF
Hope that helps... Steve
perfect, that was the point I was trying to prove...foam is mostly useless.