From: Jon Best <jrbest@x???xx.xxxx
Date: Wed Dec 8, 1999 2:11 pm
Subject: STC and others
> > Doesn't 'less stiff = more likely to absorb low end' also kind of mean
> > stiff= more likely to transfer low end through the wall?'
> Yes I would think so .... but only to the extent the two walls are coupled
> (either mechanically, or through the vibration of the cavity's air mass.
> Given double studs, interior fiberglass batts, and the fairly high mass per
> SF of the two wall coverings, I'd think that the two sides would be largly
> independant (low transference).
> Dan makes an interesting point about making the cells defined by the studs
> different sizes by installing horizontal members to break the cells up into
> different sizes, so that such interior air mass vibration that does occurs
> will be spread across differing freq.s ... this seems rational, but I wonder
> how much difference it would make in the system's STC vs. the trouble
I'm not sure how much good this would do in a staggered stud wall, as there
aren't really any isolated cavities- it's all one big air pocket.
> What is your target STC?
Kind of funny- my target STC is "as much as possible," just because it makes
sense to build as tight as I can in the beginning. I'm not going crazy,
because I've got three neighbors I can see, and only one I can hit with a rock.
They've been OK with my band practicing in the original part of the building,
with 24" OC 2x4 walls with 1/2" ply on one side and 1/4" lauan on the other.
You can have a conversation through it. That's the next room to get some
> I bet the system you have designed is already pushing 65
> FWIW here's a nutty one. Rip the material to 6" and hang it between the
> studs as free floating interior panel absorbers
Hm. I am inclined to do weird stuff, but I'm not sure about this one.... :)
> Scott R. Foster
Sales Weasel From Mars