STC and others

[archive]

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
> 'less
> > 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
> involved.

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
attention....

> 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

Jon Best
Sales Weasel From Mars

[archive]

From: SRF7@x??x.xxx
Date: Wed Dec 8, 1999 11:48 pm
Subject: Re: STC and others

In a message dated 12/8/99 9:11:12 AM Eastern Standard Time, jrbest@e...
writes:

> From: Jon Best <jrbest@e...>
>
> 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.

snip

They still have modes and can be viewed as cells even if open ended (just
like the studio still has modes even if you leave the door open). It'd be
the height mode that horizontal members would cause variance in ... and
variance in this mode would be induced regardless of whether single stud or
staggered stud construction was employed.

> > 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.

snip

More mass ... lots of caulk.

Scott R. Foster