Wall between control and tracking rooms

chrisaiken · Post by **chrisaiken** » Sun Sep 14, 2003 8:07 am

Hi,
I'm new here...great site.I'm wondering what a decent stc would be for the wall between the control and tracking rooms?The tracking room would be for pretty much everything drums included.Ideally I'd like to be able to monitor through only monitors (not bleed).I've been reading about wall construction here and will continue to do so, but was wondering first off what I should be shooting for?How high a stc will you no longer be able to hear drums lets say?Sorry for the basic question just trying to get a handle on this all.
Thnks for you help,
Chris

knightfly · Post by **knightfly** » Sun Sep 14, 2003 9:41 am

For REALLY high isolation you'd need to give up visual communication or use CCTV cameras, neither of which is a pleasant situation to work in - even 3/4" laminated glass isn't as good as what you can do with proper wall construction, and that kind of glass is incredibly expensive. For glass to come close to wall construction, you need laminated glass, two different thicknesses that match the mass of their respective wall leaves, splayed instead of parallel, but without sacrificing air gap between the panes (means pretty thick walls overall) - I'll comment more tomorrow when I finally get a day off from work (marathon 12-hour night shifts) -

Basically, be prepared for "wallet rape" or compromise... Steve

chrisaiken · Post by **chrisaiken** » Mon Sep 15, 2003 12:25 am

I figured the glass would definitley be the weak link....thanks and I look forward to more replys.
Much appreciated,
Chris

knightfly · Post by **knightfly** » Mon Sep 15, 2003 12:41 am

Here's a site I just linked for another member - gives some realistic numbers for individual sheets, but doesn't say what to expect when two dissimilar sheets are combined in a real window.

http://www.wsdg.com/resources/resour.php?SL=te&BL=2

These guys are major players, check out the rest of their site just for grins... Steve

chrisaiken · Post by **chrisaiken** » Mon Sep 15, 2003 5:31 am

So if I understand them right ....typically you would use 3 sheets for your window?How do you think 3 double pane preframed windows would work (like normal house windows but heavy double pane)?Please correct me if I thinking about this wrong.
Thanks,
Chris

knightfly · Post by **knightfly** » Mon Sep 15, 2003 2:46 pm

From everything I've read everywhere else, that would SUCK. Multiple leaves with air space between don't work very well, in fact they usually reduce the loss compared to just two leaves. Normal double pane glass uses both panes same thickness, which is worst case for isolation of sound since both sides have the same resonant frequency therefore both sides are weak at the same frequency. Walters/Storyk kind of lost me on their triple wall thing, but note that even then they use only two glasses.

Here's a calculator demo that's kinda fun -

http://www.insul.co.nz/download.html

Not sure what the real one costs.

Eric DeSart posed a solution to glass sizing on his yahoo site that says, basically - use the same MASS of glass as your total wall layers for each leaf - glass weighs about 3 times sheet rock, so you would use 1/3 the total sheet rock thickness for glass thickness to balance out the wall. Laminated glass, since it's more limp, is better for low frequency TL.

What this means, is that (theoretically) if you had 1" total sheet rock on one side of your wall, you'd use 1/3" or 3/8" glass there - if the other leaf of the wall, perhaps on a separate frame, had a total sheet rock thickness of 1.25", (two layers of 5/8") you'd use 7/16" or 1/2" glass. You would need to NOT reverse these, or BOTH leaves of the wall would suffer... Steve

chrisaiken · Post by **chrisaiken** » Tue Sep 16, 2003 8:19 am

Ok thanks...off to do some research.
Chris