# Stud wall screen Isolation(low freq)



## Lunchietey (Jul 11, 2012)

Hi guys, 

I'm very close to starting the construction of the stud walls which will split my l-shaped room in half to make a cinema and a bedroom/study.

The house is concrete floor, brick/plaster walls and is very solid and quiet. What I'd like to know is the best way to isolate low frequency sounds through a stud wall? I know I cant stop it all, but I'd like to be able to watch a movie at a comfortable level without disturbing too many people(or have kids watch a film without driving me nuts haha)

I've read the best kind of stud wall has two essentially independent stud walls, not touching each other(no common studs between opposing faces) the wall thickness is not a real issue. So fixed top and bottom rails(6"), and two staggered sets of 2" x 3" studs so the plaster/mdf panels of bothe sides of the wall dont touch and can vibrate a little absorbing the sound. fibreglass/rockwool batts obvioulsy get installed in between.

The screen wall which I'm building will have the speakers built in, and i'm thinking the rear of that wall(which will fill a square opening/archway) will be 13mm plasterboard over 19mm ply, air gap(or foam/batts) then 19mm mdf(rear of speaker enclosures) then mdf front panels behind screen. The plaster wall in the hall will not be mechanically coupled to the rear of the screen/speaker enclosures.

Speakers for LCR will be 12" bass driver or dual 8's(high fs/high efficiency low q-not a prosound driver but not a sub 80hz up) and a 6" fostex ff165wk crossed at 500hz to mimic x-over point in pro cinema applications, and giving the fostx good spl potential.

Also, is lining the ceiling a good idea? I'm worried bass will simply go through the roof 10mm ceiling plaster into the roof space, and venture into the next room. Could a layer of 3/4 ply over all of the battens above the cinema(basically like a floor in my roof over the beams/battens/insulation help? The lights in the theatre are all going to be led 12v, so heat shouldnt be a problem.

Thanks again


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## bpape (Sep 14, 2006)

For walls that are shared on the same level, yes, staggered stud can work pretty well. You might also consider DC-04 clips to further isolate the wall by decoupling the top plate from the shared ceiling structure. 

Any and all walls/ceiling need to be isolated or you're correct and it will flank via any shared adjoining space, like the attic. On the ceiling, you would want to do RSIC-1 or RSIC-V clips and hat channel to decouple from the shared joist space. Insulate and double drywall all walls/ceiling with green glue between drywall layers.

Bryan


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## ALMFamily (Oct 19, 2011)

There is a ton of good information / advice on this site - I ended up going with Whisperclips myself:

http://www.soundproofingcompany.com/


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## bpape (Sep 14, 2006)

Yes - the Whisper Clip equivalent of the products I referenced will work very wall also.

Bryan


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