# Forum Home Renovation Home Theatres  Sound proofing for Theatres.

## Rod Dyson

Hi,
I you need to sound proof a room like a theatre etc. you may be interested in comparing the acoustic peformance of various plasterboard types, see the cost vs benefit.  
We have added a new page in the tips section of our website to assist people choose a sound sytem that is cost effective.   
Cheers Rod Dyson

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## sco

Anyone doing a DIY home theatre should spend some time reading the Room Construction forum at "www.avsforum.com". Lots of handy tips on building a screen in the Screen forum there too. Built mine for $70 in an afternoon  :Smilie:   
For sound proofing I used 16mm firecheck + 10mm standard board on all walls and ceiling with insulation between the studs to reduce reverberation. Density is your friend when it comes to stopping sound and that firecheck weights a ton.  
Not perfect but the best I could do given I didn't have the room for acoustic isolation using 2 stud walls. I can watch a movie at normal volumes and not be heard upstairs in an old Queenslander, which doesn't stop sound very well. If I turn the wick up it can be heard (especially the bass) but not enough to upset the neighbours. So that was mission accomplshed. 
Cheers 
sco  *Edited Post :*  Removed cross-forum link

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## Rod Dyson

You are right there, Density is your friend and his mates are Isolation and absorbtion.  You have the absorbtion in the insulation, isolation is preventing sound trasmission through direct contact of lining material. 
Building a second frame is one method, of isolation, or using isolation clips and 16mm furring channel.  
If you are looking at reducing sound in a gerneral sense use plasterboard that has the best density, check not only the price of the materials but the weight per m2.  The heavier the board the better the acoustic performance.   
Cheers Rod Dyson

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## Ecobuild

Hey guys, 
we use the Durra panels as ou first layer, due to the density of the product. Awesome oise insulation and 100% eco friendly. It's just compressed straw. The panels are 50mm thick and solid. In fact they are s solid you don't need a frame if under 2700mm high.
For added acoustic control we the install Gyprock EC08 impact board. Similar to the fyrecheck board, but better acoustics, and approved by GECA. Both of these products ae also listed on the ecosupplier website. 
We use the same system for our recordng studios, except we build a double layered wall. 
At the end of service life the Durra panels can be chopped up and used for mulch  :brava:

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## Ted White

Mass is really the key, so whatever is heavier after all layers are added. Hopefully the mass is decoupled from the framing and damped.

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## ndaki

how about windows and the type / thickness of panes?

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## Ted White

You're referring to laminated glass? Thicker = more massive = better. The lamination helps damp vibration, however having the glass panels of dis-similar thickness is still a good idea.

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## GraemeCook

> how about windows and the type / thickness of panes?

  Double glazing or secondary glazing is best, by far. For accoustic insulation the greater the distance between the panes the better. 
Cheers 
Graeme

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## Elill

Gees Ted, you get around  :Smilie:  nice to see you popping into an Aussie forum! 
I suggest you look at Ted's excellent website on the topic soundproofingcompany.com 
Go the the articles section

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## Ted White

Hello Elill!

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## Moondog55

Green Glue for doing constrained layer plaster is now available in Australia, I have not tried it myself yet but on "DIY Audio" forum it is regarded as one of the best ways to soundproof when retro fitting and you do not want to remove the original wall

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## LS1BEN

Not just mass but also as many different types of materials in the room will stop different frequencies getting out..  I built mine myself underneath an old highest wooden home I had at the time and after a lot of research did this    10mm cement type cladding on the outside to match the house then 90mm timber frame with r3.5 insulation and 10mm normal gyprock then about a 30-40mm gap then a 64mm (or 66mm, cant remember??) Steel studded wall with rockwool insulation (the best!) then 10mm Sound check. Also every single spot that 2 materials touched had and any tiny air gaps had caulk put on it. Also used a river rock paint (textured) on the walls and thick underlay and carpet..  Because I was already under legal height I couldnt do as much as I would have liked with the roof and just glued rubber strips to the joists before screwing in the 13mm fire check to dampen the vibration that was going to come through to up stairs.   Also then just solid core doors and rubber strips around them. No windows, just air con.  I could crank a 15k setup in there pretty much as loud as my ears could take and during a normal day you wouldnt hear it if you were walking past.   I can post pics if anyone is interested.  Cheers.

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## Ted White

Sounds like a heroic amount of work. As a rule of thumb, if you had a choice, you would only want one air cavity in a wall or ceiling. Two or more air cavities will each have resonance that will reduce isolation. The Significance of Air Cavity Depth & the Triple Leaf Effect | Soundproofing Company

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## Moondog55

Just read thru it; not as effective as staggered stud walls; but most of these need to be designed from the ground up.

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## Ted White

Read through what, the linked article or this thread?

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## Moondog55

I read both the linked thread and this article.
It is an interesting subject; even if we will never have the spare funds to build our own home theater' some of the techniques are applicable to cutting down exterior noise when building from scratch.

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## Ted White

I really think the topic is interesting. Especially interesting.for people that understand construction, I find.

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## Moondog55

I think the staggered stud construction would be worthwhile using as the exterior walls when building our next home, the extra 50mm of thickness allows a lot of extra insulation, the downside is the extra cost of the 150mm top and bottom plates and 50% more studs and of course 50% more Rockwool

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## Ted White

Here in the states anyway, we can spread the studs from 16" to 24" to save on studs.  
Also, you would want to consider the notion of leaving the insulation the same as in a common single stud wall, unless needed for thermal reasons. Adding more would be a very poor acoustic return on investment.  
R13 fiberglass or rockwool. Installed vertically, not horizontally (woven). Weaving can pinch the insulation and you can measure the conduction that this pinch allows.

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## Moondog55

Ted you must measure R value differently in the USA, here R13 would be about 500mm thick. 
I don't think our building regs have come to terms with staggered stud construction yet, I asked my builder cousin and he had never heard of it

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## Ted White

Wow! I guess so.... Here R13 is 90mm

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## Moondog55

Decimal point then, R1.3 in OZ is 90mm.

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## Ted White

That's a nice tidbit to know, Moon. Thank you for that.

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