# Help with Ground Up Theater Design



## jaysant1 (Feb 1, 2010)

I'm looking for some help from some of the guys on the forum. I will be building a theater in basement. I'm looking for guidance with room size for the best acoustic performance. The maximum space than can be used is 20 x 34 but i would like to keep it much smaller maybe around 16 x 20. I'm only looking for eight seats, one riser for the back seats. The most important thing is the acoustic performance. Once i have determined the room size I can work around it for the rest of the project. Thanks for any help. 

PS ceiling is only 8 feet high.


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## Ted White (May 4, 2009)

One space-eating aspect is sound isolation. Good to have a handle on whether this is a goal or not in your room.


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## bpape (Sep 14, 2006)

With an 8' ceiling, and wanting 4 seats wide, you'd be better to go to something more like 17x21. That's what I built mine to and it works very well. That little extra width helps a lot in terms of walkways, keeping seats farther from walls, keeping main speakers farther from walls, etc. 

How concerned are you with isolation? To do that right, you'll lose a little height too.

Bryan


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## jaysant1 (Feb 1, 2010)

I'm not too concerned with isolation it's just a basement. I am going to do resilient channel and quiet rock on the ceiling. Two of the walls will be concrete and I could alway build double wall for the other two. I'm really just concernd with acoustic properties of the interior space. I will take care of isolation etc.


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## Ted White (May 4, 2009)

I understand that sound isolation is a secondary interest. I'd skip the resilient channel, however.


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## jaysant1 (Feb 1, 2010)

Ted White said:


> I understand that sound isolation is a secondary interest. I'd skip the resilient channel, however.


Suggestions?????


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## bpape (Sep 14, 2006)

RSIC-1 or RSIC-V and hat channel is a better, more predictable solution. RC is very easy to short out.

I'd recommend having 4 drywall walls in the room. The concrete outside them still isn't going to stop sound transmission out of the room. It will flank up through the gap between the stud wall and the concrete.

Also, remember that it's as or more important to stop sound getting IN to the room from a pure performance aspect. That will lower the noise floor in the room.

Bryan


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## bbieger (Sep 15, 2009)

ditto on the hat channel. Save the "quiet rock" and invest in sound isolation clips and channel. You loose about 2" of ceiling height total. Look at my thread to see how the clips were installed to minimize height loss. i.e. between joists.


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## SierraMikeBravo (Jul 1, 2007)

Hi jaysant1! Welcome to the forum!

Here is my 2 cents on the sound isolation...either go all the way or don't bother at all. You'll just waste your money and time. As Bryan eluded to, flanking via the concrete will be a serious problem. Sound isolation is about keeping the ROOM quiet. Keeping the wife from feeling 18 subs upstairs isn't the goal.

Regarding acoustics, it is better to have a bigger room than a smaller one. There are no golden numbers. Width is your friend! Length can be as well. These elelments get into the aspect of modal support and sound stage. Otherwise, we have no idea what type of speakers you intend to use or how you intend to arrange things, so it is hard to give suggestions. Work out a plan BEFORE you buy equipment. That is the best advice anyone can give regarding acoustics. If you know very little about acoustics, every room is different so I would avoid using a cookie cutter apporach by using someone elses room (it is likely it isn't setup properly anyway...I run into it allllll the time) as an example. Your room, tastes and requirements will be unique. Look into a professional to help you design it if you don't feel comfortable. You will likely find that using a professional will save you valuable time, and I can almost guarantee it will save you money in costly mistakes. Again, I see it all the time. Best wishes!


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## Ted White (May 4, 2009)

SierraMikeBravo said:


> Sound isolation is about keeping the ROOM quiet. Keeping the wife from feeling 18 subs upstairs isn't the goal.


That would be a designer's perspective. Most guys, however, are afraid of the wife.

Recessed application of clips + channel:


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## bpape (Sep 14, 2006)

You can also use something like an EXT-04 clip if you don't want to do all of the blocking up in the joists.

Bryan


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## Ted White (May 4, 2009)

Unless your joists are 16" OC and you need 24" OC channel placement


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## lkazista (Feb 1, 2010)

OK - I am confused, are you all saying that if you go through this process of green glue, and double layers of sheet rock and the channel systems and the what not, that you are only keeping noise out of the theater?

I thought that the primary (or at least a huge benefit of) goal was to keep the wife from marching down the stairs to freak out on me.

Does that make sense?

Thanks Lee


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## bpape (Sep 14, 2006)

It works both ways. It's harder in most cases to keep sound from getting out though. Not too many 100db subwoofer type things outside the theater room trying to get in 

Bryan


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## SierraMikeBravo (Jul 1, 2007)

lkazista said:


> OK - I am confused, are you all saying that if you go through this process of green glue, and double layers of sheet rock and the channel systems and the what not, that you are only keeping noise out of the theater?
> 
> I thought that the primary (or at least a huge benefit of) goal was to keep the wife from marching down the stairs to freak out on me.
> 
> ...


Hi Ikazista,

It is a benefit, but it is not the primary goal. As Bryan mentioned, pretty difficult to knock down numerous subwoofers from leaking out of room that have walls only 4-6 inches thick considering the wavelengths are significantly larger. The point is, if you don't do it correctly by dealing with the floor, the door and assembling the room, then you have wasted a lot of time and money. DD, GG and whisper clips are not all that goes into isolating a room. Best wishes!


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## bbieger (Sep 15, 2009)

I would say the "primary" function of sound proofing is user dependant. Any soundproofing that keeps sound out is also keeping it in. My new sub shakes the entire frame of my house but without the soundproofing I did it would be an order of magnitude worse. I rarely watch movies at a volume that I can hear footsteps upstairs so the only external sound I was attempting to keep out was that of my wife coming downstairs to tell me to turn the volume down. 
_Posted via Mobile Device_


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