# new home theater - DIY



## DrPhanster (Dec 17, 2012)

Hi everyone, I've been reading posts here for a couple of years now. There's so many questions that have already been asked that I haven't often found a lot of need to ask! I am hoping for some input on my plans for my home theater room. It's entirely DIY and as this is my first house, also a little budget conscious. 

The room is 20' x 14.5' with 8.5' ceilings. ((I'd like to draw an overhead schematic, can anyone recommend something for that?)) It's in a walk-out basement, two of the walls are exterior: brick over cinderblock (1/4 of one wall under-grade). Due to incorrect construction, I'm tearing down all the drywall and have to reset all of the studs. This will give me an opportunity to treat the entire space like I want. The room is directly under the bedrooms. I'm planning on putting up polystyrene boards on the blocks, then rebuilding the studs. I'm going with 16' on center, with basic pink batts, quiet clips and channel followed by double 5/8" drywall with green glue. 

My main areas of concern are the ceiling and HVAC concerns. I'm considering drywalling in between the joists with green glue and screws, then pink quietzone batts followed by clips, channel and 5/8" drywall. 

1. Would it be safe for me to double drywall/greenglue the ceiling? 


The HVAC system is about 6 feet out, on the other side of one of the interior walls. There is currently a return on that same wall, and some rather large finished duct going through the room on the ceiling. It has two vents, one for the room in question, and one on the other side of the wall for an adjacent room. It isn't very well balanced, and very little air flows into the theater room currently.

2. I'm stuck here on how to proceed. My thoughts are, I can build soffits on both sides of the room and run flex-duct with some type of muzzle or dead vent, or I can put in an air exchange fan with an adjacent room. Since it's my first theater build, I'm not shooting for the moon, but if I can get close then why not?

Thanks so much for any help!


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## NBPk402 (Feb 21, 2012)

Welcome to the Shack. I believe a lot of people use Google Sketchup for drawing up their HT plans.


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## duder1982 (Aug 28, 2012)

I am going to install RC1

http://www.clarkdietrich.com/produc.../introduction/rc-1-pro-resilient-channel-rcur

It says you can screw up to 2 layers of 5/8 drywall on a ceiling. If you are going strait to studs or floor joist you should be fine. I am going with 2 layers of 1/2", which should be fairly dense, along with insulation.


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## Tedd (Feb 2, 2007)

I would research that RC-1 choice more.... 

Your HVAC sheet metal should have some wing nut valves to balance the HVAC.


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## blitzer (Mar 5, 2010)

> 1. Would it be safe for me to double drywall/greenglue the ceiling?


Yes, you just need to be able to support the extra weight. You can even use resilient channel as per: here. I used a drop ceiling with insulation on top of it and it was very effective, but not as nice looking as wallboard or other ceiling designs in nice theaters.


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## hjones4841 (Jan 21, 2009)

I put two layers of 5/8" sheetrock up on my HT's ceiling to help prevent bass from getting into the upstairs great room. I did not know about green glue, so I used common construction adhesive. No metal channels - just screwed to the floor joists up above. It made a noticeable reduction in LFE upstairs.

Be very careful lifting that 5/8 sheetrock - it is HEAVY. Rent the drywall lifters.


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## blitzer (Mar 5, 2010)

Insulating as much as possible above the basement ceiling will help with sound leakage and absorption of sound in both directions. Biggest bang for the buck.


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## duder1982 (Aug 28, 2012)

Tedd said:


> I would research that RC-1 choice more.... .


Is that directed towards me or the OP. If towards me, what do I need to look at. 

Thanks


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## bpape (Sep 14, 2006)

I would agree. Very easy to short out with a wrong screw placement. RSIC-V or RSIC-1 with hat channel is a better way to go and performs better too.


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## Tedd (Feb 2, 2007)

I'd add to Bryan's response to use the heavier gauge hat channel too.

edit: I should add that you want Hat Furring Channel, not resilient channel. 

That was directed to anyone considering using resilient channel.


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## ALMFamily (Oct 19, 2011)

For your ceiling - if you are willing to go to the extra effort to add drywall between the joists, it is well worth it. I did it and I had my kids stomp around after each successive layer I added (I also did two layers of drywall hung from clips / channel) and you could hear a difference each time.

As for the HVAC, if you could post up a few pics, that would be really helpful to throw a few ideas out there.

Subscribed and looking forward to following your build!


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## NBPk402 (Feb 21, 2012)

ALMFamily said:


> For your ceiling - if you are willing to go to the extra effort to add drywall between the joists, it is well worth it. I did it and I had my kids stomp around after each successive layer I added (I also did two layers of drywall hung from clips / channel) and you could hear a difference each time.
> 
> As for the HVAC, if you could post up a few pics, that would be really helpful to throw a few ideas out there.
> 
> Subscribed and looking forward to following your build!


Did you also put insulation between the joists or just dry wall?


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## ALMFamily (Oct 19, 2011)

ellisr63 said:


> Did you also put insulation between the joists or just dry wall?


Insulation too. My ceiling finishing was actually:

GG
1/4 insulation (to cover the screws that were poking through the floor above)
GG
Drywall
R19 insulation
Clips/ channel
OSB
GG
Drywall


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## NBPk402 (Feb 21, 2012)

ALMFamily said:


> Insulation too. My ceiling finishing was actually:
> 
> GG
> 1/4 insulation (to cover the screws that were poking through the floor above)
> ...


is the 1/4 insulation the foam board type? The ceiling is done before the walls are built correct (when building a room within a already constructed room)? How is the drywall held between the joists... Is it just from the GG on the insulation?


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## ALMFamily (Oct 19, 2011)

ellisr63 said:


> is the 1/4 insulation the foam board type? The ceiling is done before the walls are built correct (when building a room within a already constructed room)? How is the drywall held between the joists... Is it just from the GG on the insulation?


Yes, the 1/4 inch was a foam board type. It really serves no acoustic purpose - it was only there to give me a smooth surface.

I actually did the ceiling layer last since I knew I was doing a star ceiling and would be covering any potential issues.

As for how I held the drywall up, I cut a slew of 1' sections of 1x2s and spaced them out across the drywall. I screwed them into the joists once I had the drywall in place to avoid poking screws back in the opposite direction (up through the living room floor).


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## DrPhanster (Dec 17, 2012)

Wow, this thread took off when I wasn't looking. Thanks for the thoughts everyone, I'll get some photos up of my HVAC concerns soon.


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## DrPhanster (Dec 17, 2012)

Here's a picture of the current duct work going into the room. You can see the corner where there is a door, the duct work goes over it, and my original plan was to knock down that wall and make it into one solid room. The furnace is on the opposite wall where you see the return vent. Maybe six feet from the wall. I'm considering building soffits and running flex-duct through it. Any ideas are appreciated!


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## hjones4841 (Jan 21, 2009)

Is that the only HVAC register in the room? I am concerned about you getting enough cooling with all the HT gear on, especially if you have a projector. I have two ceiling registers a little bigger than what is in that picture and am not getting enough cooling in the room during the summer. I almost always have to use a fan in the adjacent room blowing in with the door open.

If you could pipe in a return air duct, that would make a lot of difference.


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## DrPhanster (Dec 17, 2012)

There is a vent in the corner that is a return duct. As it stands there is no sound blocking on that wall and it reverberates through the entire HVAC system. There is a picture of the other side of that wall, it shows sheet metal attached to the wall studs. That is how the return duct was vent. I'm hoping to replace it with something to kill sound a little more. The second option I'm considering is just shoving some rockwool in there and covering over it all with sheet rock and green glue.


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## bpape (Sep 14, 2006)

You'll need a supply and a return in the room. Just one or the other isn't going to do much of anything.

Consider boxing that return vent in with MDF instead of just using the cavity itself. May need to create another return cavity also. More return than supply works well in higher BTU situations like a theater.


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## ALMFamily (Oct 19, 2011)

I really feel for you guys in the South - I did not have to worry about cooling mine as it is in the basement and Wisconsin is not exactly known for its hot temps. 

It made sound isolation quite a bit simpler... That said, I like Bryan's approach.


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