[Nick77]

We are planning a build this summer and have some real basic questions.
I want to treat a game room/media room to contain noise as well as acoustic benifits.
I bought a case of green glue and plan on treating the 2 interior walls with double layer drywall and either blown cellose or cotton insulation.
#1. Does treating the room with GG and double rock provide any acoustical benifit or strickly containment? Should I consider treating the 2 external walls with GG and double rock?
#2 Would stagering the studs on the interior walls do the same thing as channeling? I think the main wall is 6" due to the fireplace on oposite wall and believe staggering studs should be no problem.

I do plan on some wall mounted acoustic treatments but didnt know if treating walls were of any benifit besides containment. Thanks

[Nick77]

Burrrrrrr its chilly in here. Did I ask for advise innappropriately?

[MaxCast]

Ok, I'll take a stab.  I redid a basement and isolation was very important to me.  Yours sounds like a first floor room.  Since this is a new build I am going to assume you can do whatever you want.  Where you can't we'll have to do the best we can.  I'm not sure how fancy you want to get or the budget.

First, big rooms and high ceilings are great.  Search for the better room dimension ratios and apply as best you can.

Second, the best construction for sound isolation is a room within a room where sound is not transferred by physical contact between floors, studs, joists, etc.  Flanking noise is important and easier to tackle when you are building new.   Are there any living quarters above or below this room?
Staggering the studs with insulation in the walls is good.  Double dry wall with GG is good.  Boxing outlets and light fixtures is good.  I believe GG has acoustic and isolation properties.  Caulking all seems and holes is good.  Think of it as fish tank.  No leaks.  Use a solid wood exterior door.

Lost of good advise in other threads in this circle as well.

[bpape]

Sorry - missed your post yesterday

Green Glue is useful at isolation both ways.  It'll help keep sound from getting out AND more importantly, help minimize sound getting into the room and raising your noise floor - degrading the dynamic range potential

Using double drywall and Green Glue on only 2 walls isn't really a good way to go.  The sound will still flank around to the weakest point in the othere walls and the ceiling.

Staggered stud construction can be very helpful in stopping transmission into the room on the other side of that particular wall.  To provide isolation to other areas including above, you want to isolate the entire frame from the rest using isolation clips.

Bryan

[Nick77]

Sorry - missed your post yesterday

Green Glue is useful at isolation both ways.  It'll help keep sound from getting out AND more importantly, help minimize sound getting into the room and raising your noise floor - degrading the dynamic range potential

Using double drywall and Green Glue on only 2 walls isn't really a good way to go.  The sound will still flank around to the weakest point in the othere walls and the ceiling.

Staggered stud construction can be very helpful in stopping transmission into the room on the other side of that particular wall.  To provide isolation to other areas including above, you want to isolate the entire frame from the rest using isolation clips.

Bryan

Thanks for the responses.

Bryan so if i am considering double rock and GG i should do all 4 walls to achieve best results? I am only looking for isolation for the 2 opposing walls connected to hallway and greatroom but if I will have a more dead sounding room before acoustic treatments then i guess it would be well worth it. I guess i could just imploy the staggered studs on the two opposing walls for increased transfer isolation. Room size is 14'x18'.

The house is new construction single story on slab and the game room will have 10' flat ceiling next to the great room with approx 16' ceiling and vaulted. Point being i think the two roofs are independant of one another. I was thinking the 24" or so blown cellose will more than take care of the ceiling worries??

Am definately considering solid doors, but i hadnt been considering double rock on the other two walls. I dont know what effect double rock has on doors and windows for new construction. i will have to ask the builder, do you order special doors and windows or trim is just done differently?

thanks for your help.

[bpape]

While the ceiling may be different structurally, the airspace may be shared.  If it is, you'll get noise transmission.  Also, consider any holes like electrical outlets, can lights, light switches, etc. as those will all defeat isolation.  Just boxing around them will work.  You'll also need to look at HVAC connections and boxing some of it in to avoid transmission via that.

The additional drywall thickness will require that you use adjustable outlet/switch boxes to compensate. 

If the 2 other walls are exterior walls directly, then you're still having connections to the rest of the home for sound to move through the structure.  You can help this by disconnecting the walls from each other. 

For the doors, solid core wood doors are the most cost effective solution. Acoustical doors are horribly expensive.  The additional thickness here will require a thicker jamb.

Bryan

[Nick77]

thanks for the help, attached is a copy of plan. still wonder about window wall needing double rock?
Just for the record there is no shared air space for ceiling, GR has only 12" or so ceiling/roof.
I will be sure to discuss desires with hvac guys.
I guess if i have the framers do a six inch wall across back and side with stagged studs it might be ideal? Thanks again.

[orthobiz]

I need to post some pics of my room construction, I'll try to do it in a day or two.

My 12x17 basement room was done with double drywall 5/8", green glue and staggered studs. I did not do isolation channel but I did buy some fireproof sheets that go behind the electrical outlets and wall lighting sconces to try to keep the sound in. It's a solid core door with a sash and seal (outside style door) but it's not made of wood. No cans/recessed lights in the ceiling. I wove R13 between the studs.

The outside wall (in the family room) is 1/2" drywall, no special treatment.

The sound isolation inside and out is terrific. I can listen loudly without disturbing the kids who can easily watch TV, no problem.

The drywall people only wound up using one tube of GG per 4/8 sheet instead of two. They felt it was too runny but they were trying to zigzag it on the sheets held vertically and the nailing it up as quickly as they could. The GG people recommend holding the sheet horizontally, putting the GG on and then nailing it up super quick. They had the instruction sheets right there (complete with LOTS of pictures).

Just goes to show that no matter how carefully you plan, you GOTTA stay on top of it every minute.

BTW, I have two cases of GG I wanna dump so PM me if you're interested in a good deal.

Paul

[JLM]

IMO you only need double/staggered stud walls on adjoining walls.  I used insulated/lined flexible duct to my room and it worked great.  I'd try to replace the double door with a single insulated exterior fiberglass door.  The weather seal works miracles in my room, it was spooky quiet (but I got over the feeling of isolation). 

Double drywall stiffens the walls, but so would spacing the studs closer together (12 inch spacing versus 16 inches). 

Try to have dedicated circuit(s) for the A/V equipment (a great "while you're at it" feature).

Unforturnately the room is not in ideal proportions and it does have windows, but having a well insulated/dedicated decent sized room will be huge and puts you ahead for most audiophiles.  Have fun.

[orthobiz]

Yeah, what he said! Do everything JLM says. I did and I'm really, really happy.

Paul

[Nick77]

IMO you only need double/staggered stud walls on adjoining walls.  I used insulated/lined flexible duct to my room and it worked great.  I'd try to replace the double door with a single insulated exterior fiberglass door.  The weather seal works miracles in my room, it was spooky quiet (but I got over the feeling of isolation). 

Double drywall stiffens the walls, but so would spacing the studs closer together (12 inch spacing versus 16 inches). 

Try to have dedicated circuit(s) for the A/V equipment (a great "while you're at it" feature).

Unforturnately the room is not in ideal proportions and it does have windows, but having a well insulated/dedicated decent sized room will be huge and puts you ahead for most audiophiles.  Have fun.

Thanks for the input. Is the duct you mention a common hvac product? I will be sure to mention that to the hvac guy.
I wasn't to crazy about exterior walls being staggered so I appreciate your input.
I am seriously reconsidering the double doors so that all is not in vein. Is fiberglass a commom product?
I was thinking 14x18 was not too far from ideal but doesn't matter but the question still remains what is ideal room size?

In reference to dedicated electric with common number of av items (tv, sat, receiver, 2 amps, dac, dvd ect) what would be your recommendation? 2 lines supporting 4 plugs? 8 plugs? or is one line supporting 4 plugs ok?
Lastly is 1 1/2 GG tubes per sheet of rock an ideal target?
Thanks for your help

[laserman]

Nick77,

Some great ideas posted.  My only addition would be for you to read two more threads - "The Perfect Room," here in The Acoustics Circle tab and "Wow! What a Sweet Audio Room" in the Audio Central Tab.  I like the SRA room with the corners filled in and the center convexed diffussor (I know you are going to have to make some calculations to get the arch alligned with the size of your room).   Since it appears you have a relatively clean canvass to work from...doing it right from the get go will net you great results. I wish I had the same opportunity.

L

[orthobiz]

A few pics: my staggered stud wall, every 16" each side, so it looks like every 8".



The doorway. My contractor started to get into the isolation concept and made a separation between the thinner area where the door actually hangs and the thick outer area where there is extra molding.


R13 weave from outside

Combo shot: weave seen from the inside on the left. Straight runs of insulation on the right: it's the outside of the house and is underground. No double wall here!

More weaving.

Finished room:
http://www.audiocircle.com/index.php?topic=63893.0

Hope this helps.

Paul

[Nick77]

Awesome post! Thanks for sharing. Love your Cave!