Trying to grasp isolation concepts

[Executivos]

OK, so I've done some more research and it looks like we're going to run with the wood shed idea. Keep in mind this isn't so much for recording, but just simply for rehearsal, and just need to not bother neighbors.

These sheds are built pretty well, 2x4 framing, with 3/4" plywood walls, and the room will either be 12x16 or 14x18. We're going to build a room within the room and floating the floor and I'm trying to estimate the costs. I've done a lot of research and everyone seems to have a different opinion.

Inside the shed as it comes, you can still see the frame....it's basically a 2x4 frame and the exterior plywood is mounted but the interrior is not covered.

So from there I would build an entire seperate frame with neoprene pads under the studs for the new walls. What to cover with and were to put it is where i'm confused. They sell "sound deadening" board at home depot by me and it's relatively cheap...I was thinking the attached picture would be the best way. If someone could tell me how much airspace to leave between the two walls and also should the sound deadening board be on the other side of the frame or maybe attached to the outer wall and should that be attached to the channeling as well or just screwed or nailed in.

As you'll see in the picture, I was thinking:
There's the exterior wall which is pretty much just 3/4" plywood and a 2x4 frame.

there would be an airspace of 4"?? (is that enough?)

the a layer of sound deadening board attached to the second frame (mounted on pads)

insulation inside the framing

Resilient channel

Drywall

I'm sorry if my terminology is incorrect, Im kinda new to this.

Yes I have people that know about construction, just not studio construction that are helping me.

 

[Executivos]

sorry forgot to attach the picture

 

[longsoughtfor]

Exec - you might consider building your wall as suggested on the SAE website (see pic.).

The main difference is that the interior wall is not covered with sheetrock but rather slot resonators, fabric covered rigid insulation or just fabric. The advantage is the ability to control the amount of sound energy inside the room as well as what gets out.

Also, in a rectangular shed, consider making at least one of the long walls non-parallel to the other.

Cheers
Kevin.

 

[longsoughtfor]

... Since I only grabbed the picture and not the explanation from the SAE web site, John's wall design is the one on the left.

My appologies
Kevin.

 

[John Sayers]

Executivos - in your situ I would cover the inside wall of your shed with sheetrock on a resilient channel. That will reduce the sound going from your inside layer, thru the studs , to the outer plywood layer. Some insulation in the cavity would also help.

Then build your inner frames on the floor, sheetrock them, then attach insulation and then stand them up so the insulation goes against the channeled sheetrock. 2" airspace so you don't loose all your rehearsal space. Then you will have what you started with except with two layers of sheet rock and insulation between you and your neighbours. BTW I'd use 3" x 2"s for the inner wall.

This type of construction is shown in the studio Left Bank at

http://locall.dataline.net.au/~johnsay/Studio/index.htm

get your builder to take a look at it.

cheers
John

 

[longsoughtfor]

John - So, what would you do in a 12x16 room with 4 sheetrock walls to control modes etc?

Kevin.

 

[Executivos]

Okay I think I understand.....

So There's the outer plywood/frame with insulation inside, then resilient channeling and 5/8 Sheet rock (drywall right?)

Then come in 2 inches, another layer of insulation, the inner frame with drywall attached to that without resilient channeling.


#1 is that sound deadening board not worth it? I though it might be better than the sheetrock.

#2 does the inner wall need to have sheet rock on both sides or just the side we'll actually see?

#3 Why is is 2x3's better than 2x4s in the wall framing

I looked at the site...(been there many times, but I couldn't make much sense of most of the pdfs on there. Is there a spefic one I'm completely missing?

One more question. We're trying to figure out how to get air conditioning in. Remember, it's not for recording, so If you can hear the air conditioning INSIDE, it doesn't matter. We just dont want sound to leak out through it. Any Ideas?

 

[Executivos]

oh yeah once again I forgot the picture....is this what you mean?


Also is that 2" of airspace meaning from outer frame to inner frame?

 

[ausrock]

Exec,
I interpreted John's suggestion as being;

Outer cladding (existing)
Stud frame (existing)
Insulation between studs (new)
Resilient channel (new)
Sheetrock (new)
2" Air gap filled with insulation
Drywall (new)
Stud frame (new).

 

[John Sayers]

That's it ausrock - why 3x2 cos it's cheaper and the walls aren't holding up the world, so they don't need to be goliath

cheers
John

 

[longsoughtfor]

Not too far off topic...

For the inner wall (the 2x3's) can you place the studs on 24" centers vs 16" ? Is there any STC difference?

Kevin.

 

[Executivos]

Exec,
I interpreted John's suggestion as being;

Outer cladding (existing)
Stud frame (existing)
Insulation between studs (new)
Resilient channel (new)
Sheetrock (new)
2" Air gap filled with insulation
Drywall (new)
Stud frame (new).

Ok that's cool. I got a few questions though

what is sheet rock? I thought it was the same thing as drywall.

If I follow that wall plan then doesn't that leave me looking at studs?? what covers up the wall on the inside of the room?

I called home depot and their price on 2x3's was 1.99 Their price on 2x4's was 1.99 Is there any other benefit to the 2x3's than price?

Ok sorry one more question....How about the ceilings? I've seen a lot of different variations on construction methods. Can somone give me the best idea in a layer by layer method? You have no idea how much I appreciate it.

 

[Executivos]

OK through some further investigation on the studio contruction site i came across this attached picture. So the only thing I should change is more insulation inside the outer frame as well.

Oh yeah and can someone tell me where to buy neoprene padding and resilient channeling in the US

 

[John Sayers]

Yes you will end up looking at the studs but you now have a cavity for internal acoustic treatment. Otherwise you will end up with a plaster walled room which will need treatment that will takeup extra wall space. The advantage of my system is that you won't loose anymore room space to do this.

You can now put insulation (rigid fibreglass or similar) in the cavity and covered with cloth for high frequency absorption, or you can put slots over the cavity for low-mid absorption, or plywood panels for low frequency absorption PLUS you have not lost any more room space.

check out Left Bank at Studios Under Construction where this technique was used.

cheers
John

 

[Executivos]

oh okay that makes sense....I saw the slat resonators...I just didn't quite "get it" until now.

Keeping in mind that this is mainly a practice space, what would be the best orientation of them?

(There's 4 walls, 12x16, I'd assume not ALL slat resonators, and not ALL just cloth)

we're thinking the drums will go along the back of the 12 foot shorter wall. Would the slat resonators be best behing the drums etc etc?

Thanks again....

 

[longsoughtfor]

John, How do deal with wiring in the "inside-out" wall approach? I'm wondering about AC wiring primarily.

Thanks
Kevin.

 

[Alex W]

Exec,

If you have't tracked it down yet, resilient channel is available from Dietrich Metal Framing. For So Cal, you can call their plant in Colton to find a distributor in your area (909/824-9717). In San Diego its distributed by a company called AMS and they quoted me a cost of $1.43 per 12-ft length.

I don't know about garden-variety neoprene but there's a company here in Vista that sells acoustical building materials and I think I remember seeing some type of underlayment on their site -- soundproofing.org.

Alex

 

[Executivos]

yeah I found it out here. I think it was 1.50 for 12' and then another place had it for 1.16 for 12'

Maybe somebody can help me with this...They said that had rc1 and rc2, and the rc1 was usually used for walls and rc2 for cielings. Then one place told me I could use furring channel or something like that??

What is the difference between the 3?

I got in touch with soundproofing.org, I think I'm going to buy the neoprene from them...They are just about the only place I called that even knew what I was talking about.

One more question, with regards to installing the new floating floor. (BTW, we're not using the prebuilt shed, we hired a contractor to build a whole new room (now 14'x18') He's just doing the outer structure and leaving the inside walls empty, and we are doing the inner room and insulation etc )

Anyway the existing floor, (he's building right now) is pressure treated 2x4's with 3/4 inch plywood on top. Then were are going to put neoprene pads down, another 2x4 frame, insulation and another 3/4" ply layer ontop of that. With regards to actually putting it down, should we use long screws going through all layers to the sub floor (even going through the neoprene) or would that destroy the whole floating floor concept? Basically I'm just trying to find out if the new floor (and walls and false ceiling) are supposed to be attached the the old floor or just resting on it.