John Sayers' Recording Studio Design Forum Archive

We are planning on building out a garage into a practice space/tracking room. We have a separate location that we mix at, so we have no need of control room, iso booths, ect. Just a big open room to practice and record in. We will have gobos and such to help partition some of the space. We mostly record rock bands; 2 guitars (half stacks + 100 watt heads), bass(8x10), drums. For rehearsal, add a PA. Also when considering HVAC, this is Minnesota and, for those who don't know, that means 30 below in the winter and 90+ in the summer. We want air conditioning, but I'm guessing that it will be sealed enough to stay warm in the winter.

Description:

Photos...

http://www.tc.umn.edu/~kayse007/garage/index.htm

Top of beams to floor 8.5'
peak of roof 14+'
Width 21+'
depth 25+'
stud depth 3.5'
must keep garage door

Requirements
Have reasonable sound abatement - the nearest house is 40 feet way, but it is a residential neighborhood that is fairly quiet (i.e. not a busy street)
Worthless if it pisses off neighbors.
Must sound fairly good in the room - low reverb time, not too dead,
near worthless if it sounds horrible to track in( I guess we could still practice there).

WANTS
decent air flow
highest ceilings possible


Initially I thought that we should do this
1) apply one or two sheets of concrete board in-between the studs
2) Caulk
3) an inch or so of rockwool
4) concrete board
5) more rockwool to total stud depth
6) double drywall
7) caulk
Do this all the way up to the peak, so all walls and ceiling. Also build a wall in front of the garage door and do this to that wall.
Then build an inside room, but use 703 in those walls/ceiling and maybe not even dry wall all of those walls.

My thinking here is that the outside walls would be dense and have varying density. I was hoping (maybe too much blind optimism) that those outside walls would be thick (about 4 inches) enough to stop much of the sound and that having an inside room that was all 703 would kill most of the sounds reverb time.

BUT, then I read other message boards and now what I think the collective thought would suggest our plan be is...

1) caulk the gaps in the garage shell.
2) Fill in between the studs with pink insulation(read somewhere on that it is as good as rock wool in this application, which doesn't make much sense to me...)
3) Leave this open faced (again I read that somewhere)
4) Frame a new wall (how big of a gap should be left between the leaves?)
5) Fill this wall with pink stuff (again, would think 703 or rockwool would be better, but I guess not)
6) Finish the wall with double drywall(is RC worth it if we are trying to not piss off our neighbors? I read that without RC you get better bass stoppage and bass is usually what carries)
7) caulk
8) surface mount the power outlets

We have questions about the ceiling/roof
How do we (and is it worth it?) raise the joists?
Is there a way that we can use the height in the garage to our advantage? It is a large volume of air. Will it help us the leave it open? Fill it will insulation?



Questions

What plan is going to give us the better stoppage of sound (those neighbors...)?
Should we 'splay' the walls?
What should we do with the floor, it is concrete (see photo)?
how big of a gap should be left between the leaves?
Is there a way to build bass trapping into the construction - kill two birds with one stone...?
What about diffusion?
How to raise the joists - is it worth it.
HVAC? - bathroom type fans?
How can we use/keep the height in the final room

Budget
around 2000-3000 - more if we feel it is worth it. For example, we can live with less than ideal HVAC if the next step up is $1000 more, but would toss in extra man hours and $$$ to keep/add some height in the room.
no labor costs - we have a group that will help build in exchange for studio time.

Comparisons
This band built a practice space in their garage. I've emailed them and they say that at 30 feet you can't tell a band is playing in there. That is great, but I would imagine this room to be uncomfortable to be in and they even say that they wish there was air flow. Plus they basically have NO trapping/diffusion.
I'm thinking of these guys as a 'base line' if I can get as much abatement as them I would be happy.

http://www.platesix.org/garage.asp



J.Hall build bass trapping in his walls. Could we do something like this?

http://recforums.prosoundweb.com/index.php/m/0/83/0/0


This guy gave me the idea for the unfaced inside walls

http://www.dougyoungguitar.com/step1.htm



Thanks a ton to all who respond!

I anxiously await everyones thoughts,
mark

Hello and welcome to the forum.

First off, your initial thought:

Initially I thought that we should do this
1) apply one or two sheets of concrete board in-between the studs
2) Caulk
3) an inch or so of rockwool
4) concrete board
5) more rockwool to total stud depth
6) double drywall
7) caulk

This is a 3 leaf system. The second one you posted is better. As far as insulation, use 2.5 - 3 lb mineral/rock wool or 703. (mineral wool is more affordable).

Check the "complete section" sticky at the top of the forum. There's some good info here. Also, do a search for other garage setups. There is a lot of other good info and some of the same questions have been answered that may or may not work in your situation.




Aaron

what about 'fortifing' the outside wall first with a layer of cement board? Isn't that sort of like double drywall?
Would it be worth it?

Right, as long as you can completely seal the cement board - this is kind of expensive mass, and I've not tried to hermetically seal the stuff before - it's kind of crumbly, but it's definitely heavy enough if you can find a way to incorporate it.

Check the second page of the "complete section" for a concept illustration on isolation - the "toybox" one... Steve

Or you can use something such as an acrylic polymer cement compound ... One such name is permacrete.

Why not just do what Acoustech suggests Steve? Sounds like it solves these problems once and for all. Or is this a matter for further investigation as it totally negates the 2 leaf concept, at least as it applys to exterior walls. Just wondering outloud. Sounds like the budget will work but who really knows anymore..... On the one hand you have Eric, on the other Acoustech. And to my way of thinking, if I'm not mistaken, that is EXACTLY what this is about......opinion. But I'm not the expert. I DO wish Eric would reply to Acoustechs 101 theory, but then again, I like Westerns, especially the OK Corral type
fitZ

Rick, I'm not convinced of the wisdom in that method as yet - still waiting for answers to my questions and getting what borders on double-talk. So far, I've not had anyone come back and tell me my methods don't work (quite the contrary) so I'm still "from Missouri", so to speak... Steve

The problem with fortifying the outside wall by placing cement board between the studs, even if you can seal it, is that the studs themselves are less dense and form a flanking path for the sound through the outer leaf.

what is the outer sheathing of the garage? Could it reasonably be removed, a dense underlayment placed on the outside, and then the sheathing replaced or something new put on the outside?

Taking the outside off isn't really an option.

Here is a question that my partner in studio and I were talking about.
Is sound more like water or electricity. I know it is sound pressure levels, but follow me for a minute.

So if you had a whole in a dam, it would get wet but for the most part it would hold back the water.
If you had a short in a circuit, then you would have alot of leak and very little(if any) being held in the circuit.

This comes to play in our design in two ways.
1) I think it is un-realistic to think that we will be able to caulk EVERY air gap. There will be some 'small holes in the dam'.
2) We were also thinking of including some of the ceiling joists in the room. We wouldn't attach anything to them or build any of our rooms touching them, but they would pass through our inner room. The reason being that our inner room would have a too low ceiling if we built under them.

So speaking of flanking paths, how bad would it really be to include the joist in the room?

I agree that using "inserts" between studs is not as good as being able to put more full sheets of mass in place - however, sometimes that's not an option. When it's not, consider that lumber is a little better than half the density of gypsum, depending on the species of the lumber, etc - so 3" of solid wood would be equivalent mass to at least half that much wallboard. The downside is that the wood (stud) extends through the initial air gap, reducing it to zero under normal curcumstances. The absolute MINIMUM you should do if adding mass between studs this way, is to use Resilient Channel or RSIC clips and hat channel to mount the inside leaf - better by far would be to build a separate frame, with as much air space as you can steal between the old frame and the new, but at LEAST an inch between frames.

One other alternative, if adding between-stud mass isn't practical, is to put ALL the extra layers on the inside leaf (again, preferably on a separate frame) I've calculated different wall sytems, and with the same air space you get almost the same result by putting 2 layers of wallboard on each side of a wall as you get by putting one layer on one side and three layers on the other. You would need to, for example, instead of putting two layers on each side, put the one layer (say, existing siding) on one side, and instead of just using 3 layers of wallboard on the inside you would need 4 layers to get close to the same performance; even that wouldn't be quite as good as a more balanced panel layout, it worsens the mass-air-mass resonance somewhat which hurts low frequency isolation by a few dB. Still, if it's what you can do, it's good to know what to expect.

Hope that helped... Steve