Advice for Sound proofing room

[Matt K]

Under contract for a house. Planning on converting a one car attached garage into a studio/office. Any advice on how to make it as soundproof as possible? Mostly concerned about leaking sound out; not necessarily worried about noise from the street. Thinking particularly about adding some drywall walls filled with… something which would reduce my square footage slightly but should keep most of not all sound out of the main house due to the air gap.

Anybody do a similar project ?

[SGH]

The best resource I found was F. Alton Everest’s books on acoustic design. Basically, block transmission with air, mass, or both. Window A/C instead of tying into central HVAC. Outdoor threshold seal on studio door. Consider slightly non-parallel walls for inner shell to lessen flutter echoes which are hard to tame after the fact. Avoid square dimensions to minimize room coloration. He covers all these and more in an easy to understand manner, and has low-budget suggestions.

[SGH]

You’ve figured out the basic start: inner walls (and ceiling) with an air gap isolating from the main building. Fiberglass in new walls, drywall on both sides. You can buy a special rubber mat that goes between studs and drywall for additional dampening. He mentions using different thickness drywall inner vs outer to minimize resonance. Like I said, a valuable book.

[Doug Elliott]

I've written about GreenGlue before... I used it in my house. You do a double layer of drywall, with a thin layer of GreenGlue between them. It's a non-hardening gel that dampens vibration between the drywall layers.
https://www.greengluecompany.com/noiseproofing-products

It's in the ceiling between my shop and the piano room above. I also put fiberglass in the space. There"s virtually no sound transmission either up or down.

And I used ridgid fiberglass duct board for the air ducts to my shop. That's amazing stuff, it really dampens any sound from going through the duct.

[sterb225]

Matt - send me an email if you want some help. My favorite task at work is the design/building of residential screening rooms for the ultra-wealthy. I have a few tricks up my sleeve and can help you skip common mistakes and clearly communicate your needs to the general contractor. The lengthy response I was in the middle of writing here disappeared when I tried to preview it!

[Matt K]

Fortunately / Unfortunately depending on one's point of view, I won't be able to tie into the HVAC system. I'm probably going to end up installing a split A/C, which would cost WAY less than figuring out some way to get a duct over to this garage. The layout of the house is basically it started off as small house on a single lot and over the years it's absorbed three lots and had additions done, so it resembles most of my trombones in that regard.

Great leads so far everyone, thanks! Looks like a combination of designing the room right and a bunch of this green goop and I might be in ship shape!

Matt - send me an email if you want some help. My favorite task at work is the design/building of residential screening rooms for the ultra-wealthy. I have a few tricks up my sleeve and can help you skip common mistakes and clearly communicate your needs to the general contractor. The lengthy response I was in the middle of writing here disappeared when I tried to preview it!

Email inbound! Also lets talk about that preview getting sucked up. I've heard a few people say it's happened to them but it's super frustrating to debug because I've never had it happen to me as far as I can recall since we set the site up.

[AndrewMeronek]

I haven't done my own room yet, but I've seen pitfalls with acoustic design a lot recently. People thinking that acoustic panels help prevent transmission through walls (they don't help much), installing in-ceiling speakers and then expecting a person hold a mic pointed at the ceiling will work just fine . . .

It's definitely worth putting some thought into.

[harrisonreed]

The one project I know of involved the person building a room and floating it inside the existing room, about 4 inches between the walls. It was complete with wood support structure, HVAC, and acoustic insulation, just like the room it was inside. All wood inside, and wood floors. The inner door acted like an air lock and the outer door was the original door that opened outwards. It even had a window to the outside (it was an apartment).

No sound escaped from it, other than perhaps from the window. The guy was able to practice all day and no one was bothered.

No idea how you would deal with building codes, etc.

[Matt K]

I live in WV so getting it up to code isn't going to be hard. I was thinking basically the same thing... kind of like a floating cube inside the room. One one side it would be a lot more than 4" too. The way it's structured, I think I can put a hall way in where the current back of the garage is, which would lead to the exterior. Maybe even have room for storage of some kind on top. The garage now is super tall because the original house has a basement, so it's a little elevated, but the garage is at ground level. So it goes almost to the roof of the house. I might even be able to put a room on top of this room if I got creative... but then the acoustics wouldn't be as good...

[CharlieB]

Also lets talk about that preview getting sucked up. I've heard a few people say it's happened to them but it's super frustrating to debug because I've never had it happen to me as far as I can recall since we set the site up.

I have similar problems posting.
Sometimes my message disappears.
This seems to be time related, as it only happens if I have kept the Reply box open for a long time, either because of interruption, or too much time spent composing. My defense is to always copy the text of the message to another file. Then, if my message disappears into TC Never-Never Land, I can exit and re-enter Trombone Chat, retrieve my saved text, and send it promptly. A bit of a PITA.

[Matt K]

Also lets talk about that preview getting sucked up. I've heard a few people say it's happened to them but it's super frustrating to debug because I've never had it happen to me as far as I can recall since we set the site up.

I have similar problems posting.
Sometimes my message disappears.
This seems to be time related, as it only happens if I have kept the Reply box open for a long time, either because of interruption, or too much time spent composing. My defense is to always copy the text of the message to another file. Then, if my message disappears into TC Never-Never Land, I can exit and re-enter Trombone Chat, retrieve my saved text, and send it promptly. A bit of a PITA.

Can you answer the questions in this thread and anyone else having the issue, please do so as well.
viewtopic.php?t=31941

[nebtrombone]

When my kids were young I went through the process of talking to contractors about soundproofing a room in my basement. No one was able to assure me that the room they would be building would isolate the sound of the trombone to the level I needed, so I considered looking for a used Wenger Module on military auction sites. I found a few, but they were pretty expensive and weren’t in great shape. I decided to check out the Whisper Room (whisper room.com) I found a 4X8 room with a window and ventilation. It has been my home practice room since 2004 and I can play night and day and not disturb others. It was a good investment and if I move I can take it with me.

[texascurt]

If you aren't concerned about it being "perfect" there are lots of good budget options. I recently built out a podcast and recording studio, and didn't want to spend a ton of money.

It's really about decoupling materials to reduce/elimination vibration. I opted to do a double layer of 5/8" drywall on all the walls and the ceiling, but instead of doing it the "good way" (ie what Doug recommended with the green glue) I got some thin foam strips to create a slight gap between the drywall sheets. Another good strategy is to frame a double wall, with a gap in between the two. The downside is that it eats up square footage. I also put a decent grade of carpet down, with a heavy rubber mat under the carpet.

Since you'll have a dedicated AC system you've eliminated the issue of transmission through ducts. Just be sure to have some distance between the unit and the room so you're not getting a ton of fan motor noise.