New England detached garage one room studio

the interior walls & ceiling won't be attached to the exterior structure. is floating the wrong word to use?

I believe it's decoupled

the interior walls & ceiling won't be attached to the exterior structure. is floating the wrong word to use?

Yup! :) Like NativeLuv said, what you are doing is "decoupling" your innear laf from your outer leaf, which is most definitely a very good thing! So that's fine, and don't worry about my comment. "Floating" is something else, which can also be good, but is really hard to do right. Floating your walls means that you build your entire inner leaf on top of some kind of resilient support, such as neoprene or EPDM or something like that, which acts as a spring, so that the wall does not transmit sound to the floor. It's not a bad thing, but getting it right is not easy, as it requires that you must calculate the final mass of your walls and ceiling accurately in advance, then figure out what type of material you can use to float that mass, how much of it you need, and where to place it so that the entire wall floats evenly, compressing the resilient material perfectly to the middle of the range where it will act as a spring. If you put too much mass on it, then it "bottoms out" and flanks instead of floating. If you put too little mass on it, then it doesn't compress enough to float, and once again it flanks instead. If you get it right, its a good thing. But getting it right ain't easy, and getting it wrong means that you wasted a lot of time, effort and money for nothing. You'd normally only try to float your walls if you needed extreme isolation, beyond what most people need, but that doesn't seem to be the case with your build. So you are "decoupling", not "floating", and that's perfect! I just got a bit concerned when I saw your "floating" comment, and wondered if you were doing it right, but you are not even trying to do it at all, and that's fine too! - Stuart -

so euh, what's the difference? In order to "decouple" you need to "float" it. Decoupled would mean no flanking, right? How do you make a construction not flanking? By "floating"? or "decoupling"? or maybe both? :horse:

Soundman2020 wrote:

the interior walls & ceiling won't be attached to the exterior structure. is floating the wrong word to use?

Yup! :) Like NativeLuv said, what you are doing is "decoupling" your innear laf from your outer leaf, which is most definitely a very good thing! So that's fine, and don't worry about my comment. "Floating" is something else, which can also be good, but is really hard to do right. Floating your walls means that you build your entire inner leaf on top of some kind of resilient support, such as neoprene or EPDM or something like that, which acts as a spring, so that the wall does not transmit sound to the floor. It's not a bad thing, but getting it right is not easy, as it requires that you must calculate the final mass of your walls and ceiling accurately in advance, then figure out what type of material you can use to float that mass, how much of it you need, and where to place it so that the entire wall floats evenly, compressing the resilient material perfectly to the middle of the range where it will act as a spring. If you put too much mass on it, then it "bottoms out" and flanks instead of floating. If you put too little mass on it, then it doesn't compress enough to float, and once again it flanks instead. If you get it right, its a good thing. But getting it right ain't easy, and getting it wrong means that you wasted a lot of time, effort and money for nothing. You'd normally only try to float your walls if you needed extreme isolation, beyond what most people need, but that doesn't seem to be the case with your build. So you are "decoupling", not "floating", and that's perfect! I just got a bit concerned when I saw your "floating" comment, and wondered if you were doing it right, but you are not even trying to do it at all, and that's fine too! - Stuart -

Thanks, Stuart. I'd always heard of interior "decoupled" rooms casually referred to as floating, but I understand the technical difference now. Please consider my walls officially decoupled!

Decoupled would mean no flanking, right? How do you make a construction not flanking? By "floating"? or "decoupling"? or maybe both?

Yeah, but I think Ron is talking about decoupling his inner leaf from his outer leaf, not decoupling one or both of them from his floor. They'll still be coupled to the floor (since they wont be floated) but they'll be decoupled from each other as they are on separate frames (decoupled except via the floor, of course, which I guess is not an issue for Ron). I think? At least, that's what I understood! Ron, do you have a detailed SketchUp model of exactly what it is you are doing? Maybe Ro is right and I misunderstood what you said.... - Stuart -

aaaah, right. yeah, that would be considered "decoupled" (aaaaaargh, semantics) Perhaps it was I who misunderstood.

Regarding the questions on vapor barriers, etc, check out this web site's articles. In particular, this one addresses construction for a cold climate structure. http://www.buildingscience.com/document ... ull_view=1

Soundman2020 wrote:

Decoupled would mean no flanking, right? How do you make a construction not flanking? By "floating"? or "decoupling"? or maybe both?

Yeah, but I think Ron is talking about decoupling his inner leaf from his outer leaf, not decoupling one or both of them from his floor. They'll still be coupled to the floor (since they wont be floated) but they'll be decoupled from each other as they are on separate frames (decoupled except via the floor, of course, which I guess is not an issue for Ron). I think? At least, that's what I understood! Ron, do you have a detailed SketchUp model of exactly what it is you are doing? Maybe Ro is right and I misunderstood what you said.... - Stuart -

Unfortunately I don't have a sketchup model, but you are correct. The walls are only coupled via the concrete slab, which from what I've read on here is fairly minimal as far as flanking noise. We're also taking care to seal the sill and bottom plates with acoustic caulking. I'll try to work on a sketchup model soon. Thanks!

The walls are only coupled via the concrete slab, which from what I've read on here is fairly minimal as far as flanking noise.

OK, that's what I figured. All is well, it seems! - Stuart -

hey everybody! wow, things are moving quickly now. we've insulated the ceiling, and trying to finish the drywall on it this week. forget dogs, drywall lifts are a man's best friend. also running our wiring. the panel is in the airlock and we're running isolated grounds for most of the outlets, with a star grounding situation outdoors. needless to say, i'm pulling the wires, but an electrician friend is doing the installation for me. some new photos: we built a tiny airlock between the outer & inner door. planning on beefing the door with the trunk rubber per Rod's book as well. had no idea a solid core door without a hole for the doorknob can be had for around $50 at home depot/lowes. we'll be adding a couple layers of plywood (drywall i thought would get messed up by equipment load in) + green glue. working on decoupled inner room's rafters more soon. thanks again for all the help!

Hey Ron. Progress! Great! I'm confused about your "decoupled" inner leaf rafters: They are the light-colored wood in the photos, right? And the darker colored wood is the existing outer-leaf truss, right? So how are the inner ones "decoupled"? Maybe its just the angle of the photos, but they look as if the light colored ones are touching the dark colored ones.... - Stuart -

Nice job! Exciting stuff! Soundman, I've seen this build in person (as of several weeks ago) so I can tell you that the new wood was used to modify the existing rafters. So not all the new wood is for the inner leaf! That said, it is hard to tell whether the inner leaf is coupled to the outer leaf. Ron, you definitely want to get this right.... if these 2 leafs are coupled together then much of the isolation you're working so hard to get will be compromised. Broadly speaking, the joists/rafters should be attached ONLY to the inner leaf wall assemblies. You may already have this right, but we're watching your back here dood..... 8)

I can see where the confusion is. The light colored wood highest up are for strengthening the existing rafters and adding new trusses to support the additional weight from the drywall. the interior rafters are made out of the same wood, but are only attached to the new interior walls, absolutely no connection between the inner and outer "rooms" other than the concrete slab. Thanks!!!

Ahhh! OK, now I get it! In the first photo that says "working on decoupled inner room's rafters" it seriously looks like it is all the same structure, but the later photos make it a bit more clear. I thought all the new wood was inner. Gotit! Looking good! That's a nice high ceiling you are going to get there. Excuse me while I turn green with envy... :mrgreen: - Stuart -

Hope you guys don't mind the copious amounts of photos I'm posting here. Very exciting, we got most of the drywall on the ceiling last week. The idea being that the inside out design wouldn't work for the ceiling, far too heavy to lift sections into place. This way we were able to stagger most of the joints. Some ideas for ceiling treatments include floating a cloud or two, or attaching shallow boxes full of ultratouch to strategic spots, or even framing out the entire thing and covering with ultratouch. Any ideas? I was thinking of maybe leaving the ceiling (caulked & mudded of course) until we finish all the walls with ultratouch and get our bass traps in the corners. Maybe see how it sounds? I wondered if the angled ceiling and concrete floor might make the room live in a nice way? We are planning on testing the room when we get the walls finished, see where the problems are. Thanks again for all the help on here!! Ron

Sweet! Nice progress! Regarding treatment, You'll definitely want some absorption on the ceiling, certainly at first-reflection points on the ceiling, and also I'd recommend getting some above any prime recording areas (such as drum kits). I'd wait on the rest of the treatments to see how the room is, you don't want too much high frequency absorption. I need to come down and take a gander again soon!

sounds good. I'll plan on a couple boxes at first reflection points between my monitors and listening position, and maybe a couple over the "live" area. ha! funny to divide such a small room. thanks again! ron

Kick ass looking ceiling Ron, is this gonna be all one room?

Just bought a bunch of Ultratouch and a box of 6" impaling clips. Wow, that stuff is tough - almost impossible to cut. A razor blade just skims over the surface. I ended up using an 8" carving knife and a carbide sharpener that had to be used before every cut. Buy the special knife they sell for cutting it. And forget impaling it - it's like trying to poke a hole in leather. They ought to ship a bunch over to Iraq to replace the kevlar vests. I had to wear a dust mask and goggles to protect my eyes from all the cotton dust. I didn't the first time and it felt like sand in my eyes towards evening. But it's not itchy on your skin. Next time I'll wear long sleeves and use mineral wool. It''s much easier to fab.

Yeah, if you have to cut the Ultratouch, that's no fun. I've never bothered, it's pretty compressible so you can usually stuff it into the available space.... even the smallest batts (16"x3.5"x95") will stuff into a surprisingly small space.

Maine Green Building Supply where we bought the ultratouch told us you can use a table saw if you reverse the blade (!). Also recommended was an old electric carving knife, which i'm going to try to locate at the goodwill later. I'll let you guys know how it goes. Yes, just one room. I'm pretty used to working that way now. I mean there are some monitoring limitations, but I like being in the same room as the musicians. And I think we'll get better sounds out of the larger space too. I might build a couple combo amp sized iso boxes for live band tracking, but not immediately. Ran all the electric last night, very exciting! Thanks! ron

ideaofnorth wrote:

Yes, just one room. I'm pretty used to working that way now. I mean there are some monitoring limitations, but I like being in the same room as the musicians. And I think we'll get better sounds out of the larger space too.

:thu: A couple amp iso boxes can definitely make sense in that space, if it turns out that you need them. Also, good gobos will be a must in a one-room studio. I built mine 2' wide and 6' tall, but if I had it to do over again I'd probably make them 4x4 (and a few 2x4, made so that I could stack them horizontally to get the 4x6 size). I find that with gobos, good room placement, and good mic technique you can get surprising iso.

Another update. So, we finished applying ultratouch to the interior walls, and built 4 boxes for the ceiling. The ultratouch was tough to get to stay up. I think it might be easier with 16" on center walls, but 24" was just too wide to get the kind of compression you need to keep it in place. we tried the little metal insulation rods and even just nailing the top of the batt to the bottom of the top stud. i ended up using some roofing nails with a little plastic washer through the batts to hold them up, upholstery style. we measured and figured on about .25" of the nail going into the drywall which is 2 layers of 5/8" with green glue. I did get an electric carving knife, but found just tearing it by hand, phone book style, worked the best and most efficiently. It will compress into spaces and neaten up pretty well. We also ran electric from the main panel in the house to a little subpanel in the studio. We ran one loop circuit of regular outlets for lights & stuff, and then ran around 8 individual breakers to individual isolated ground outlet for instruments & recording gear. Those isolated grounds run to a star grounding situation behind the garage. So, I've been rushing to finish because I had a jazz session (Jeff Platz quartet featuring the amazing Daniel Carter) booked for a couple weekends ago. We made the deadline, and I was really pleased with how the room sounded. Not overly dead, actually, I think because of the exposed sections of ceiling and concrete floor. Room has a very warm sound, and most importantly the band felt really comfortable in there. An added bonus was how well the isolated ground worked. Jeff uses a 70s silver face deluxe reverb that we've had RF and noise problems with at other places. It was super quiet and clean in the new space, sounded incredible. This inside out design, Rod's book and of course all the great advice I've received here really, REALLY has paid off. We're on a fairly busy street, and during the session we had some incredibly quiet moments (solo clarinet, etc), and you could've heard a pin drop. No noise from outside. Conversely, I've had someone beating on a drumset and from the outside it really sounds like someone watching tv, very little bleed at all. The weak spot right now is the doorway, but we're planning on beefing up both doors with an inset layer of plywood w/green glue, and another stop with trunk rubber gasketing as in Rod's book. My current to-do list: - Put up fabric (Osnaburg I've decided on) and trim over the Ultratouch. - Paint the ceiling. - Buy & install the minisplit. - Build and install the window plugs (they're covered in 2 layers of drywall for now). - Do some testing and see what's happening frequency-wise. But the nice thing is the room is operational for the time being. Here's an mp3 of one of the takes from that session, if anyone's curious how it's sounding: http://www.peapodrecordings.com/shared/16_IMPROV_V6.mp3 John McClellan's "Blair Witch" style drumming.

Fabulous, Ron!