Single room home studio for tracking and mixing

Hi, first-time poster here, though I've been browsing, learning more than I ever thought I'd want to know about studio construction. I'm hoping I've got enough of the sticky-requested information to get started. And sorry in advance for the lengthy post . . . 8-) I'm about to commence construction on a small single-room studio for personal, and not commercial, use in the basement (garage, actually) of my home. For the most part, I'll be the only one recording in here, mostly live vocals, acoustic and electric gtrs, bass, and the rest is all handled with softsynths. I don't have an SPL meter yet (my next purchase), so I cannot give you numbers, but my volumes are typically quite moderate; occasionally a guitar solo will get out of hand (up around 100 dB), but typical tracking and mixing is much lower, say, 85 dB or even much less. My biggest concern is the ability to work late at night without waking up the kids upstairs. The house is a split-level, with the bedrooms on the opposite side of the house from the studio-to-be (north and west walls); the exterior of my nearest neighbor is approximately 40 feet outside my south wall. Our garage is on a concrete slab along the south wall of the house, and the studio to be constructed is located on a roughly ten foot by 25 foot wide strip of it, bordered by the south and west walls, in the rear of the house. Approximate dimensions of the to-be-built room, irregularly shaped, are 15' x 10' x 7.6 (LWH). I will try to figure out how folks are creating all these cool pics I'm seeing on this board; until then, the attachment below will have to do 8-): "B" is the south wall, and both A and B are hollow concrete block ("cinder" block, 10"), and are both below grade for about 4 feet. As you can see the walls D and C to be built are splayed, with the idea of helping out with flutter echo, so that the only parallel surfaces are the floor and the ceiling (7.6 feet). I've read a general rule to help avoid standing waves is basically 1 foot per 10 feet of wall is sufficient here, but I'm interested in input, of course. The frame is wood 2x6, and I expect that the walls will be double 5/8 sheetrock/Green Glue sandwiches hung from resilient channel on the inner leaves (studio side); the exterior leaves on walls C will be the same, but without RC. Exterior leaf of D could be the same, or it could be left unfinished (see below). The exterior leaves for A and B are the concrete block. I'll be stuffing R13 (3.5" of the pink stuff) in between. The ceiling will likewise be double 5/8 sheetrock/Green Glue sandwiches, hung from RC. I will not be floating the floor, though I haven't yet decided what combination of materials I'll be using there. As it is a concrete floor, I'm told to put a vapor barrier down, but I've read where this is not recommended. Some sort of engineered hardwood tiles will be used, with an underlayment of 1/4' foam, but beyond that I'm not yet sure. I'm worried about the flanking noise that'll happen, since the concrete is continuous into the rest of the garage (i.e., I will not be cutting the concrete), and thus to the rest of the house. The drawing also (crudely) shows 2 doors, one along wall C in the unfinished area, and another along wall D, as the entrance to the studio. Both are 36" solid core, and fire rated. The area between D and E is unfinished and contains some water pipes and sewer and gas lines, all located on wall E. BTW, E is unfinished, with exposed studs and old insulation in between. On the other side of E is the family room. Two other important points: First, I'm all thumbs with hardware - I've got absolutely zero ability to do any of the contemplated work. So I've hired a carpenter who is quite flexible with how the room gets built, but I do need to be able to explain to him why things should be done in a certain way, and for this I thank John, knightfly and all the rest of the participants on this board who have clarified some things I never thought I'd understand. Lastly, my budget for completion of this room is approximately $8K, including materials and labor. My questions: 1. Is it reasonable to expect that such a room would be isolated sufficiently so that I could use the room at night at moderate volumes (say, 60 - 85 dB) without waking up the kids, or the neighbors? 2. Should I finish off the exterior leaf of D with double 5/8 sheetrock and Green Glue, or would that cause a 3 leaf effect with the unfinished wall E? 3. How to affix the frame to the floooring? The frame itself is on a double layer of sillseal, but then is bolted through to the floor and attached to the floor joists above. Will this not create a route for flanking noise, or is the fact that both the walls and ceiling are de-coupled from the structure with RC sufficient to mitigate this connection? 4. Is this the best way to set up the doors? 5. Passive ventilation is anticipated from wall D through to the family room on the other side of wall E, but I'm not sure of the materials to be used. Any suggestions? 6. An exhaust fan is anticipated with a register in the wall at the southeast corner of wall C. The fan is set to a switch so that I can control it when recording, but again, I'm not sure of the best materials to use for this purpose. And I need some sort of register damper/cover to reduce/eliminate through-the-vent noise. Any suggestions? 7. Given that the concrete block exteriors are hollow at A and B, how much space should I leave between the outer and inner leaves of those walls? My thanks to all who care to comment.

Anyone? . . . :-( I'll go back over the stickies, see if I missed anything crucial . . . bzb

One thing that jumps out at me is I believe you use RC OR Green Glue but not both. RC is generally used on ceilings when you have to attach to your existing joists. As far as flanking noise, considering what you are planning to record, I don't think this is going to be big problem (I'm sure others who know more will chime in if I'm wrong). Your primary problem with flanking is low frequency and since you didn't mention recording live drums, you might be able to do what I did and just use anchor bolts to screw the bottom plates to the slab. Is there any reason there is so much of a gap between walls D and E? You are going to lose a lot of floor space and anything beyond about a 12" air space (between D & E) is not buying you much. On your point 2) - You WILL create a triple leaf if you finish the "back" of wall D. What you'll need to do is leave it open and then beef up between the studs on wall E with at least a couple of layers of 5/8" drywall. This IS something you can do yourself (no need to pay somebody). Just remove the insulation and then cut strips of dry wall and put them between the studs (I mean right up against the wall too - no air gaps!) and calk the stud/drywall edges at each layer. Two layers would be the minimum - 3 or more would be better. When you get to the last layer of drywall strips, before you calk the last stud/drywall layer, put a wooden cleat (maybe 3/4" to 1") on each edge to hold it all tight. Screw this into the studs (NOT INTO THE DRYWALL) and then calk the edges. That should go a long way to sound proof from the rest of your house. You havent' mentioned anything about the ceiling. Do you already have a finished ceiling? 7.6 feet seems awful low for an unfinished ceiling. How is the roofing system between the house and the garage built? This could be a bigger source of flanking noise than the floor. We'll need a few more details before we can help here. I would council taking your time with the design. Don't rush into this or you might end up spending your $8K and not have a room that meets your needs. As far as your building abilities, you can do a lot more than you think you can. I know because I thought the same thing and I've managed to do a pretty good job (I think) on my studio and it was a much bigger project (3 recording rooms + control room and office/lounge/hallway). I had someone helping me that knew what he was doing but in many cases, he would show me how something should be done and then I'd do the bulk of the work myself after he'd left. Have a little confidence in yourself. We'll provide all the support you need. We're generally a pretty friendly bunch. len

Len - Thanks for taking the time to comment - I really appreciate it, as almost everything everyone says around here is news to me 8-) As to your comments:

One thing that jumps out at me is I believe you use RC OR Green Glue but not both.

I am under the impression that the RC is a de-coupling trick, and that the GG is for damping the sound energy that hits the sheetrock. I know that the GG people don't recommend RC, but that's a more general issue, for reasons of difficulty in construction (i.e., shorting out the RC is too easy), but they specifically state that there's no incompatibility between GG and RC. But of course that's just what I've read, and I'll take your and anyone else's suggestions about this issue. Concerning the low frequencies, you are correct that there'll be no live drums in here, and in fact even the bass gtr is normally taken direct (although that'll change once I lay my hands on an old Ampeg . . .) So, I'll go ahead and anchor the sole plate to the slab. Since I'm using the RC on the walls, I assume it'll be okay to attach the top plate directly to the joists above? The business about the space between D and E is twofold: First, there are sewer pipes (the main cleanout) and also water and gas lines in that area, and I simply thought to leave enough room for someone to work in there comfortably if they had to. Secondly, the door issue: I know that the door tends to be the weakspot, and I thought that perhaps having two solid core doors not in the same plane might be better than having one main door into the studio. Since the town is going to require that the door along wall C be a firedoor, which I cannot retrofit with a door seal kit, I thought I would install a second door along wall D, which would be a solid-core masonite door, with a door sealing kit to improve the seal. The original plan was for a single entryway on wall C, with double doors, of which the first is the firedoor, and the second is the door with the acoustical seal. The airspace between the doors along wall C would be fairly slim, say, 6" or so. Is this a better approach? I'm very interested in input on this, as it would also give me back almost 4.5 feet of studio space. You asked about the ceiling: yes, the ceiling joists are exposed, and the actual measurement (I just checked it again) is 7'4". And that's before I put anything on the floor, so every 1/2 inch is precious! The joists above are 2x10 on 16" centers, approximately 13.5 foot span (I haven't cut into the ceiling that far). Above the joists in the rear third of the room (i.e., from D) is 2 layers of 1/2 inch plywood, topped with a layer of linoleum in the kitchen above; in the rest of the studio, above the joists is 1/2" plywood topped by 3/4" hardwood flooring in the living room Thanks again for your thoughts regarding beefing up the bays of E - most of that could be done, but there are bays where drain pipes run, and the sewer cleanout is actually located in one of the bays, so some of the beefing up will be problematic. And as for flanking through the ceiling (yes I know the ceiling is ridiculously low. . .), will the RC on the ceiling help here? I am extremely grateful for any thoughts you or anyone else might have on these issues. Thanks again. bzb

What are the chances of getting a few pictures to help us get a little better idea of what needs to be done. I'd be most interested in looking at your E wall and all the "obstacles" we'll need to get around. As to the RC/GG question, there is a thread here on just Green Glue that you should probably read. I think that's where I read that using both is a waste of money and time. It's not that it makes things worse, but I don't think it makes anything better. I'll have more to say later. I've got a little studio building (painting actually) to do myself. len

Thanks, again. Pics on the way. bzb

Here are some pics - I tried to resize them, hope they don't violate the rules, and also provide you the information you need. References are to the walls named A,B,C,D and E in the earlier sketch. Looking forward to your comments. bzb

and a few more . . . bzb

Discussed things further with my contractor friend, and we're revising the plan for the walls to provide for double frame walls along wall D, which would eliminate the need for the RC (I think . . .), and leaves open the question of the airspace between the two frames. Utilizing 2x4's in the frame, and measuring airspace from back of stud to back of stud, is a 2" airspace worthwhile? 4"? No difference? (I'd love to leave an 8" airspace, but with an 18" wall, the dimension of the room become silly.) I believe 2" airspace and double 5/8 gypsum boards (w/ GG) allows sufficient room for R19 (i.e., 6.5" for insulation), and completely de-couples the walls. I'll presume this is better than the single frame wall w/ RC I proposed earlier. Along the other walls, again, since they are against the cinder block outer walls, a 2" airspace, and a single frame (no RC), with double 5/8 sheetrock w/ GG. Enough airspace? (Remember, the cinder blocks are hollow block). I'm still wondering what the better procedure with the doors would be. I'd prefer to go back to a two-door design with a 6" airlock between them, but I'm not sure this is as good a design, though it does give me back 4 feet or so of studio space. I'm thinking the two separate doors, with the ~90 degree turn will be quieter. Any thoughts? Thanks again, bzb

I'm not sure how you get only a 2" airspace with 2x4 walls unless you are talking about staggered stud construction (2x6 top/bottom plates, 2x4 studs alternating between one edge and the other 12 OC combined). Can you sketch up a picture of what you and your carpenter are proposing? len

len-morgan wrote:

I'm not sure how you get only a 2" airspace with 2x4 walls unless you are talking about staggered stud construction (2x6 top/bottom plates, 2x4 studs alternating between one edge and the other 12 OC combined). Can you sketch up a picture of what you and your carpenter are proposing? len

We switched to a double frame wall to de-couple, almost like a room-in-a-room. Actually, I think my carpenter counts the airspace from stud to stud - whereas the distance from inner sheetrock layer to inner sheetrock layer is greater. If I do a 3" airspace, there's actually sufficient room for R19, or 6" insulation. I'd draw a sketch, but man am I sucky at this Sketchup thing. I'll give it a go. bzb

As I said earlier, I am majorly sucky at Sketchup, so the following may not be helpful at all. Nevertheless, here is an outline of the revised studio plan, and also a really badly drawn architectural of the proposed wall construction, without the insulation (I cannot figure out how to draw the little squiggly thingie . . . ) Thanks, again. bzb

Common mis-conception here; if you have 3" between frames, and your frames are 3.5" wide each, then the effective air gap (for m-a-m calculations) would be 3.5 + 3.5 + 3, or 10" - which is plenty when combined with a couple layers of drywall on the outside of each frame. IF you do a complete cavity fill, then the standard "fluffy stuff" will give within a couple of dB the same isolation as using the high priced 3 PCF rock wool or rigid fiberglass. If you're in a humid location and want some air circulation between the wall layers, you can use the rigid stuff and fasten fiberglass pallet strapping across the studs to hold it in position AGAINST the wallboard for damping (important) - this would leave an actual air space of about 3" between wall frames, and wouldn't hurt isolation much (maybe a couple dB) - You'll get better isolation staying with 24" centers for framing; if it were possible, the best isolation would be had by letting the panels float in space but practicality says 24" centers :? Check out the REFERENCE section for info on caulking, drywall, etc, there's a LOT there... Steve

knightfly wrote:

Common mis-conception here; if you have 3" between frames, and your frames are 3.5" wide each, then the effective air gap (for m-a-m calculations) would be 3.5 + 3.5 + 3, or 10" - which is plenty when combined with a couple layers of drywall on the outside of each frame. Knightfly - Thanks for taking the time to pitch in. My contractor buddy advised that the total "fillable" space inside would be about 10", as you cite. I suppose that means two batts of R19 to fill. This would be better than leaving airspace?

You'll get better isolation staying with 24" centers for framing; if it were possible, the best isolation would be had by letting the panels float in space but practicality says 24" centers :?

Hey, is that a crack about my Sketchup skills?!?! Yes, we were planning on 24" oc, with the Green GLue, probably on both sides.

Check out the REFERENCE section for info on caulking, drywall, etc, there's a LOT there... Steve

Yeah, I've spent most of the last 2 weeks going through much of that stuff, but there's so much there, I've still got a good ways to go. But what I've already learned is what's enabled me to work to this point with my contractor - who had less of an idea than I did on how this stuff all goes together. It's been quite an education. I'm still interested in anyone's opinions regarding the door layout. We should have about 10" between the doors. The outer door is a fire door (town required), and the inner door will be a solid core wooden door with a door seal kit, such as AcousticalSolutions, or some other's. The door along wall D is likely a solid core wood door as well, and will probably also wear a door seal kit. This leads into the work area 'closet' beyond. And I haven't even gotten to the ventilation, yet. . . . back to the library! 8-) bzb

I'm searching out materials for my little project, and I'm trying to decide between 2 options for hanging the ceiling: RSIC clips and hat channel, or a product made by Kineticsnoise.com called Isomax. I've sought out other threads regarding the Isomax on this board, but haven't yet seen any that seem to endorse them. As between these two, I'm leaning toward the Isomax - if they work well - because they seem able to save me a wee bit of headroom. Though only a wee bit, with a ceiling as low as mine, my room can use every bit it can get. In addition, I am having a hard time finding a vendor in my neck of the woods that carries acoustically lined 'tin' duct, say about 6" diameter. Most of the distributors and local sales offices will sell the unlined ductwork, and even the cotton-based material to use as insulation, but not insulated duct. Any ideas? Thanks again for any insight you might have. bzb

Your door idea should work fine, seals are as important as mass in some cases so that's a good idea. Noticed a comment about cinder block; have you seen the comments that hollow block is ALREADY a 2-leaf wall? Any chance of filling them with sand, or do you not need a lot of isolation? Isomax - haven't used it, need more study time to compare, sorry. HVAC - when deciding on parts/pieces, keep in mind that the noise caused by moving air is approximately equal to the 4th or 5th POWER of velocity; so it's a GREAT idea to keep ducts as large in cross-section as you possibly can. Let your HVAC guy do whatever he needs to do to balance the system, but do NOT let him talk you into small diameter/cross section ducts. Also, don't route ducts (especially cold or warm air supplies to the room) between you and your speakers - dropping cold/hot air between you and a sound source on a sporadic basis is a good way to go insane trying to figure out what happened to your mix and where those weird flanging/doppler thingies came from... Insulation - if your construction is perfectly dry, a complete fill will improve iso by a couple dB over partial fill, and about 10 dB over no insulation at all. With the fluffy stuff, 10-15% compression is a good idea; it helps damping of the drywall panels (a bit like Green Glue, but not as much effect) If you need a fire stop without hard contact between inner and outer frames, using rockwool is usually acceptable to most inspectors - about 6-8% compression of 3 PCF mineral wool should hold it in place and provide an acceptable fire block. No cracks about your Sketchup skills, just saying that theoretically a free-hanging (but sealed) panel would stop more sound than a rigidly fixed (and resonant) one... Steve

60” duct length 6” diameter = 1 cubic foot air Room 16x11x7.6 = 1337 cu ft - 3 changes per hour = 4000 cu ft/hr = 67 CFM 67 CFM = 67x5 FPM velocity in 6” pipe = 335 FPM 8” duct = 56% velocity for same CFM, or 188 FPM I'd use the 8". slower air movement is MUCH quieter. Is there something I should do (besides filling) to mitigate? No, concrete block isn't that bad without earth, better with. Should be OK unless you're into live Death Metal. Does your town want the ENTIRE exhaust to be "tin", or just the part that sticks out of the building, or??!? A tin inner surface won't attenuate much sound at all, even with 20 feet or so. You really need duct board here... Which raises a question I keep forgetting to ask. My assumption all along has been that the 'working' end of this room would be facing wall B, with the monitors facing wall D. Is this the best orientation? It goes from wide to narrow this way, but I'm not sure it matters. Yes it does, although not a lot with that degree of splay; can you show the entire garage, along with explaining why the particular choice of wall placement, etc??!? Steve Oh, also it would help clarify things if you can show an elevation so I can see where your space is in relation to the rest of the house...

knightfly wrote:

I'd use the 8". slower air movement is MUCH quieter.

Thanks for those calculations. 8" it is then. In addition, regarding the need for 'tin' ductwork, it's the entire exhaust that must be hard duct, from the register box in the studio ceiling on out to the fan in the garage. So I'm thinking perhaps installing a silencer at the front end of the duct.

knightfly wrote:

<snip> . . . can you show the entire garage, along with explaining why the particular choice of wall placement, etc??!?

The garage had a 'home-made' wall in-place when we moved in, setting off the rear portion as a bit of a workshop (mostly empty pegboard, as I recall . . .). Although we never (well, almost never) actually pull our cars into the garage, we do use it for storage, and I'd like to hold open the option for my wife to park a car in there on a bad snow day (hasn't happened yet!) As earlier indicated in this thread, the southern and western walls (A and B) were concrete block, and so seemed to be the obvious corner. Further, the northern end of the 'workshop' area (wall E) has the gas lines and sewer lines which I assume might require work at some point, so I thought to leave those exposed. And of course since it's just me in here, I don't need all that much space. I've provided a sketch of the floorplan for the entire garage area, to show where the studio is located within the garage. The drawing itself is not quite to scale, but the measurements are accurate. The exhaust duct will be in the studio ceiling approximately 3 feet in and over from the south east corner (walls B and C), and will run out into the garage, after making 4 90's, will exit the garage along the south wall. I'll try to sketch that too. I also have the floorplan for the rest of the house, if that helps.

knightfly wrote:

Oh, also it would help clarify things if you can show an elevation so I can see where your space is in relation to the rest of the house...

Ouch! My ability to do this in SketchUp won't exist for a few months yet. Perhaps a photo of the front?

more pics - as you can see, all bedrooms are on opposite side of house to proposed studio. Bedrooms on right, studio in garage on left, from front of house.

Hopefully, these'll be the last of my atrocious sketches - floorplans, as requested. Oh, no - one more - I've gotta draw in the ventilation. Wish me luck . . . Thanks, all. bzb

Here's a drawing of our proposed ventilation. We are in discussions with the town trying to get a break from the 'hard' pipe requirement rule. 'Til now, they've required that the entire exhaust pipe be 'hard' pipe, but we're trying to get them to agree that flexduct or Superduct ductboard will be as well. SO . . . , I show here an outline of our proposed ventilation ductwork (a) if they require 'hard' pipe; (b) if we can use flexduct, or Superduct. The first views are overhead, the last is a wretchedly done sketchup of the sideview. Question: Do any of these make sense? I'll be using an in-line centrifugal fan which will be on a speed control, but which could run up to 650 CFM, though I'd never run it nearly that hard. Thanks again for taking the time to look. bzb

Oh, yeah - forgot to ask: I've read that you don't want cooling or heating air to be overhead the workzone, or between your ears and the monitors. Given that these proposed exhaust ducts are over the 'business end' of my little room, will this be a problem? Since it's not cooling or heating, but exhausting? Thanks, bzb

OK, new question: I've had mucho discussions with my contractor buddy, and we've decided to go with a new ceiling, by installing new joists in the bays between the existing ceiling joists, and affixing 2 layers of drywall to that, thereby de-coupling the ceiling entirely, rather than hanging the ceiling drywall on the existing ceiling joists via RC or clips. This should improve isolation. However: from about the midway point in the studio ceiling all the way back to the northern end of the studio, which is along wall D from my original floorplan, there are water and gas pipes, some running parallel to the joists (i.e., in the bays) and some running from bay to bay (i.e., through holes or notches in the joists). While we could fit a 2x6 for a new ceiling in some of the bays toward the middle of the room, in the back of the studio by wall D, my contractor is concerned that we wouldn't be able to get the joist into the bay. All the pipes should be relocated, which would cost me a small fortune I had not anticipated spending. So, the question is: any suggestions about how to do this, or should I go back to the original plan of hanging the ceiling sheetrock from clips? Would it help to hang the back half of the ceiling from clips, and the rest (where we can) build the de-coupled ceiling with new joists? I assume the ceiling would simply operate at the level of the clips, so there'd be no point to the extra expense of the new joists/ceiling. Damn, I thought we might've had an improvement here with new ceiling joists. Oh, well. I'll try to add some pics to illustrate my problem. Thanks for your thoughts. bzb

And some more pics about the ceiling joists . . . Sorry some of them are so dark. bzb