John Sayers' Recording Studio Design Forum

Hello everyone, I'm new here, I've been reading about studio design stuff, materials, etc. I want to build a home recording studio, but I need help on the design. I did a sketch, but I don't know if it's any good. PLEASE HELP!!! My available space is 29'x21.5'. Any suggestions, or ideas, on what the design should be?? I would like a control room, drum room, and vocal / guitar room, plus a waiting room. Any help will be greatly appreciated. Thanks.

Hi JMS, and Welcome!

Your basic layout looks reasonable, but I wouldn't cut off the front corners of the CR like that: It would be much better to use them for soffit mounts.

Also, I'm guessing that this is just an early sketch, wince you don't show any isolation at all? Do you plan to add the isolation walls, doors and windows later?

Please also provide more info about what it is you want to do there, if this is a commercial facility or just a hobby studio, etc. And the most important of all: your budget!

- Stuart -

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I want this studio to amaze people. "That'll do" doesn't amaze people.

Hello Stuart,

This is gonna be a hobby studio, I'm gonna use it to record my band, and other local bands, friends of mine. I do need some isolation from my neighbors, I don't want to disturb them. I was planning on using an insulation called Roxul SafenSound, plus double layer of 5/8 drywall with QuietGlue Pro inbetween the two sheets of drywall, for soundproofing, do you think that's enough? Also, I was planning on floating the Control Room, to isolate it from the drum room. I'll be doing all the work with the help of my bandmates, so that's a big savings on my wallet there.

Soffit mounts, is that when you mount the speakers inside the wall correct? What else do you recommend I should do?

Thank you.

OK, then your first order of business is to put some numbers on that: You need to measure two things:

A) "How loud are you" (get your entire band together, get them to belt out the loudest song they can think of, at the highest possible level, and measure what that level is with a sound level meter (not expensive: 50 bucks or so on e-bay).

B) "How quiet do you need to be". Two approaches here: get your neighbors help, to tell you you what THEY think is acceptable, by playing loud music on a full-range system while slowly turning it down until they are happy. Measure that level. Or call your local municipality for a copy of the noise regulations, which sill state the actual legal limit.

Subtract "B" from "A", and that is how much isolation you need, worst, case, to keep from getting beaten up by your neighbors or fined by the cops.

With that number in hand, you can then look a the various ways of obtaining that amount of isolation with different types of construction, and decide which one bests fits your budget and building skills.

Perhaps, but you'll never know for sure unless you do the test to come up with that number!

Correctly floating a floor is not an easy task! And not cheap either. Whatever budget you had in mind, add a zero on the end.

Before you go any further with that line of thought, read these two, carefully:

viewtopic.php?f=2&t=8173
http://www.nrc-cnrc.gc.ca/obj/irc/doc/p ... /ir802.pdf

And if you DO still decide to float, then float the live room, not the control room. Float the place that will be MOST noisy, not the place that will be LEAST noisy...

Yup, that's it. More correctly called "flush mounting", but the not-so-correct term of "soffit mounting" has kind of permeated the studio industry, so that's what everyone calls it.

Lots!

But start with getting your isolation number and basic construction method figured out. Then you can move on to things like room geometry and suchlike...


- Stuart -

_________________
I want this studio to amaze people. "That'll do" doesn't amaze people.

I did measured the sound the other day and got 113 dBs, so using the roxul insulation and the double layer of drywall, I should be getting a STC rating of 55-60, which is good for my area, but if I can get the drum room down to 40dB, that's even better. I have a budget of 20k for construction materials.

Great! You already have a number! Way too many folks come here without a clue as to what they need, so it's good to find someone who does? Your measurement sounds about right too: 113 dB is roughly what you'd expect for a typical rock band playing normally.

OK, so you are aiming for around 50 dB of isolation. That should be doable with your planned construction, but just to clarify:

Yes, but that should be TWO double-layers of drywall. The "wall" around each room is actually two "leaves" separated by a large air gap, with the insulation filling (or mostly filling) the gap. Each "leaf" will consist of 2 layers of 5/8" drywall on stud frame. The outer leaf is your existing structure (garage?), which might need beefing up of modifying in some other way: post photos so we can see what you have, and suggest what needs to be done. The "inner leaf" for EACH ROOM is what you will build, and consists of a new stud frame, resting only on the floor (not touching the existing structure anywhere!), with two layers of drywall on it. Each room has its own inner-leaf, which does not touch the inner-leaf of any other room, nor of the existing building. Each room also has an inner-leaf ceiling, that rests only on the new inner-leaf walls, also not touching any other ceiling, nor the existing roof.

That's about it! Add those details to your SketchUp model, and also add in the soffit-mounts, then post the update here (with some photos of the place as it is now), so we can suggest the next steps.


- Stuart -

_________________
I want this studio to amaze people. "That'll do" doesn't amaze people.

Hi Stuart,
Here are some photos of what I have right now. So, what do you suggest I should do to beefup the outer walls?

Put more mass on it! Either outside (easier) or between the studs (also works). For example, an extra layer of the thickest, heaviest OSB you can find on the outside would be great. Or some such.

_________________
I want this studio to amaze people. "That'll do" doesn't amaze people.

If I put the extra layer of OSB or soundboard inside before the double layer of drywall, would that work too?

You need the mass on BOTH leaves, not just the inner-leaf.

Also. looking at that construction photo, to me it looks like you are trying to float your studio? At least, I see a gap underneath the structure that supports the subfloor and walls, with what looks like some kind of pad under the corner... Maybe it's just an optical illusion?

But either way, it looks like you have a large air cavity under your floor: How did you build that, what is its purpose, and how do you plan to treat it? Right now, it appears to be a very good resonant cavity: if you don't do something about it, you will be building your studio on top of a drum head!

- Stuart -

_________________
I want this studio to amaze people. "That'll do" doesn't amaze people.

Hey Stuart,
I don't have a pad underneath the subfloor and walls, it's just normal conventional construction (foundation, joist, subfloor, with fiberglass insulation in between the joists) I'm planning to do another layer of 3/4" OSB for the subfloor with GreenGlue in between the two sheets. Then for the drum room I think I'll use the U-Boat Floor Floaters to float that room. What do u think?

JMS

Normal conventional construction??? For a STUDIO? Meant for recording DRUMS!!!

I guess the question is: Why didn't you just build it directly on a concrete slab, when you had the opportunity to do so? Now you have an unintentional and unwanted (but nevertheless very real) resonant cavity under your entire studio that is going to be pretty hard to deal with.

I doubt that will be enough. How deep is the cavity? (from the underside of the subfloor to the bare ground underneath it).

Float a floor on top of a resonant cavity? What I think, is that you should read these, very carefully:

viewtopic.php?f=2&t=8173
http://www.nrc-cnrc.gc.ca/obj/irc/doc/p ... /ir802.pdf

It doesn't look like you have the structural system necessary for successfully floating the drum room. At best you could maybe build a drum riser in there, but you don't seem to have the height needed to do that either!

I also don't see how you are going to be able to build your inner-leaf walls on top of that thin, flimsy sub-floor. Did you take that into account when you built the floor framing? I mean, do you have heavy joists specifically placed and braced at the locations needed to support the inner leaf?

One more point: Your roof seems rather low. Once you get the inner-leaf in there, the final ceiling height is going to be pretty low. Not what you want for a drum room at all! Is there a reason why you didn't build the roof higher, when you could have?

I just see a lot of red flags waving when I look at those pictures. It seems to me that something just isn't right here, overall. As though there was no consideration at all given to isolation or acoustics in the design of this building. It looks like the basic design concept is much more of a garden shed than a studio. How much experience does your contractor have with building studios? Did you check his credentials in that area?

Building a studio is nothing at all like building a house or office. Waaaay different.

Maybe you could post your original design specs, so we can take a look at them, and see just how well (or how poorly) this structure meets them.


- Stuart -

_________________
I want this studio to amaze people. "That'll do" doesn't amaze people.

I used 2"x8" floor joists 16"o.c., with a beam in the middle under the floor joists for extra support, with double layer of 3/4" OSB Floor sheets, so I don't think it's a flimsy sub-floor at all. The cavity from the underside of the subfloor to the bare ground underneath it is 16".



I have a ceiling height of 9'6", how much ceiling height would I need to build a drum riser?

But what about the areas BETWEEN those joists? Your new inner-leaf framing will be resting only on the OSB between joists, unless you specifically put extra joists under the location where it will go. There's going to be a lot of weight resting on that OSB: 2 layers of 5/8" drywall weighs about 24 kg per square meter, plus framing, plus insulation, plus whatever treatment is hanging on the walls and ceiling, plus doors, plus windows, plus HVAC.... By the time you add up all that, it's a lot to have resting on that unsupported OSB. Don't forget that it isn't just the inner leaf walls themselves that you have to think of: you have the weight of the inner leaf ceiling too (plus framing, plus insulation, plus... etc.). Thousands of pounds, in total.

I can't see how you are going to get 9'6" ceiling height in there! It seems to me you are not considering the inner-leaf at all! Just the framing alone for that is going to take out at least 7 to 9 inches, plus the drywall itself. You don't seem to be allowing for the finish flooring, either. And then there's acoustic treatment to consider...

But apart from all that, let's say you end up with a final inner-leaf ceiling of 8'6", for argument's sake. Your drum riser is going to take up around 8", leaving 7'10. Your ceiling treatment is going to take up another 8" (at least). You are down to 7'2". If you have your overhead mics on the drums at a typical height, that would set them close to 6', placing them about a foot-and-change below the ceiling. I don't know about you, but I normally end up with strange reflections and artifacts if I have my mics that close to the ceiling... I like to have lots of air above my mics.

But if that's all the space you have, then that's what is is going to be, I guess!

At least you have some decent depth in there! The resonant frequency of that cavity is around 32 Hz. From 32 Hz to about 47 Hz the floor is transparent, acoustically (sound doesn't even see it: passes straight through). It starts isolating at around 63 Hz., and isolates well at around 95 Hz upwards.

That's not too bad, for isolation, presuming that the cavity is sealed air-tight all around, all six sides. If there is any opening at all, then the isolation of your entire structure is limited by mass law relevant to two sheets of 3/4" OSB, which is roughly 18 dB at 100 Hz, rising to 25 dB at 500 Hz.

Roughly STC-29. That isn't very much at all for drums! Is that within your design specs?


- Stuart -

_________________
I want this studio to amaze people. "That'll do" doesn't amaze people.

You had a concrete slab and spent xtra money to build a wooden floor? To what end? Come on man, your half way into this project, with information that many will out-right refuse to accept based on what we know to be acceptable practice.

You have 8 foot tall walls with no real ability to decouple without reducing you interior ceiling height, You guys have your work cut out for you...


And if you keep moving in this rabid forward progression, it is not going to end pretty, assuming it does.


Good Luck,

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Brien Holcombe
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Sound: You can't stop it, you can only try to contain it.