John Sayers' Recording Studio Design Forum Archive

Hi All,

I'm in the design phase of my first home studio build. Below are my goals, a description of the room, initial ratio work, and a series of first-round questions. Greatly appreciate your time and any assistance you can provide.

/// GOALS ///
- Space primarily for editing and mixing.
- May be used for some tracking (but rarely heavy multi-track recording, due to space).
- There will not be a permanent kit, but I'd like the flexibility should we need to place a small kit on occasion.
- Loudness: Ranges but always below heavy rock.
- It's important I retain resale value on the space. Consequently, I hope to design a room that is both acoustically optimized but still functional as an office or workshop should I sell in a few years. I don't propose (at least for this project) to go full bore on angled surfaces or soffit mounting, etc. Intent is to keep most of the work behind-the-scenes...or easily removed (such as a hanging cloud, hanging traps, etc.). Bottom-Line: I'd like the musician and non-musician, alike, to feel comfortable in this room.. ...Open to ideas, though.

/// BUDGET ///
- $5,000-$10,000 Maximum

/// ROOM DESCRIPTION ///
- Recently built (i.e., brand new) home construction.
- Single-family home; neighbors on egress side about 22' away.
- Most of the basement is finished living space, but I kept one room unfinished for this project.
- The floor is flat, poured concrete.
- 2 1/2 Walls are concrete, on the other side of which is earth.
- The other walls are standard 2x4 construction, on the other side of which are finished rooms.
- Ceiling is constructed with I-Joists and no cross-bridging. Above the ceiling is a hardwood kitchen and large family room.
- Quirks Include an egress window, pre-existing duct system, a lot of exposure to an adjacent bathroom, and existing insulation.

/// MEASUREMENTS / RATIO STUFF ///
- Floor-to-joist distance is 7' 10 3/4". Accounting for RISC-1 clips, channel, double 5/8" GB, and flooring, this leaves me about 7' 7 11/16" Floor-to-Ceiling Height.
- I'm considering 2x 5/8" GB mounted onto the ceiling between the I-Joists, though there is a lot of duct work and piping that may make the task very complex.
- I plan for a dual-frame wall assembly with 2x 5/8" GB. All the widths and lengths below reflect interior edge-to-edge measurements.
- In the example below, the speakers will be at the top of the room, facing towards the bottom.

Referencing Rod Gervais' Room Ratio matrix, I assess the best I can do is use Sepmeyer's and Louden's 2nd ratios, respectively. Those are portrayed in the 2D models below. (Their 1st set of ratios would leave me with too wide a room). Sepmeyer's 2nd Ratio
- H 7' 7 11/16" / W 9' 9 3/8" / L 11' 9 1/4"
- Accommodates a decent walk-in closet that could double as a vocal booth.
- But it's pretty small space. Louden's 2nd Ratio
- H 7' 7 11/16" / W 9' 11 1/4" / L 14' 6 1/4"
- Accommodates a standard-size hanging closet; possibly a good area for an HVAC solution. /// QUESTIONS ///
(1) Which model do you think is the better option? And is there an alternative I'm not considering?

(2) Retaining the egress window's functionality will be required by code. But it would basically be right next to the side of the left speaker, probably creating havoc on frequencies. Thoughts on how I should handle this?

(3) The Louden model would necessitate a double-door closet; I can't imagine double doors facing the speakers is a good thing...Thoughts?

(4) You'll see in the picture that, at the bottom of the room, there is an opening to an adjacent bathroom. There is space leading under the tub...Can this be remedied with just another sheet of drywall applied against the inside of the existing wall?

(5) Apologies as this is more of a construction question. You'll see in the pictures that the concrete walls already have (thin) insulation, mounted with white plastic tarps and screws (this is increasingly common in new construction)...Should I remove this insulation entirely and start fresh with a new outside frame (colored red in the models)?

Thank you again for your help!

- Studio Dude

Hi there "Studio Dude", and welcome!

There will not be a permanent kit, but I'd like the flexibility should we need to place a small kit on occasion.

"Kit"? Are you referring to a drum kit, or some other type of "kit"?

- Loudness: Ranges but always below heavy rock.

Decibels. We need that in actual numbers. It's easy enough to do, with an ordinary hand-held sound level meter. Around US$ 100 for a good one on ebay or Amazon. But don't get one of those Chinese toys, that sell for under 50 bucks: no use at all.

- It's important I retain resale value on the space. Consequently, I hope to design a room that is both acoustically optimized but still functional as an office or workshop should I sell in a few years

Tall order! For a good definition of "acoustically optimized", google ITU BS.1113-6, and look at the section on what is needed to have a critical listening room. That's what you'd need to do to your room, to make it "acoustically optimized". If you still want it to look like a plain old home office or workshop, you are sort of setting yourself up for failure on both fronts. If it meets specs for a critical listening room then it won't look much like a workshop. And if it looks like a workshop, it won't be anywhere close to a critical listening environment. You'll probably have to settle for second best on one of those two options.

I don't propose (at least for this project) to go full bore on angled surfaces or soffit mounting,

So then you DON'T want it to be "acoustically optimized"?

Bottom-Line: I'd like the musician and non-musician, alike, to feel comfortable in this room.. ...Open to ideas, though.

And I'd like a car that drives the same as a Ferrari but costs the same as a Chevy Spark.... I think you and I have similar chances of getting what we want...

- The floor is flat, poured concrete.
- 2 1/2 Walls are concrete, on the other side of which is earth.

That's great! A really good start. It should be feasible to get good isolation here, provided that the issue with the egress window can be dealt with, legally.

- The other walls are standard 2x4 construction, on the other side of which are finished rooms.

But there's no drywall on the "studio" side of those yet, right? Only on the "other room" side?

and flooring,

Flooring? Why? You already have the best possible flooring for a studio, and your ceiling is already so low that you can't afford to waste any height on flooring. Polish or stain the concrete to make it look nice, and it's done. Cheaper too: You are on a shoestring budget already, so save every cent you can by NOT doing stuff that you don't absolutely need to do.

- I'm considering 2x 5/8" GB mounted onto the ceiling between the I-Joists, though there is a lot of duct work and piping that may make the task very complex.

You'll need to hire a structural engineer to OK that: You don't know what the current live and dead loads are on your joists, and you don't know what the structure is rated for, so you therefore also do not know how much extra capacity might be available to allow you to add thousands of pounds of loading to your joists.

- I plan for a dual-frame wall assembly with 2x 5/8" GB.

Why do you want to build a three-leaf wall, when two-leaf is so much cheaper, and so much better for isolation? Is there a problem with your local code that requires that? It wastes so much space, and money, and time. and isolation. If it's a code issue, see if you can get a waiver.

(1) Which model do you think is the better option? And is there an alternative I'm not considering?

Both of your options produce very small rooms, smaller than the minimum BS.1116-3 recommendation, which is 20m2, (215 ft2). That doesn't mean that the room would be terrible: I have designed several that are smaller than that, with good success. However, it does imply extra treatment and poorer acoustics. The smaller a room is, the more treatment it needs. I would suggest trying to make your room as large as it can be. Do you REALLY need a vocal booth / walk-in closet? That same space could be put to much better use for bass trapping, for example. What ratio do you get if you set the dimensions to be as large as possible, after allowing for the inner-leaf wall (assuming that you can get the waiver and avoid building a three-leaf wall).

(2) Retaining the egress window's functionality will be required by code.

Does code permit having two windows in the egress path, back to back? Or must it be one single window?

But it would basically be right next to the side of the left speaker, probably creating havoc on frequencies. Thoughts on how I should handle this?

Turn the room around. Face it the other way. That way, the window is NOT in a critical location, and would also be more easily accessible in the event of an emergency.

(3) The Louden model would necessitate a double-door closet;

No it doesn't! It merely necessitates a solid barrier at the far end of the room. YOU decided to make that into a double-door, not Louden! It could be a solid wall, or it could have a single door in it, or sliding glass doors, or anything else that creates a solid, rigid, massive, sealed barrier.

I can't imagine double doors facing the speakers is a good thing...Thoughts?

It shouldn't be a problem, provided they entire rear end of the room is treated correctly.

(4) You'll see in the picture that, at the bottom of the room, there is an opening to an adjacent bathroom. There is space leading under the tub...

It might just be the photos, but it looks like the sole plate is also not sitting flat on the floor: there seems to be a gap under the left end of that. If so, you'll need to shim that, fill it with backer rod, and caulk it. I would consider putting substantial cleats or blocking up the tub side of those studs, and attaching drywall to those, inside the area between the studs. Caulk to seal airtight, and also add another layer of drywall to the existing layer, visible in the photo, using the "beef up between the studs" method.

You'll see in the pictures that the concrete walls already have (thin) insulation, mounted with white plastic tarps and screws

Is that required by code? If not, then I'd remove it and replace it with insulation that is more suitable, acoustically. Also check if you need a vapor barrier in your wall system, and if so, where it must be placed. You don't want to have TWO vapor barriers in there, and that stuff looks like it might be acting as a vapor barrier too...

Should I remove this insulation entirely and start fresh with a new outside frame (colored red in the models)?

I don't understand the need for that frame: What purpose does it serve? Are you SURE that you code requires it? You'd be wasting a lot of space like that, for no discernible reason.

- Stuart -

Hi Stuart!

Thank you for your thorough (and quick) response. I've spent the last few days digging into your questions.

Are you referring to a drum kit, or some other type of "kit"?

Indeed, a drum kit. I personally don't own a drum kit but I can foresee a rare occasion where we may need to bring one in. But it's not make-or-break and would be atypical.

Decibels. We need that in actual numbers.

I ordered a decent sound level meter. In listening position, my preferred level is 55-70dB . I would be comfortable up to 75dB (if I were jammin' out). I also tested a 900-watt bass amp (and matching 10x4 cab)...this is obviously for large live venues ) With the bass, I'd really be pushing it to reach 85dB...I’d typically stay around the low end of 65-75db (but preferably lower).

If it meets specs for a critical listening room then it won't look much like a workshop. And if it looks like a workshop, it won't be anywhere close to a critical listening environment. You'll probably have to settle for second best on one of those two options.

Definitely open to ideas, including soffit mounting if that's what's required.

It should be feasible to get good isolation here, provided that the issue with the egress window can be dealt with, legally.

I am researching the egress issue. Since the overall basement already contains an egress option (a door to the yard), it's possible that double sliding windows are permissible at this location, though in the future I may need to remove the second window if I were to later sell the home (in order to retain value).

- The other walls are standard 2x4 construction, on the other side of which are finished rooms.

But there's no drywall on the "studio" side of those yet, right? Only on the "other room" side?

That's correct. In my revised diagram below, I show that leaf of single GB -- which faces the finished area of the basement -- as purple.

Flooring? Why? You already have the best possible flooring for a studio, and your ceiling is already so low that you can't afford to waste any height on flooring.

The flooring I have planned is locking composite flooring at .160” (4mm) total thickness.

- I'm considering 2x 5/8" GB mounted onto the ceiling between the I-Joists, though there is a lot of duct work and piping that may make the task very complex.

You'll need to hire a structural engineer to OK that: You don't know what the current live and dead loads are on your joists, and you don't know what the structure is rated for, so you therefore also do not know how much extra capacity might be available to allow you to add thousands of pounds of loading to your joists.

Understand. I had previously asked my building manager about this, and he didn't think it was an issue (he was confident the floor could handle the load). Definitely worth double-checking when I can provide data on the estimated total weight.

- I plan for a dual-frame wall assembly with 2x 5/8" GB.

Why do you want to build a three-leaf wall, when two-leaf is so much cheaper, and so much better for isolation?

This is where I need some help understanding how the cement wall functions vis-a-vis the mass-air-mass system. Does the concrete wall function as a single leaf/mass? Should I account for insulation space, in which case I would frame against the concrete? I've illustrated these two options below: OR

Both of your options produce very small rooms, smaller than the minimum BS.1116-3 recommendation, which is 20m2, (215 ft2)...Do you REALLY need a vocal booth / walk-in closet? That same space could be put to much better use for bass trapping, for example.

There is no requirement for a closet or vocal booth. I was attempting to match a Sepmeyer/Louden ratio, but hated having to cut down on room space...so open to ideas here.

What ratio do you get if you set the dimensions to be as large as possible, after allowing for the inner-leaf wall....

See below: I plopped an example desk in there, illustrating your suggestion that I move the workspace to the bottom half of the room, away from the window. I think it works (even with the door), and the speaker face here is 1 meter away from the back wall. I also drew the area in which there is a rectangular duct running across the ceiling -- this will need to be closed and soffited.

The room ends up with the following dimensions:
H : W : L
91.6875” : 125.75” : 216.5”
Ratio is 1: 1.37 : 2.36

Using the algorithmic tests in ITU BS.1113-6. Sec. 8.2.2.3 (Room Proportions):
1.1w/h < l/h
TRUE: 1.5 < 2.36
////
l/h < 4.5w/h – 4
FALSE: 2.36 < 2.17
////
l / h < 3
TRUE: 2.36 < 3
/////
w / h < 3
TRUE: 1.37 < 3

Thoughts?

It might just be the photos, but it looks like the sole plate is also not sitting flat on the floor: there seems to be a gap under the left end of that. If so, you'll need to shim that, fill it with backer rod, and caulk it. I would consider putting substantial cleats or blocking up the tub side of those studs, and attaching drywall to those, inside the area between the studs. Caulk to seal airtight, and also add another layer of drywall to the existing layer, visible in the photo, using the "beef up between the studs" method.

This is great advice, and good eye! I checked and yes: the sole plate is not sitting flat. I'll pay special attention to fix that. Regarding the tub, the crazy thing is that tub is basically touching the studs save a paper-thin plastic shim in between.

You'll see in the pictures that the concrete walls already have (thin) insulation, mounted with white plastic tarps and screws

Is that required by code? If not, then I'd remove it and replace it with insulation that is more suitable, acoustically.

I plan to remove the tarp and existing insulation entirely. This is what our code says about insulation and vapor barriers: "A minimum of R-10 (continuous roll type) or R-13 ( batt type installed between the studs) Insulation shall be provided with a vapor barrier, installed from the top of the basement wall to a depth of 10 feet below grade or to the top of the basement floor, whichever is less."

With the revised ratios, what do I need to consider for further modifications to the room shape and layout?

So which way did you decide on your concrete walls? Is one better than the other?

Is one better than the other?

Considering he has clay on the other side of his concrete, picture #1 would be fine. It would also allow him to have more space in his room. It would also allow him to modify his room ratio.

If the room was above ground and isolation was very important, of course, picture #2 would offer better isolation as the spring gap would be larger.

Greg