Refining the Design of a Multi-Studio Facility in NY

[Dylanmcdougle]

Greetings all,

My name is Dylan McDougle, I’m a studio owner & recording and mixing engineer based in New York City. Over the past 6 months I have been reading through posts on this forum night after night (and not sleeping much), and at the forum’s recommendation have read through the second edition of Rod Gervais’ book at least twice. I have to say, I could not possibly be more grateful for the community that exists here. The depth of your knowledge, willingness to share, and patience with those of us who are learning is truly a gift. Sincerely, thank you. I plan on sharing all of the tools that I create (calculators and sketch-up models) and any resources I come across throughout this process with the forum as a way to begin my contribution to this community.

##PROJECT

When I began my research, I was only trying to satisfy my general hunger for information peripherally related to my occupation – I was doing it with no project in mind. Well, as the universe works, I have recently been given the exciting opportunity to work with a team of people to build a multi-room studio in my area, and have been designing the space for the past couple of weeks. It will be a multi-studio facility for the writing, production, recording and mixing of hip-hop and pop/electronic music. In my experience working in and operating studios over the past 10 years, several smaller multi use rooms are more profitable than separate, more specifically designed tracking and mixing rooms. Currently, we’re at a hybrid design/budgeting stage. When we have determined what a workable design and implementation will be for this space, we will make the budget-driven decision to either build it all in one go, or leave room for our second CR/booth to be built in a second phase. Through reading many design and build posts here, it has become very clear to me that the earlier you all are consulted on design considerations, the less headache exists for all involved. With that being said, I’m happy to share with you my design at its current stage:

HERE IS MY SKETCHUP MODEL




##SPACE

Our raw space is 50’ 1 3/4” l x 27’ 7 1/2” w, with a maximum ceiling height of 124” and a minimum height of 108” in some places due to structural steel beams. I have mapped out the large ones in my sketch-up model, however there many more ceiling obstructions including smaller steel beams and sprinkler pipes that I’m currently working to measure and model. This is critical to my HVAC implementation.

1 - BUILDING STRUCTURE.png

The existing floor is a relatively thick concrete slab (my guess is 12” or thicker) with a basement below. The existing roof has corrugated steel visible from the interior of the space, and I'm currently investigating the materials layered above that. Take a look at the photo below for detail, and please ignore the framing and electrical in the photo - it is being demolished. The majority of the space has no structure above it, though on the right side of the steel beam in the floorplan (above the podcast room and entrance area) there is a residential unit. I’m going to hold off on designing any modifications to our outer leaf until I have the specific details of their composition, though I intend to do everything possible to minimize transmission into and out of the facility. I realize this is also critical to my isolation to the outside world, and it is not being ignored.

2 - ROOF.jpg

##DESIGN

-Room dimensions

2 control rooms - 15.5’ l x 10’w x 8’h
2 vocal booths - 5.5’ l x 10’ w x 8’h
1 live room - 11’10” l x 9’7” w x 8’h
1 podcast studio / editing room - 12’4” l x 9’9”w x 8’h
1 closet for storage / mechanical - 11’6” l x 3’7” w x ?h

3 - ROOM LAYOUT.png

I have worked these room dimensions using the Amroc room mode calculator to have the ratio fall within or close to the bolt area. Here are the projected room modes for Control Room, Booth, and Live Room.

The control rooms are designed to be comfortable monitoring and mixing environments for 3-5 people. The booths are designed to be relaxing vocal recording environments for one person at a time. The live room is designed to be a multi purpose recording room for anything that can’t occur in the booth and it will be shared between the two adjacent control rooms. I expect the primary use of this space to be for recording acoustic instruments, brass, percussion; the filming of “BTS” and “Making of” videos, and the occasional drum tracking session. I’m fully aware that isolation between a 110db drummer in the live room and whispering vocalist in the adjacent booth may not be possible, and this can be addressed through scheduling in the worst case. The podcast / editing room is designed with a lightweight recording and editing rig and a table set up for 6-8 channels of simultaneous vocal recording.

5 - ROOMS DETAIL 1.png

6 - ROOMS DETAIL 2.png

7 - ROOMS DETAIL 3.png

8 - ROOMS DETAIL 4.png

-Isolation

In the genres of music this space is designed for (Hip-Hop, electronic, pop), we are dealing with significant low frequency energy in the monitoring environments. I have measured my personal monitoring levels between 80 and 90db (c weighted, slow), however some less safety-inclined clients (artists and engineers both) are guaranteed to push the levels beyond 100db during playback. The ambient SPL in the existing empty space has been measured at ~55db (c weighted, slow). I’m using a Galaxy CM-130 for these measurements. I have interpreted this to mean we are aiming for over 60db TL in our wall and ceiling assemblies.

To achieve this, I plan to implement a fully decoupled 2 leaf MSM system consisting of 2 layers of 5/8” drywall with green glue between, mounted on 2x4 framing with a 4” air gap between stud faces. Both the stud bays and air gap between frames will be filled with the appropriate insulation. Greg’s TL calculator indicates this system will isolate in excess of 60db over 50hz and approximately 75db of TL from 200hz up. I’ll use the same construction for the inner leaf ceilings.

10 - DETAIL-WALL FRAMING.png

11 - DETAIL-CEILINGS.png

For the floors, I’m planning to lay either 1” 703 or thick carpet padding on the concrete, followed by one layer of OSB sub floor, and finished with vinyl plank flooring. The exact dimensions of these materials will be integrated into my sketch-up model once materials have been specified. Open to any recommendations on this front.

12 - DETAIL-FLOORS.png

I have also designed a modified of the Gervais "Super Door" that consists of a 1 3/4” door slab with a 1” sheet of plywood and a 3/4” sheet of MDF layered on the cavity side of the door. The booth/cr doors also include a 1/2” thick laminated glass window. I have a parts / vendor list that totals $600 USD without the window or about $800 USD with the window. Happy to share the SKP file or components sheet with anyone interested.

13 - DOOR DETAIL 1.png

14 - DOOR DETAIL 2.png

15 - DOOR DETAIL 3.png

-HVAC

It has come as no surprise to me that the HVAC design has quickly become the most challenging part of this process. It seems like I should get a qualified mechanical engineer involved, though I would like to have a detailed understanding of the process to be able to properly interface with them and present them with some ideas for them to refine. My HVAC calculations can be reviewed in the spreadsheet linked directly below. I would love another set of eyes on them to confirm that I haven’t grossly underestimated my requirements. Assuming I’ve done this correctly, I will happily share a blank version of this calculator.

HERE ARE MY HVAC CALCULATIONS

I have split the space into 4 zones, each with a ducted split AHU. I’m locked into using a specific model (Mitsubishi SEZ-KD09NA4) as 3 of 4 have already been purchased, however my reading into these units makes me believe that they are well suited for our purpose of heating, cooling, and dehumidification. I’m working to design a fresh air system that will work in harmony with these ducted split AHU units, though I have some questions about integrating these two systems in my questions section. The silencers in my model are rough sketches, which will be designed in detail once I’ve confirmed my airflow requirements are accurate.

9 - HVAC LAYOUT.png

##QUESTIONS

?Room dimensions:
Does the mathematical relationship of my room dimensions pose a problem? I realize that some of my dimensions are close to being exact doubles of another, though I have offset them by 6 inches to compensate for this. Are room mode calculations more or less important than some dimensions being close to half or double another?

?Walls:
What type of insulation should I use for the stud bays and air-gaps? Roxul Safe-and-Sound seems like a solid choice, however we’re talking about large volumes of this material for the whole project and if I could use something cheaper that would definitely be preferred. Would fluffy fiberglass be acceptable?

?Soffits:
In the current rough sketch of my soffits, my speakers are positioned on the corner lines of the wall intersections which I understand is not ideal, however that’s the only area that I could find enough depth for speaker cabinets. I also realize that as I start to properly frame them out to be massive and rigid, space will become very tight in the corners of my control rooms. I’m leaning towards abandoning the soffits and designing/purchasing desks with integrated speaker stands on the bridge. Are my rooms too small to attempt proper soffit mounting?

16 - SOFFIT SKETCH.png

?Doors:
I recall Gervais’ book stating that TL is not significantly compromised by a single door frame connecting two isolated wall assemblies, but I personally find this hard to believe. I’m prepared to use two doors as designed, but the answer to this has a serious effect on my usable floor space and budget. The modified “super doors” I’ve designed will cost approximately $600 USD each. Do I definitely need two doors for door opening?

?Ceiling:
The ceiling of each recording/listening space is designed with an isolated ceiling structure attached only to the walls of that room with 2 layers 5/8” drywall and green glue between. The plan is to frame this with sistered 2x4 joists due to height restrictions. The maximum span of any ceiling joist will be 10’. The ceilings in question are red in the ceilings photo below. Do I need to maintain this same ceiling construction over our lounge and hallway spaces or could I get away with one sheet 5/8” and less insulation above the common spaces?

4 - CEILING LAYOUT.png

HVAC air handlers will be between the inner leaf and outer leaf ceilings. The models that will be used (Mitsubishi SEZ-KD09NA4) are reported to produce 30db noise when on high, however one leaf of the ceiling system should provide 32.93 db TL. I’m hoping this means I won’t hear my air handlers in the studio spaces despite them being located between the inner and outer leaves – is this correct?

?HVAC:

I’d like to use the same ducting for the AC and the fresh air system. I haven’t yet decided between using an HRV/ERV system or simple exhaust and intake fans; my concern being the physical space occupied by the HRV system. The reading that I've done here recommends placing both the stale air exhaust and fresh air intake on the return air trunk before the air handler so that the fresh air is filtered, dehumidified, and cooled before entering the environment. My tight ceiling clearances beneath existing structural steel may require the use of either 6” or 8” flex duct. Is there a way to avoid using this flex duct?

If we do use flex duct, I’m not sure how we would join the fresh-air system ducting inline. My current thought is to have a separate stale air exhaust port on my return silencers, adjacent to the one that is connected to the AHU. This exhaust would work in conjunction with the fresh air supply line mixing into the system at the intake plenum of the AHUs. If I have described this well enough to communicate my idea - would this be workable?





I realize that I have just laid out a ton of information here, and reviewing it may take some time. My questions are based on my current design, however I expect there are several questions I am not even aware I should be asking. I hope that if any of my plans are misguided you will be able to get me back on track, and I eagerly await the forums input!

Sincerely,
Dylan

[Soundman2020]

Hi there Dylan, and Welcome!

Wow! Great first post... I'll take a little while to work through that, then respond more intelligently...

- Stuart -

[Soundman2020]

Through reading many design and build posts here, it has become very clear to me that the earlier you all are consulted on design considerations, the less headache exists for all involved.

Very true! Don't shoot yourself in the foot by locking anything in too early...

The existing floor is a relatively thick concrete slab (my guess is 12” or thicker) with a basement below.

Nothing going on down there? No offices, bathrooms, etc. where people might be? And conversely: nothing noisy down there? Pumps, fans, furnace, water pipes, etc.

##DESIGN

Your basic layout looks fine, except for the storage area. You are missing one wall across there, directly above CR #1.

I have worked these room dimensions using the Amroc room mode calculator to have the ratio fall within or close to the bolt area. Here are the projected room modes for Control Room, Booth, and Live Room.

Room ratios are only really applicable to control rooms. Not needed for booths or live rooms. I would suggest making your live room larger. I can see a couple of ways of doing that.

Also, for the doors between rooms (especially into the booths), I would consider sliding glass doors, rather than hinged doors. Like this:

BRAUS-0265-CR-to-ISO.JPG

BRAUS-0266-Iso-booth-to-CR-SML.JPG

That's a view each way, from the CR to the booth, then form the booth back to the CR. (Home studio in Australia).

Your soffits need some work too! I do realize that they are just stand-is right now, so no problem.

this system will isolate in excess of 60db over 50hz and approximately 75db of TL from 200hz up.

I'd take that with a grain of salt. Calculators assume perfect conditions, perfect materials, and perfect construction. Real-life is not so perfect. Simple calculators don't take all factors into account, either. I doubt you would see anything close to 60 dB at 50 Hz, nor 75 dB total.

11 - DETAIL-CEILINGS.png

What are those two little "notches" on top of the drywall on the walls?

For the floors, I’m planning to lay either 1” 703 or thick carpet padding on the concrete,

Insulation, definite. Carpet won't work very well for that. You are attempting to do a "drum riser" type floor, so do it like a drum riser!

followed by one layer of OSB sub floor,

One layer won't be enough. You don't want to have a "springy" floor. Go with at least two layers of 3/4" structural plywood, screwed and glued.

DOORS:

Here's how I normally do doors for high isolation: (The series is fairly self-explanatory):

Site-built-door--BRAUS--102+--door-blank-cut.jpg

Site-built-door--BRAUS--105--dropdown-seal-closeup-with-all-layers.jpg

Site-built-door--BRAUS--106+--all-layers.jpg

Site-built-door--BRAUS--107--frames-braced-and-taped-on-floor.JPG

Site-built-door--BRAUS--108--frames-presented-to-rough-opening.JPG

Site-built-door--BRAUS--112+--inner-door-hung.jpg

Site-built-door--BRAUS--113--both-open-hinges.JPG

Site-built-door--BRAUS--114+--both-open-seals-and-gap.JPG

Site-built-door--BRAUS--115+--Finished-Entry-door-from-outside.jpg

Site-built-door--BRAUS--117+--both-open-from-outside.JPG

For high isolation, seals are critical. There' are three independent full-perimeter seals on each of those doors. I designed those for a home studio where the owner teaches drums, and his neighbor's front door is just a few meters away from the studio... With that setup, the neighbor never hears a single thing, even with a full rock band and TWO drum kits going full blast.

It has come as no surprise to me that the HVAC design has quickly become the most challenging part of this process.

Yup!

I have split the space into 4 zones, each with a ducted split AHU. I’m locked into using a specific model

It might be better (and cheaper) to go with one single, large unit that coves the entire studio... or maybe two units. Four seems like over-kill, and rather expensive.

Does the mathematical relationship of my room dimensions pose a problem? I realize that some of my dimensions are close to being exact doubles of another, though I have offset them by 6 inches to compensate for this. Are room mode calculations more or less important than some dimensions being close to half or double another?

If you put those dimensions into Amroc and Bob Golds calculator, and got good results (no fails on the BBC tests, good Bonello curve, close to or inside the Bolt area, etc.) then you should be OK.

What type of insulation should I use for the stud bays and air-gaps? Roxul Safe-and-Sound seems like a solid choice, however we’re talking about large volumes of this material for the whole project and if I could use something cheaper that would definitely be preferred. Would fluffy fiberglass be acceptable?

Most mineral wool with a density of around 50 kg/m3 would work, as would most fiber-glass insulation with a density of around 30 kg/m3.

I’m leaning towards abandoning the soffits

Bad idea! Flush-mounting your speakers in "soffits" is the single most important, best, thing you can do for room acoustics. If you want your studio to stand out among the competition, then soffit-mount is a must

and designing/purchasing desks with integrated speaker stands on the bridge.

Even worse idea! Never, ever put speakers on the desk, never, ever have a desk with any shelves, panels,racks, pillars or anything else that rises above the surface. It there's one good way of messing up mix position, then putting in a big desk with speakers on shelves, is it. Guaranteed to down-grade the acoustic response at the mix position, regardless of what else you do to the room.

Your soffits can be fixed to fit in well with that room. I have designed much, much smaller rooms with soffits, successfully. There is plenty of space, if you use it well.

Are my rooms too small to attempt proper soffit mounting?

Is this room too small to attempt soffit mounting?

BDNY--full-room-from-door.JPG

That's it. You are seeing the entire room there. Total floor area is 9 m2...

There is room: you just need to design the soffits carefully to use it intelligently.

I recall Gervais’ book stating that TL is not significantly compromised by a single door frame connecting two isolated wall assemblies, but I personally find this hard to believe. I’m prepared to use two doors as designed, but the answer to this has a serious effect on my usable floor space and budget.

I always use two doors, back-to-back. Always. The more isolation you need, then heavier the doors need to be, and the larger the gap needs to be.

The ceilings in question are red in the ceilings photo below. Do I need to maintain this same ceiling construction over our lounge and hallway spaces or could I get away with one sheet 5/8” and less insulation above the common spaces?

Those are outside of the isolated area of the studio, so you can do whatever you want for that area. You could even leave it open up to the roof, if you wanted. As long as your shell around the isolate area is complete, 100% sealed, same mass all around, then there's no reason to worry about the non-isolate area.

HVAC air handlers will be between the inner leaf and outer leaf ceilings.

Bad idea! AHU's need servicing, maintenance. cleaning, repair, replacement. You don't want to be knocking holes in your isolation leaves to get at them. Put the AHU's out in the non-isolated area, or even in a utility room if they are too noisy. Only your silencers and ducts can go in the cavity between the leaves.

I’d like to use the same ducting for the AC and the fresh air system.

If you are using AHU's, that's the ONLY way to do it. Otherwise you'd need twice as many silencers (eight for each room....), and twice as many ducts... and you'd end up with less isolation, and a headache!

Hopefully that gets you on the right track!

- Stuart -

[Dylanmcdougle]

Stuart,

Thank you so much for your very prompt and detailed reply! Naturally, your answers have spurred more questions which I will gather and articulate as concisely as possible. Your time is much appreciated.

Dylan