John Sayers' Recording Studio Design Forum Archive

So, I've made a layout which has total isolation between all the rooms (except the hallway) and included all of the windows and doors that I could possibly want... it's a hell of a lot.

I do not have to put all of these windows and doors, but it's all the possibilities I can think of. In an ideal world with an unlimited budget, this is how I could do it. It would mean there are good escape routes in each room, good isolation between each recording space and control room, lots of day light (though I do live in Wales... so still not likely) and good overall access to each space. I have to take a look at the fire safety regulations as I know that in the states you cannot have double doors open on to another set of double doors...but I think not having double doors access to the live room will make moving pianos/drums etc in and out a bit more of a challenge. There's also another three things that would suck about having this many doors; 1. the expense 2. it's a lot of doors to open and close 3. no much room in the recording spaces for bass trapping in the corners.

This got me thinking... the more I redesign the control room, the more sense it makes for me to build it with inside out walls. Here's why...unlike most builds, I am going to be starting with the inner shell first. The frames are already built and already standing on a concrete slab. I just need to extend the height of the walls on one side and build the new A frames for the ceiling. This is just the control room that I am talking about. Now as I am building it in stages, this inner shell will also be the outer shell for a while until I can afford to build the outer shell. So instead of boarding the internal side of the walls, why don't I just board the external side of the walls and have them inside out thus saving space and having a bit of acoustic treatment already taken care of? I could use 2 layers of water resistant 19mm OSB for the external side of the walls/ceiling (1st stage roof) and put the siding/roofing sheets on top of that for now. Then when it comes to building the outer shell I can just remove the siding and roofing sheets and use them for the outsell shell once it's built. I will just make sure I have a long enough over hang on the roofing sheets to begin with.

I could also build the live room like this which would help out with the lack of bass trapping in the corners due to the doors, though 6" broadband absorbers all round the room is not the same as 3' thick corner traps... as I'll be doing a vaulted ceiling the vaulted part could fit essentially a long corner trap going all throughout the middle of the room. At least in the control room anyway.

Now, if that would work then my only question is what would I be sacrificing in terms of isolation by doing it this way? My original plan was to have non-inside out walls with a 2 inch gap between the inner and outer walls, which would give me an air gap of 12" (the control room frames are only 2x4, so 4+2+6 = 12) but by installing inside out walls for the inner shell it would decrease to 8". BUT that would only be on 3 sides; the hall way side would have a 5'6" air gap and where the control room window is that would be another 2' or so air gap.

What do you guys think?

I'm really enjoying seeing your progress!

I agree that the double door situation will probably not work out. You can custom build doors. You can make a 4' wide door that should suffice for what you need.

Your ISO room doors could be moved to sliding glass doors where you glass is. That would allow you to put a beefy corner trap where the existing doors are (in your live and ISO room).

I really don't think you need escape doors from your ISO room. Yes, it is great for safety, but it's not very far to reach the closest exit doors (where you currently have the double doors). Plus, there is a clear sight line to see if anything tragic was going down across the building. And you're right, whether we like it or not, doors are super expensive, even when we make our own.

Your soffit wing walls (the walls between your soffit and your side walls) currently look like straight walls that have some panels on them. You'll have to ray trace to figure out their angle, but having them straight back like that probably isn't going to work. Not a big deal right now in your building layout stage, but yeah, that is something you'll need to sort out sooner than later.

Your decoupled wall design is looking great other than at the window. Your live room wall looks right, but you will want a straight inner leaf wall across the front of your control room. You'll want some treatment between that drywall and your front wall, similar to the idea you have on your back wall. That's an easy fix.

Building inside out is definitely a great idea.

Assembling your place inner room first is unique and I personally have a mini-stroke trying to imagine how to pull it off. But if you can picture it, I'd suggest framing it up/building it as you propose with SketchUp so you can face the complications of doing so. This will ensure it's possible!

I quite like the design thus far. You need to start drawing it from the ground up now. Instead of just pulling up walls like I did for you before, I suggest drawing real wall studs (using the "x4" or "x12" type feature once you copy/move a component really speeds up that process). Just remember to use the layers (foundation, frost wall framing, frost wall insulation, CR inner leaf framing, CR inner leaf drywall, etc, etc)

Before you frame up your acoustic treatment walls (front wall, soffit walls, soffit wing walls, side walls, etc), you should probably just pull up a rectangle so you can easily rotate it and figure out your ray tracing. THEN frame it.

I'm getting excited for you now as it's coming to fruition.

Greg

***Edit***
I just noticed your wall depths. It looks like your control room is framed with 2x4's and everything else is 2x6". All of your inner leaf walls should be okay to be framed with 2x4s. You should probably talk to a roof truss specialist type person to figure out how exactly you can frame up your inner leaf ceiling such that it retains it's integrity under the load of two layers of 5/8" drywall, dense insulation, lighting, and any other extra type of treatment you may hang off of it.

Also, that made me remember reading your math about wall cavity depth. You implied that a 2x4" will be 4" deep. It is only 3.5" deep actually. A 2x4's real life dimensions are ~1.5"x3.5". And a 2x6 is actually ~1.5"x5.5". Just so you know when drawing it up and/or doing any calculations

Gregwor wrote:I'm really enjoying seeing your progress!

I agree that the double door situation will probably not work out. You can custom build doors. You can make a 4' wide door that should suffice for what you need.

Your ISO room doors could be moved to sliding glass doors where you glass is. That would allow you to put a beefy corner trap where the existing doors are (in your live and ISO room).

I really don't think you need escape doors from your ISO room. Yes, it is great for safety, but it's not very far to reach the closest exit doors (where you currently have the double doors). Plus, there is a clear sight line to see if anything tragic was going down across the building. And you're right, whether we like it or not, doors are super expensive, even when we make our own.

Your soffit wing walls (the walls between your soffit and your side walls) currently look like straight walls that have some panels on them. You'll have to ray trace to figure out their angle, but having them straight back like that probably isn't going to work. Not a big deal right now in your building layout stage, but yeah, that is something you'll need to sort out sooner than later.

Your decoupled wall design is looking great other than at the window. Your live room wall looks right, but you will want a straight inner leaf wall across the front of your control room. You'll want some treatment between that drywall and your front wall, similar to the idea you have on your back wall. That's an easy fix.

Building inside out is definitely a great idea.

Assembling your place inner room first is unique and I personally have a mini-stroke trying to imagine how to pull it off. But if you can picture it, I'd suggest framing it up/building it as you propose with SketchUp so you can face the complications of doing so. This will ensure it's possible!

I quite like the design thus far. You need to start drawing it from the ground up now. Instead of just pulling up walls like I did for you before, I suggest drawing real wall studs (using the "x4" or "x12" type feature once you copy/move a component really speeds up that process). Just remember to use the layers (foundation, frost wall framing, frost wall insulation, CR inner leaf framing, CR inner leaf drywall, etc, etc)

Before you frame up your acoustic treatment walls (front wall, soffit walls, soffit wing walls, side walls, etc), you should probably just pull up a rectangle so you can easily rotate it and figure out your ray tracing. THEN frame it.

I'm getting excited for you now as it's coming to fruition.

Greg

***Edit***
I just noticed your wall depths. It looks like your control room is framed with 2x4's and everything else is 2x6". All of your inner leaf walls should be okay to be framed with 2x4s. You should probably talk to a roof truss specialist type person to figure out how exactly you can frame up your inner leaf ceiling such that it retains it's integrity under the load of two layers of 5/8" drywall, dense insulation, lighting, and any other extra type of treatment you may hang off of it.

Also, that made me remember reading your math about wall cavity depth. You implied that a 2x4" will be 4" deep. It is only 3.5" deep actually. A 2x4's real life dimensions are ~1.5"x3.5". And a 2x6 is actually ~1.5"x5.5". Just so you know when drawing it up and/or doing any calculations

Hey Greg, thanks for your continued support.

haha sliding doors, as soon as I uploaded my last reply I looked at my design and thought the same! So that most recent design was just to show the position of all potential doors and windows, the design that I've uploaded now is more likely what I'll aim towards, with a few final tweaks of course.

The reason for the control room front wall being like that is because this way the window can be part of the baffle. I don't see another way of doing it apart from using 3 pieces of glass (the front wall would be straight with a straight piece of glass, then the acoustic wall would be angled with 3 pieces of angled glass, then the live room wall and glass would stay as they are now). But 3 pieces of glass would be a 3 leaf system right? So please, enlighten me to how I should do it by using a straight wall but angled glass.

BTW, I know that I don't have to have the glass angled, but firstly it looks cool and secondly it gives me a lot more space behind the console. I hate squeezing behind a console to make changes or fix something. I want a nice bit of space to swing a cat there.

Next, angling the side walls. Okay I have designed control rooms with angled side walls only to be told that it just makes it more complicated to predict and treat due to increased modal issues. I've researched the hell out of this and there's still a lot more to be done. Here's what I know so far and please correct me if I am wrong:

Angling the walls can make a difference to side reflections missing your ears and going to the back of the room to be absorbed/diffused, I get that. But two things. Firstly my room is not that wide as it is, if I angle the wings then walking to the side of the console will be very uncomfortable.. I'll have to crawl under it. Secondly it will just make my room even more difficult to predict/treat as the room will no longer be rectangular, now I would have to try and predict all of the different modal issues at all of those different dimensions to the width caused by the angled walls. Not forgetting of course the vaulted ceilings that I already need to deal with. That's complicated! Now if you're talking about angling some panel absorbers then I could come up with something, but angling the walls could cause more problems than it solves. Besides the walls are already built and standing.

It's the same with windows and glass doors... for years people thought that it is necessary to angle windows and glass doors in recording studios, when in fact it's not necessary. It actually decreases the isolation where the two panes are closer. People compensate this by using thicker heavier glass, but the only real reason to angle a window is because you think it looks cool or your window is causing a reflection that needs to be dealt with and since you can't put panel absorbers or diffusion on windows (without obscuring the glass and nullifying the purpose of the window being there) they need to be angled. I will be angling some of the glass in my studio where needed but only for these two reasons. With walls you can treat them, in a controlled and simpler manner.

BTW what software do you use to do ray tracing?

I have started turning my floor plan in to a 3D model, the sight lines are looking good Still got quite a way to go on it though. Thanks for the tip about using 2x4s for the internals, that should save some much needed space.

P.S. Yes sorry about my maths, I know that they are not exactly 4" and 6" I was just being lazy, but should know better!

Hey Greg, thanks for your continued support.

I assure you, it's my absolute pleasure.

But 3 pieces of glass would be a 3 leaf system right? So please, enlighten me to how I should do it by using a straight wall but angled glass.

This answer will tie in with my next answer. Your front wall can be straight, but your acoustic treatment wall can stick out closer to your desk as you have it in your drawing all you want. You can basically just frame in your window, keeping the hole in your wall where the window is, sealed (to maintain your inner leaf integrity). You would only have a a total of 2 pieces of glass. One on your acoustic treatment wall, where the window frame would continue forward and connect to your inner leaf frame. And the other glass on your live room inner leaf frame.

Okay I have designed control rooms with angled side walls only to be told that it just makes it more complicated to predict and treat due to increased modal issues.

Your room will be square, acoustically speaking. Your inner leaf wall of your control room will be framed square just like a normal bedroom would be (except maybe using the inside out technique as you described). The acoustic treatment frame would be the one that is all weirdo shaped. Like your rear wall with hangers in it as you've drawn on your SketchUp ... that's just a wooden frame holding acoustic hangers and then fabric on the front of it. The same with your side walls. Your front wall, soffit, and soffit wings will MOSTLY consist of hard, heavy material such as wood or in some studios, even concrete! These angled walls are there for several purposes. The front half of your room (in front of your ears) will mostly be hard surfaces. The reason I say "mostly" is because the upper part of them will be. The lower section can be used for bass trapping. They're angled and made of hard materials so that they deflect the sound away from your ears and like you said, into the rear wall to be absorbed some. The side walls can be whatever your room needs acoustically. They're often angled so that the treatment devices that go on those side walls cover a more broad chunk of the audio spectrum. If you look in John's recording manual that is linked on his home page, it will show you a helmholtz resonator (on the absorbers page, then on the mid frequencies tab). If that device was angled on the wall, it's depth would vary from one edge to the other. It would linearly change the frequency at which it was tuned to directly proportionally to it's varying depth. The rear wall corners are often splayed out as your SketchUp indicates in order to achieve a deeper cavity. This will allow even lower frequencies to be affected by the treatment. And with any sort of helmholtz treatment in corners, the varying corner depth could be beneficial to you.

for years people thought that it is necessary to angle windows and glass doors in recording studios, when in fact it's not necessary. It actually decreases the isolation where the two panes are closer.

As far as I know, there is some slight benefit to angling two piece of glass, however, like you said, those benefits are maybe outweighed by the increased gap distance between two parallel pieces. I personally will be angling 1 piece of glass for two reasons:
1. Reflection. I want to try and keep any overhead lighting reflections out of my window.
2. If I tilt the top part of the glass towards myself, no dust will ever get on the window.

BTW what software do you use to do ray tracing?

I use SketchUp. But, unless you make each trace a group or component, you can't assign them to layers, and if you draw a line through another line, it cuts it which makes it impossible to manage. I've attached a picture of a close up of one of my traces. Basically, I put a dot at the acoustic axis of my speaker. I then make a circle and type 1/32 for it's size. Then I triple click it, make a group or component, then assign it to a layer. Personally, I tried to keep it more organized by using one speaker to trace shooting to the side walls, and the other speaker shooting across my listening field to the other speaker. I assigned each trace to it's own layer and named them accordingly. Being able to turn each one off before you make your next one was tidy. The pictures I used are from my own design, but they're outdated as I'm on my wife computer here and I don't have current versions on here. Either way, you can see that my acoustic treatment walls are not framed or anything. I was/still kind of am at the stage where I'm solidifying angles. Once that is figured out, I'll drop them down and frame them stud for stud.

I'm falling asleep here so I better get to bed. I hope what I wrote made some sense. I can't think clearly right now so I apologize if it was nonsense. Better to write something rather than leaving you hanging though. That's one of my goals on here is to help keep up on peoples questions so that people aren't left hanging for too long. It's a big job and we all should be very grateful for the pros who have helped people out for the last 15+ years! It's a lot of work. But it's awesome.

Night.

Greg

This answer will tie in with my next answer. Your front wall can be straight, but your acoustic treatment wall can stick out closer to your desk as you have it in your drawing all you want. You can basically just frame in your window, keeping the hole in your wall where the window is, sealed (to maintain your inner leaf integrity). You would only have a a total of 2 pieces of glass. One on your acoustic treatment wall, where the window frame would continue forward and connect to your inner leaf frame. And the other glass on your live room inner leaf frame.

I'm struggling to get my head round this, how will the front wall be sealed if it has a hole in it?

Here, I just threw an inch of MDF in for a visual. It will maintain your seal (once a window is in place of course!) Anyway, that's the general idea.

Ignore all the crap wrong with the images I uploaded. I just wanted to show you how to maintain the leaf mass and keep the seal.

Greg

Gregwor wrote:Here, I just threw an inch of MDF in for a visual. It will maintain your seal (once a window is in place of course!)

Window Sill Extension.jpg

Window Sill Extension Top View.jpg

Window Sill Extension Front View.jpg

Anyway, that's the general idea.

Ignore all the crap wrong with the images I uploaded. I just wanted to show you how to maintain the leaf mass and keep the seal.

Greg

Hey thanks for taking the time to clear that up for me, I see what you mean now though I struggle to see why doing it like that is better than bringing the front wall in and having the window attached directly to the full thickness wall? Seems like the MDF collar would be a weak point in the MAM system?

I struggle to see why doing it like that is better than bringing the front wall in and having the window attached directly to the full thickness wall?

Four reasons to do it the way I suggested:
1. Maintaining a rectangular room will allow you to actually calculate acoustic characteristics of the room.
2. Not chopping into the room will create a larger acoustic space. Only slightly larger, but larger non-the-less.
3. Making the rectangular room will be much easier to build (the ceiling alone would be a bit of a pain to make).
4. And almost more importantly, it will allow you to have deeper cavities for bass trapping along the top and bottom of your acoustic wall (soffit and window). That's the biggest advantage.

Pointing out those benefits, I'd suggest to maybe build your live room wall the same way. This would give you a nice deep pocket to bass trap under the live room window and maybe have a good mass/sealed box to run cabling out of.

Seems like the MDF collar would be a weak point in the MAM system?

Yes, every piece of material will be a bit different, and each manufacturer creates products with different densities, but on average, let me give you these figures:
5/8" fire rated drywall = ~ 2.2 lbs/ft^2
1/2" MDF = ~ 2.5 lbs/ft^2

So if you have 2 layers of 5/8" drywall, you're inner leaf wall will have a mass (surface density) of ~4.4 lbs/ft^2. No different than building your HVAC duct silencer boxes, you will build the window sill extension out of 1" MDF. The mass of that MDF will be ~5 lbs/ft^2. So, no, the MDF will not be the weak point. Depending on your window and the sealing you use, it will probably be the weak link. Having said that, I've never researched how to join pieces of window effectively, but that's something you should find out about and share here on your thread. Try to find out what sort of flexible adhesive they use to join the windows for 3 piece window designs like yours that will have the mass needed to have more than 4.4 lbs/ft^2. If that doesn't exist, then THAT will be the weak point. I'm sure (like backer rod + acoustic caulk, there has to be some sort of product or combination of products that possess those desired properties.

That's great info, you've answered a few questions I've been wondering for years!

Regarding the adhesive between the panes, I only know of studios using a type of clear silicone, so obviously not very heavy but air tight. Considering the massive amount of studios that have wrap around windows I imagine it must work fairly well, at least well enough for them to make thousands of hits and lots of money

The panes obviously have to be cut as perfectly as possible so that they butt up tight against each other. If you check out Kiwi Audio, this is how he did it. His whole build thread is on gearslutz and I've been speaking to him over the past couple of weeks to find out more, though I have not quizzed him on his impressive window yet.

I may end up either using frames around each pane so that I don't need to face trying to seal between the glass, or just go with a straight window. It all depends on budget really, my design is still in it's 'dream' phase One other advantage of having the wrap around window is that it's a lot easier to lift smaller panes of laminated glass than lifting one long and heavy piece! But trying to seal the edges would be a pain.


BTW, regarding the angled wings... if you take a look at the floor layouts for a dozen well known control rooms a lot of them have splayed walls, not treatment but the actual walls. Even in some of Johns designs as well as storyk's designs theres an abundance in wall splaying going on. So it is not out of the ordinary to splay the walls, but it is more unusual to splay the acoustic treatment or resonators it would seem. Having said that, I prefer the idea of splaying the acoustic walls, it makes it a whole load easier for me.

Also, was thinking about building my soffit out of concrete blocks. Poured concrete would be too ambitious for me, but blocks are cheap and rigid. If I didn't build it out of blocks then I would at the very least think about mounting my speakers on concrete block stands which would be coupled directly to the concrete slab. What do you think?

Several issues I see, some of which you already addressed, but some not...
Color code:

BLUE LINES: You are missing a wall here! That's part of your outer-leaf wall, and you do need to complete the envelope.

RED CIRCLES: Because you need to add the wall, you also need to double-up on those doors. Meaning you will have to flip the sense of the one into the LR, which also introduces the issue of a clash with the double doors...

GREEN CIRCLE: Double doors are a problem: It's hard to get a good seal on the vertical joint between them when closed. I'd suggest with going for a larger single door, or maybe sliding glass doors. With a very large single door there's the problem of weight: a massive door that is also very wide puts huge stresses and strains on the hinges, and also on the framing around it. As it opens and closes, it tends to bend and twist the framing, which could eventually lead to sagging, binding, and loss of seal integrity. You need to beef up the framing big-time around large doors, and use several heavy-duty hinges, with long screws that mount deep into the studs.


ORANGE CIRCLES: Do you really need those doors to the outside world? Doors are a potential weak point, and are expensive. Don't put in doors that you don't absolutely need. You have 16 doors in there right now (including the new ones I mentioned above). Even if you manage to build them for just US$ 500 each, that's still eight thousand dollars you are spending on doors alone. I don't know how good your budget is, and maybe 8 grand is not an issue, but if you need to save money, then eliminating those doors would save you at least 2 grand.

I haven't read trough the rest of yoru thread yet, and maybe you already addressed these, but that's what I noticed at first glance on the diagram.

There's also something very weird going on with your soffits that I don't understand at all, so I'll do some reading now, before commenting on that...


- Stuart -

Soundman2020 wrote:Several issues I see, some of which you already addressed, but some not...

WALES-Studio Redesign-problems.png

Color code:

BLUE LINES: You are missing a wall here! That's part of your outer-leaf wall, and you do need to complete the envelope.

RED CIRCLES: Because you need to add the wall, you also need to double-up on those doors. Meaning you will have to flip the sense of the one into the LR, which also introduces the issue of a clash with the double doors...

GREEN CIRCLE: Double doors are a problem: It's hard to get a good seal on the vertical joint between them when closed. I'd suggest with going for a larger single door, or maybe sliding glass doors. With a very large single door there's the problem of weight: a massive door that is also very wide puts huge stresses and strains on the hinges, and also on the framing around it. As it opens and closes, it tends to bend and twist the framing, which could eventually lead to sagging, binding, and loss of seal integrity. You need to beef up the framing big-time around large doors, and use several heavy-duty hinges, with long screws that mount deep into the studs.


ORANGE CIRCLES: Do you really need those doors to the outside world? Doors are a potential weak point, and are expensive. Don't put in doors that you don't absolutely need. You have 16 doors in there right now (including the new ones I mentioned above). Even if you manage to build them for just US$ 500 each, that's still eight thousand dollars you are spending on doors alone. I don't know how good your budget is, and maybe 8 grand is not an issue, but if you need to save money, then eliminating those doors would save you at least 2 grand.

I haven't read trough the rest of yoru thread yet, and maybe you already addressed these, but that's what I noticed at first glance on the diagram.

There's also something very weird going on with your soffits that I don't understand at all, so I'll do some reading now, before commenting on that...


- Stuart -

Hi Stuart, good to have your help - your opinions are extremely valued in my books, so thank you for your help as always.

I've attached my latest design which does fix some of the issues you've mentioned - apart from the extra wall in the hallway. I was wondering if you could you explain to me why this wall is absolutely necessary and why I can't simply use the hallway as my air gap between the two walls? I've seen a lot of studios that are designed like this, though that doesn't say much as there are many with poor design. I just want to know the reason why it's wrong?

The image which you corrected was just to show all the different possibilities of where I could put doors, just to explore my options. The soffit was not complete in that image and since speaking with Greg have adjusted the design - I am fighting between sight lines and speaker placement - your help would be appreciated here.

Thanks again

And here's a layout with a few additional changes.

- added extra wall in the hallway
- all internal walls are now using 4x2s
- removed a few unnecessary windows and doors
- added a bit more length to the live room entrance
- swapped some doors for sliding glass doors
- swapped wrap around window for normal straight window

How's it looking?

How's it looking?

Much better! I'm liking that layout. nice!



- Stuart -

BTW, regarding the angled wings... if you take a look at the floor layouts for a dozen well known control rooms a lot of them have splayed walls, not treatment but the actual walls. Even in some of Johns designs as well as storyk's designs theres an abundance in wall splaying going on. So it is not out of the ordinary to splay the walls, but it is more unusual to splay the acoustic treatment or resonators it would seem. Having said that, I prefer the idea of splaying the acoustic walls, it makes it a whole load easier for me.

It all depends on what you are trying to accomplish! There are reasons for splaying walls, and reasons for splaying treatment... and even reasons for splaying both! Also, when you look at photos of studios, things might not always be the way they look: you might be looking at a surface that looks solid but isn't, or even one that does not look solid, but is! Designers use lots of tricks, both acoustic and visual.

For example, in this studio: None of the room surfaces you see are solid!

- Stuart -