John Sayers' Recording Studio Design Forum Archive

Hi all,

First of all let me thank you all for sharing so much info. I have been a silent lurker for a while, and i have learned a lot here!
I am an amateur/hobbyist "recording engineer", and i have now bought a house that will let me have my own "semi-Pro" studio.

I'm thinking about building a nice and comfortable mixing room, and a small recording booth that will allow me to record acoustic drums, guitars etc.
Regarding noise and neighbors, i don't have many concerns because its an isolated house. However the recording booth is meant to be in a room where there is a window outside.. However i'm thinking on building a "room inside a room" type, so i don't think there will be much leakage outside.
The house is made of bricks and concrete, and the place where the studio is being build is in the basement which is completely underground on one side.
Budget wise i have no constraints for now.

I have done some blueprints on sketchup of what i think will work for me... However i have no idea if this is the best approach on space utilization. The rest of the empty space is hard to negotiate with my wife But i am open to suggestions about a better layout or disposition.

blueprints: https://dl.dropboxusercontent.com/u/9925419/piso-1.skp

Hope you guys can give some advice on this project of mine.
A big big thank you in advance!

Pedro

Hi again, I had read the rules before posting, and i have not included measures of the room in the post because the sketchup model i made is precise and has the real measures of the available spaces.

The rooms heigh is 2.8m

I can see that i will have issues with the recording room since its a square, i was thinking on making a oblique roof to try and mitigate the almost equal sizes of all walls.


Again, thank you

Hi there Pedro, and Welcome!

Regarding noise and neighbors, i don't have many concerns because its an isolated house.

OK, but what about noise in the house itself? For example, other people walking around, doors opening and closing, toilet flushing, phone ringing, TV, radio, vacuum cleaner, ... also things outside, like thunder, rain, wind, helicopters, sirens, etc. There are lots of sounds that could mess up your recording sessions. And going the other way, too: sounds from your studio could disturb other people in the house...

However the recording booth is meant to be in a room where there is a window outside.. However i'm thinking on building a "room inside a room" type, so i don't think there will be much leakage outside.

If there is a typical house window, then that will need replacing. That's a very weak point for isolation. You'll need to replace that with a single, fixed, sealed pane of thick laminated glass, then put another similar pane of glass in the inner-leaf.

However i have no idea if this is the best approach on space utilization.

It looks like a good layout to me. Are all of those walls already built down there?

I can see that i will have issues with the recording room since its a square,

Yes, but you can move one of your walls a bit to fix that.

I'm wondering why you have the door at an angle on that room? Wouldn't it be better to have it line up with the other door, that leads into the control room? There's no need for that wedge-shaped space between the two doors: they can be parallel, with no problem.

i was thinking on making a oblique roof to try and mitigate the almost equal sizes of all walls.

That won't help: the problem is with the walls, not the ceiling. It is the axial modes in the length and width directions of the room that will be aligned, not the ones in the height direction. You would have to change the position of one of the walls to fix that. Also, it's not a good idea to lower the ceiling in a track room, especially if you will be tracking drums in there. Ceiling height is good, acoustically: with drums, for example, you normally have a pair of overhead mics,. and with a low ceiling those are very close to it, so you get artifacts caused by the reflections. High ceilings are good, so try to keep it as high as you can.

- Stuart -

Soundman2020 wrote:Hi there Pedro, and Welcome!

Thank you!

Regarding noise and neighbors, i don't have many concerns because its an isolated house.

OK, but what about noise in the house itself? For example, other people walking around, doors opening and closing, toilet flushing, phone ringing, TV, radio, vacuum cleaner, ... also things outside, like thunder, rain, wind, helicopters, sirens, etc. There are lots of sounds that could mess up your recording sessions. And going the other way, too: sounds from your studio could disturb other people in the house...

I may have some issues with toilet flushing because the recording room is beneath a wc. People walking around and the rest (phone, vacuum etc) i don't think will be an issue. Outside noises, maybe thunder. Cars and sirens i doubt will be an issue since the house is located on a very quiet hill. And since the room is almost completely beneath the ground it will not suffer much from those if i do things right with the window isolation i think.

However the recording booth is meant to be in a room where there is a window outside.. However i'm thinking on building a "room inside a room" type, so i don't think there will be much leakage outside.

If there is a typical house window, then that will need replacing. That's a very weak point for isolation. You'll need to replace that with a single, fixed, sealed pane of thick laminated glass, then put another similar pane of glass in the inner-leaf.

I will probably maintain the existing window, but add a sealed pane (like you suggested) inside with double glass (one of them slightly tilted) and about 5 cm (or more if possible) of air box. Do you think this will work? If i remove the existing window it will mess a bit the house aesthetics outside.

I am also thinking in adding a similar window to the plasterboard recording room (the room inside the room) in order to have natural light there. Do you think adding a sealed glass panel to the plasterboard wall will have a big impact on the isolation?

However i have no idea if this is the best approach on space utilization.

It looks like a good layout to me. Are all of those walls already built down there?

Most of them yes. The only one missing is the bottom one where the entrance to the mixing room is located. That one will also be made of bricks and concrete.

I can see that i will have issues with the recording room since its a square,

Yes, but you can move one of your walls a bit to fix that.

I'm wondering why you have the door at an angle on that room? Wouldn't it be better to have it line up with the other door, that leads into the control room? There's no need for that wedge-shaped space between the two doors: they can be parallel, with no problem.

I change the layout and tilted the walls a bit. I attached the new layout below. Do you think it will work?
I have that angle because otherwise i would not be able to have the double door aligned. By constructing the platerboard room inside the recording room i could not align the two doors since the wall that divides the laundry from the recording room is already built. I don't know if i explained myself well, but i can try and make a sketch to better describe the issue if needed

i was thinking on making a oblique roof to try and mitigate the almost equal sizes of all walls.

That won't help: the problem is with the walls, not the ceiling. It is the axial modes in the length and width directions of the room that will be aligned, not the ones in the height direction. You would have to change the position of one of the walls to fix that. Also, it's not a good idea to lower the ceiling in a track room, especially if you will be tracking drums in there. Ceiling height is good, acoustically: with drums, for example, you normally have a pair of overhead mics,. and with a low ceiling those are very close to it, so you get artifacts caused by the reflections. High ceilings are good, so try to keep it as high as you can.

- Stuart -

Changed the wall like you suggested!
Also regarding the overall measurements of the mixing room, do you think they will be ok in terms of acoustics? Regarding modes, standing waves issues etc?

Thank you very much!!
Pedro

Any opinions?

I may have some issues with toilet flushing because the recording room is beneath a wc. People walking around and the rest (phone, vacuum etc) i don't think will be an issue. Outside noises, maybe thunder. Cars and sirens i doubt will be an issue since the house is located on a very quiet hill. And since the room is almost completely beneath the ground it will not suffer much from those if i do things right with the window isolation i think.

It sounds like the toilet and water noise will be your biggest problems then. If you are right under the bathroom, then you will need to figure out a way to exclude all the plumbing from the MSM cavity: it has to be outside your outer leaf.

I will probably maintain the existing window, but add a sealed pane (like you suggested) inside with double glass (one of them slightly tilted). ... and about 5 cm (or more if possible) of air box

There's at least five things wrong with that idea!

1) It would create a 3-leaf system, and therefore you would have WORSE isolation in low frequencies than for the equivalent two leaf system.

2) The existing window likely has very thin float glass, which does not isolate well.

3) The existing window is likely operable (it opens) and therefore has serious sealing issues. Each of your leaves must be as air-tight as you can possibly make it, and operable windows make that impossible.

4) Tilting one of the panes reduces isolation, since it means that the MSM cavity is smaller along one edge, and the resonant frequency is therefore higher than it would have been if the two panes were parallel.

5) A 5cm gap is way too small: the MSM resonant frequency would be too high, so once again your low-frequency isolation would be poor.

If you wanted to retain the exterior window for aesthetic purposes, you'd need to put a very thick pane of laminated glass in the same frame, as far away as you can get (along with a suitable desiccant), then leave a large air gap and put another very thick laminated pane in your inner-leaf. The thickness of the panes and the size of the air gap between them an be calculated using the equations for isolation, based on how much isolation you need, and the construction of the walls.

I am also thinking in adding a similar window to the plasterboard recording room (the room inside the room) in order to have natural light there. Do you think adding a sealed glass panel to the plasterboard wall will have a big impact on the isolation?

Yes. Commercial double-glazed units are no use for studios, since they don't have good isolation characteristics for low frequencies: However, if you want a window in there between the rooms, there's no problem at all in doing that. It simply has to be done as a proper 2-leaf MSM system: only 2 leaves, with a large air gap between them, ans sufficient mass on each leaf to get the isolation level you want.

I change the layout and tilted the walls a bit. I attached the new layout below. Do you think it will work?

The front of the room is looking better but you have not created a proper 2-leaf system there, and the back of the room should never narrow down again: it should either get wider behind the mix position, or stay the same width. Narrowing it down creates a compression wall, which is not a good idea. You are "focusing" low frequency tones towards the back wall (where they are already a problem), and forcing an increase in intensity if the width if the cross-section of the room gets narrower.

I have that angle because otherwise i would not be able to have the double door aligned.

I'm not sure I understand... Why is that? Maybe you could model the actual doors in there, and show why it would not be possible to line them up?

I don't know if i explained myself well, but i can try and make a sketch to better describe the issue if needed

That would be good! You'll need to model those doors and all the associated framing anyway as part of your basic design (so that you can get into the detailed design later), so it won't be wasted effort!

Changed the wall like you suggested!

I guess I didn't explain myself very well! You do not need to splay your walls: all you need to do is to move one of the walls so the dimensions give you better modal response. The walls can be left parallel with no problem. I you splay them as you are showing now, you are just wasting space for no real acoustic benefit.

Also regarding the overall measurements of the mixing room, do you think they will be ok in terms of acoustics? Regarding modes, standing waves issues etc?

Room modes ARE standing waves! You can calculate all of that using one of the many room mode calculators. Use one of these Room Ratio calculators to figure out the best dimensions for your room:
http://www.bobgolds.com/Mode/RoomModes.htm

http://amroc.andymel.eu/

Both of those are very good, and will help you to decide how best to build your room.


- Stuart -

Thanks for all the tips and advice, i will review my sketches and post a revised version as soon as possible!

First of all, sorry for not updating the topic for so long, but i have been doing some construction work on the house and as such this project got little attention.
However after thinking hard about all the issues you exposed and looking again at the blueprints and the actual house i have changed the whole layout. And i think for the better.

I have moved the live room to another part of the basement, it now has no windows, its not beneath the bathroom, and two of the walls are beneath the ground so no sound leakage or neighbours to worry about. The only problem will be leakage of sound to, and from the house. I hope building a double leaf system will improve on that having the interior room completely decoupled from the outer walls. Do you think this is the way to go?

For the actual studio, i have decided to go with a RFZ design. i'm going to soffit mount the speakers on 30º bass traps, create some helmotz resonators on the walls using 6º angle, and build two big bass traps on the end corners followed by a big absortion wall in the middle. The room ratios are very close to 1:1.4:1.9, with only the celling being a little higher than needed, but since this is an rfz design it should not matter very much right? Also i've ran the numbers on the simulators you guys recomend and i think the numbers are good (lots of green stuff )

The problem with this design is that both rooms are apart, so in order to record someone i will need some kind of video camera or something. The whole cable part wont be a big issue since i can easily send a tube between both rooms.

I have attached some pics of the whole thing. Sorry for the simple sketch on the studio but i did not have time to elaborate further.

Thank you for all the help!

Hi all again.. I've been reading a lot and learning a bit more about Rfz, and redesigned the control room.
I know the theory behind the RFZ design, but designing an effective studio is a completly diffente ballpark..
I did some ray tracing to see the reflections and i think it looks ok on that departament, but i could really use your advice since i'm sailing tough waters here
Also the back of the room will consist of two very big basstrap/fullrange absorbers, and even the door will have a respectable absortion panel attached to it.

The questions are:
Is this design acceptable?
What things would you guys change?
Regarding acoustic treatment, what more would you guys add?
Would adding some helmotz resonators on the room mode frequencies help tame some undiserable bass "spikes"? (wild guess)

Again, thank you for all the help you can give me!

ps:the cylinder in the center represents where my head will be.

Anyone?

I did some ray tracing to see the reflections and i think it looks ok on that departament, ... Is this design acceptable?

You didn't show your ray-tracing, so it's hard to say! But to me, it looks like you still have first reflection issues...

Also, you seem to be tilting your front walls... is that really needed? That's hard to build...

Regarding acoustic treatment, what more would you guys add?

What do you have already? You only mention large bass traps on the rear wall, but don't provide any details of that, so it's hard to say what the effect would be, or what else you would need.

Would adding some helmotz resonators on the room mode frequencies help tame some undiserable bass "spikes"?

Probably not. Helmholtz resonators are hard to tune anyway, and it's even harder to get them to work down to modal frequencies. Even if you could, placing them correctly would be a bitch: and they would have to be huge!

- Stuart -

Wonderfully built...

Hi all, sorry for the late reply.. was actually moving inside the new house and having to deal with all the chaos it implies.

thank you for the answer.
I did the ray casting by hand on google sketchup but i deleted the lines because it was a mess. sorry.
Anyway i ill simplify the design and abandon the tilted walls. Makes things easier.
The bass traps i still have to build them, so part of the question was if you guys had any advice on that. Would hangers be a good idea? or shoudl i go with the standard ones applying soft rockwool inside them?
Should i build two "John sayers" slated bass traps to complement the front bass traps?
Once i have more time i will post some more sketches here and once i start build i will document the process.

Thank you all for the kind words

so part of the question was if you guys had any advice on that. Would hangers be a good idea? or shoudl i go with the standard ones applying soft rockwool inside them?

The best, most effective ones are "superchunk" style bass traps in the corners of the room. You make those by cutting full panels of OC-703 insulation into large triangles (24" along the sides), and stacking those in the corners, floor to ceiling. Then you make a light frame to go vier that and cover it in fabric, to look good.

- Stuart -

Hi all,

First of all, many appologies for not writing in a long time.. but buying an used house bears its problems.. and i have been caught doing way too much repairs for my taste...
However i have doing my homework when i have free time!

I arrived on the following studio design and skematics.

Blueprint and description: Raytracing: Soffit mount design: Corner bass traps: Front absorver and trap: Rear bass traps: Speaker box: Continues next post due to image upload limitation