Small studio design

Hi, This is my first post so please forgive/let me know if I miss any information or come across as ignorant. I have a space available to me to design and build a small studio in Alfreton, Derbyshire, U.K. As the building is situated quite close to a busy road so I thought the best way to treat the space would be a floating floor throughout and room within a room construction for the live room? The room is half original house (left portion in the picture below) and half extension (right portion in the picture below) built 30-something years ago. The extension has a wall cavity, so as the cavity can be filled I thought it best to use that space for a live-room with the filled cavity contributing towards the reduction of noise from the road.Another initial thought is that as the front wall has a large single-pane window (See picture below), from prior use being a shop.Would a good idea be to build a wall across the left room, so that both rooms are the same depth, to reduce road noise? (See picture below). I have a budget of around £12k but will have use of beer funded labour. And hopefully have some change left over for a couple of bits of kit. Thanks, Phil.

I've come up with a few designs based on google sketchup files that John has created. The first design (Below) frees up live room space but I'm not sure about the door system I have put in. The second drawing I have gives the control room more width but I will have to ask advise on bringing the listening spot out of the middle of the room to give a bit more seating space. But the access will be improved by having the wall space to fit wider doors and has a bit of storage space in between the corridor and control room doors. The difference in live room size is a reduced width by about half a metre. Any suggestion or advice would be very much appreciated. Thanks, Phil.

Hi Phil. Please read the forum rules for posting (click here). You seem to be missing a couple of things! :) - Stuart -

Hi Stuart, Thanks for the heads up. The location that the studio is being built in shouldn't have any issues with annoying the neighbours as the house is next to a factory one side and the on the other side is my parents house, that is set back quite a way from the building. The floor of the space being used is concrete so I was thinking to have a floating floor to help de-couple the rooms from any vibrations transmitted through the floor, at least.

Just some comments on your design, about things that I happened to notice and about things you said.

shouldn't have any issues with annoying the neighbours as the house is next to a factory one side

OK, great, but how about sound coming the OTHER way? You say you are next to a factory, and also "quite close to a busy road" so there is probably some type of industrial noise that you'd need to isolate, os well as vehicles noise: not just cars going past, but arriving and leaving all the time at the factory, doors slamming, loading / off loading, etc. Plus there are things like wind, rain, thunder, aircraft flying overhead, people talking, lawnmowers, dogs, and a thousand others. Your first order of business should be to determine how much isolation you need (in terms of decibels), then work forwards from there.

The floor of the space being used is concrete

Excellent! Best possible floor you can have.

I was thinking to have a floating floor to help de-couple the rooms from any vibrations transmitted through the floor, at least.

You didn't mention if this is a ground floor build? If so, then that concrete slab is on the ground, with nothing else in between, so you have great isolation and great damping. I certainly hope so, since you don't have enough budget to float your floors properly and also build the rest of the studio! Floating a floor is a big undertaking, very expensive, and hard to get right. You might want to read these threads before you make a decision on "to float, or not to float": viewtopic.php?f=2&t=8173 viewtopic.php?f=2&t=8134 viewtopic.php?t=8135) If you want more technical details on various ways of floating floors and how they actually perform when tested in laboratories, then this is a good place to start: http://www.nrc-cnrc.gc.ca/obj/irc/doc/p ... /ir802.pdf

The extension has a wall cavity, so as the cavity can be filled I thought it best to use that space for a live-room with the filled cavity contributing towards the reduction of noise from the road.

Depends on what you mean by "cavity wall", and how that wall is built. If the two leaves are fully decoupled, then that could be an option. However, isolation is an "all or nothing" proposition: you cannot isolate a room by only dealing with one wall on one side. The entire room has to be isolated, all four walls, ceiling, windows, doors, HVAC system, and electrical system. All of those are part of the isolation plan, and all need to be taken into account. The total isolation is only as good as the weakest link. You can have the best isolated studio in the world, but when you open the door, you no longer have any isolation at all! So it is important to start thinking of your studio as a "whole", rather than a bunch of parts.

Another initial thought is that as the front wall has a large single-pane window (See picture below), from prior use being a shop.

It might be possible to incorporate that into the design, if you want. For example, if you like the view out that window, or if you like natural light. If not, then take out the glass and brick it up.

Would a good idea be to build a wall across the left room, so that both rooms are the same depth, to reduce road noise?

I¿m not sure I understand: Why would having identical dimensions reduce road noise? Isolation depends on mass and air-tight seals, not on room dimensions.

have to ask advise on bringing the listening spot out of the middle of the room to give a bit more seating space

Seating space is not the issue: Acoustics is the issue. The geometric center of the room is the worst possible location for listening, since ALL of the room modes are at either their maximum peak or lowest null right there. So you HAVE to get your head out of that spot, if you hope to produce good mixes that translate well. Theoretically, the least objectionable spot from the modal response point of view, is at 38% of the room depth (38% of the distance between the front wall and rear wall). That's where your ears should be, roughly. Also with that design, you have no rear wall! The entire rear of the control room is a glass door into the LR, so you have no place to put your rear absorption, yet you seem to be using RFZ as the basis for your design, so it is critical to have deep, thick absorption on the rear wall. Hope that helps! - Stuart -

Hi Stuart, thanks for the reply. Yes the space is on the ground floor, should have mentioned that :S sorry. The road is the main issue, the factory specialises in re-ferbishing and selling industrial compressors so I haven't had any noise issues from when I used to live their (over a 24 year period). Anyway, like you say it's all the other environmental noises that I need to deal with as well. As for the designs I think that the layout that will be best suited to me would be the first design, the one that gives the most amount of live room space. Regarding the window, it faces, and also is the closest wall to, the road. So I wouldn't be keen to incorporate it, also from a privacy and security point-of-view. Thats why I thought that creating a "corridor" from the main door across to the lounge door (See attachment below) would provide the opportunity for privacy, a bit more security and the wall providing a solid mass while keeping the window. One thing I did think of is reducing the size of the window then fitting glass blocks to let some light in, what would your thoughts be on the use of glass blocks? I hear their STC rating is pretty high as a unit. One issue I can see is the door being directly in the centre of the rear control room wall. (See below) as I'm not sure the door design shown in the initial design would give enough access space due to the angles involved.

Ground floor: Excellent! So your slab is damped by the entire planet: Hard to beat that! :)

The road is the main issue,

Any heavy trucks that cause the ground to vibrate? Can you feel vibration in your slab when a truck goes past? Or is it just air-borne noise that is bothering you? If there is no vibration, then you'll probably be fine with a "traditional" build: Don't float the floor for all the reasons mentioned in those links, and just build your "room-in-a-room" on top of that slab, complete with new ceiling. Actually, it will be two rooms, each with its own ceiling: CR plus LR.

what would your thoughts be on the use of glass blocks?

Glass blocks should work well as one leaf of a two-leaf system. They have plenty of mass, so as long as you seal them in place well, that would work.

I hear their STC rating is pretty high as a unit.

Yes, but STC is not a good way of measuring isolation for a studio. It does not take into account low frequencies. Even so, glass blocks should be good.

One issue I can see is the door being directly in the centre of the rear control room wall.

That's fine. The door will be opening into the room, so you can have treatment on it; The only issue is it takes up space at the back where you might have wanted to put a sofa or something, but acoustically it is fine to have the door there. - Stuart -

Hi Stuart, Their is a bus stop on the opposite side of the road, and those big diesel engines cause some vibration through the floor when they stop to pick up people. I was thinking about making a wooden floating floor described in John's Recording Manuel. Or cutting down the bus stop sign. In regards to the back wall, would it be a straight case of thick absorption like you recommend. Or would something like a schroeder diffuser work to a similar level? Or is the RFZ design of the room tailored towards absorption? Thanks again Stuart, your input is greatly appreciated.

Their is a bus stop on the opposite side of the road, and those big diesel engines cause some vibration through the floor when they stop to pick up people.

OK, then you do have a problem! One cheapo solution might be to arrange your recording sessions around the bus schedule! But if that is a frequent issue, and interferes heavily with your recording, then you might have no choice but to greatly increase your budget and build a proper floating floor.

I was thinking about making a wooden floating floor described in John's Recording Manuel. Or cutting down the bus stop sign.

Option B sounds like the best one to me! And place a new sign at the end of street: "Compulsory bus detour", with a large arrow pointing the other way... :) Seriously, that kind of wooden deck is not going to accomplish what you want. Take a close look at this: viewtopic.php?f=2&t=8173

In regards to the back wall, would it be a straight case of thick absorption like you recommend. Or would something like a schroeder diffuser work to a similar level?

I would just go with thick absorption, perhaps angled, and perhaps leaving a gap between it and the wall. The room is too small to be able to use any diffuser based on number sequences. Since the operate in both the time domain and spatial domain, they all produce "lobes" around them that need space to smooth over and even out again. Small rooms don't have enough space. A fact that the manufacturers of such devices frequently neglect to mention... Diffusers are only appropriate for large rooms, where there can be enough distance between the devise and your ears for the lobes to merge.

Or is the RFZ design of the room tailored towards absorption?

Part of the original idea with RFZ was that no reflection would arrive at your ears within 20ms of the direct sound, and even then would do so at -20dB down. It's hard to cut 20 dB off the level with a reflector or diffuser! Even with absorption it is a tall order, but with a combination of careful angling, distance and absorption, it can be done, or at least you can get close. - Stuart -

Is it worth buying something like a contact mic/something similar I have not heard of, to measure the vibration through the floor. As the floor only have carpet tiles then the concrete in the space, I just lifted one of the tiles and put my ear to the floor and thought I could hear some noise. Maybe I should conduct a more scientific test before factoring in the cost of full floating floor. In regards to the angling of the absorbers would that be using angles of 6 degrees on the back wall, with the angle towards the walls. Heres a screen-shot as I don't think that was a very good description:

Is it worth buying something like a contact mic/something similar I have not heard of, to measure the vibration through the floor. As the floor only have carpet tiles then the concrete in the space, I just lifted one of the tiles and put my ear to the floor and thought I could hear some noise. Maybe I should conduct a more scientific test before factoring in the cost of full floating floor.

One simple / cheap method is to borrow a stethoscope from a doctor / nurse friend, and use that to listen to the floor and walls. If that leads you to suspect that you do have a problem, then a contact mic hooked up to your DAW could help reveal the problematic frequencies, which you will need to know in order to design your floor. The resonant frequency of your floor must be no higher than half of the lowest problem frequency. So if your find a problem at 30 Hz, for example, then your floor should be tuned to 15 Hz or lower. - Stuart -