Control Room Design - Room Inside A Room

Hi there I am a first year Music Technology university student and for one of my assignments I need to design and equip an industry standard recording studio. For the design, I plan to have my control room enclosed in another room, the "room inside a room" approach. I was wondering if anyone would be able to tell me how far appart the inner room walls should be from the out room walls, or is you could point me in the right direction to find out this information? Thanks a lot!

outer wall dimensions? LxWxH?

How much isolation do you want? Read the before you post at the top of the forum. You are doing everything but actually building the studio. All the questions are germane. You are doing this as a student. At the top of this forum is a Reference Area in that there is a link titled More Useful links. Granted it is buried in the Door Seals heading. There is a link to NRC IR 761. The title of the link should make it obvious. As you study the document and Tl curves, you may want to consider a concrete block/drywall 2 leaf system for better LF isolation. NRC IR 586 will show you TL curves for various concrete block walls. Andre

I think I've hear somewhere that 200mm is good, obviously the bigger the better.

It all depends on what your basic design parameters are! Without knowing that, it's really hard to even guess at an answer. How much isolation does your hypothetical studio need? And what are the current hypothetical noise levels that it has to deal with? For example, if it is hypothetically sited next to a railway line or under the departure path from an international airport, that is rather different from a hypothetical location in the middle of the countryside, miles from anywhere. So, once you have your basic hypothetical situation in place, you can hypothesize about what type of hypothetical recordings will be made there (10 piece heavy metal rock bands? Full symphony orchestras? Or a lone harmonica player?), and then figure out how much isolation you will need for that scenario (in terms of transmission loss curves). Based on that you can figure out the best construction materials for that design, and that, in turn, will tell you how much air gap you need. Sorry to be so obtuse and indirect, but basically you are asking "How long does a piece of string need to be?". The answer is: it depends on what you want to do with it. However, that said, you'll find a lot of recommendations here for something like a three or four inch gap between the inner and outer stud frames (assuming that your hypothetical studio will be built with stud walls). If those are 2x4 frames with a couple of layers of drywall in each side, then you are looking at roughly 12 inches total wall thickness. More is better. Other people live with a one inch gap just fine. It all depends. If you are really serious about doing your design project right, then I'd suggest that you buy Rod Gervais's book: viewtopic.php?f=2&t=5670 Hands down, it is the absolute best book on the subject. Good luck with your project!

AVare wrote:

you may want to consider a concrete block/drywall 2 leaf system for better LF isolation. NRC IR 586 will show you TL curves for various concrete block walls.

Andre, thank you very much for pointing to that document, it helped me to get a few things straight for the concrete block/drywall wall I'm planning to use for my studio. I found particularly interesting the formula for calculating the wall's resonant frequency. In my case, when a wall separates you from a car's engine, roaring and screaming 2m away from you, you better have a wall cavity that resonates at the lowest possible frequency. The thing that puzzles me though is, where does the number 43 comes from? Or the 60, in case the cavity's left without insulation? I mean, I know it represents a frequency measurement but for what? And why does it take into account only the drywall's mass and not the concrete wall's mass as well? Is it the same situation if you have a 15cm concrete wall leaf and a 30cm concrete wall leaf? I wouldn't think so... Sorry for hijacking this thread like that, but I had to ask... :oops: Edit: Well, I thought about it and I think I got it. The 60 and 43 numbers should represents some kind of variable that depends on the material you place between the leaves. 60 for air, 43 for insulation. They don't take into consideration the concrete wall's mass because they assume that the concrete wall is the SOLID, FIXED mass and the drywall is the one that resonates. Hmmm.... and what if you wanted to calculate the resonant frequency of a drywall-air-drywall wall, I wonder...?

Thanks for the replies people, has been a lot of help!