Seeking advice for a temporary tracking room

First off, great forum and has provided me with much help in treating my mixing room at home. I'll try to be brief: I bought a house on the west coast of Vancouver Island, far from my home turf in Toronto. I am in the process of re-establishing myself here and have worked out of my home so far. In looking for a decent room to track, possibly mix in as well, I came across this room for inexpensive rent. In about 3 or 4 years, I want to build an addition on to the back of my home so this will be my studio until that happens. I don't want to sink TOO much into this for that reason. I have done nothing to it yet other than snap these pics and my budget is $3000.00 to get it into recording shape. Business has been better that expected here, although I am not solidly booked yet, I am getting bills paid. I don't have a large investment. I plan to make upgrades on this space as time goes on: to an extent. It is a rental after all and things can change. What I am hoping for is some feedback on my ideas, additional advice, and some answers to a few specific questions...and A BIG THANKS TO ANYONE WHO RESPONDS IN ADVANCE!!! Here is the raw layout: PIC 1 Here is the Layout with some of my initial ideas: PIC2 Ideas: - extending the control room to 15'6" x 8'. Soundproofing that room - building some gobos and corner traps, wall diffusion, ceiling cloud. - I need to contain that heating duct. Either frame it in or build a whole wall down that side. - an iso booth here are some room pics (the mess is from the owners and will be cleaned up): This shows the long wall with the heating duct. This is sure to rattle and resonate with unwanted noise. Another option is just build a wall along that side and cover it. This might also make for a better room ratio - or it might not. This shot shows the room from the front entrance doors, down the length diagonally. The floor is concrete, the walls are concrete on the botton half, and plaster the rest of the way up. The ceiling is hard plaster of some sort or drywall. This shot shows the room looking from the middle towards the entrance. The white wall on the left is the prospective control room. That needs to come out about 6 feet. I will be tracking bands of different genres: drums and not, singer songwriters, overdubs, voiceover work. It is on the basement level. BTW...There is the most awesome reverb chamber upstairs not in use...a large community center with arched ceilings and tiled walls. That is a fantasy come true! Noise leaking out or in is not a problem here. Here are my questions: 1. Should I build double walls for the control room or is there another way of constructing walls that is effective, less bulky, and inexpensive? I likely won't do critical mixing in there but I want to hear how my mics are sounding while checking instruments without room interference. 2. What amount of absorption, diffusion is necessary for a room this size? I have built corner traps and bass traps effectively for my small mixing room at home. Now I need to treat this larger space. I like the idea of panel traps because I can take them out should I leave this space. 3. That heating duct is going to rattle. I am thinking about building a wall along that side and insulate it (if I can afford to). If I build a wall, this is going to change the shape of the room. How can I do that in an acoustically positive way? Angle that wall? Make it to a specific dimension to get a good ratio? What would that ratio be? 4. The ceiling needs treatment. Right now I am thinking of some panel traps mounted from the ceiling. Does anyone have an ingenious way of making an inexpensive cloud suited for a temporary room like this? 5. How will the concrete floor affect the sound? Any help is appreciated greatly. John

Hi John, and welcome! There is an announcement at the top of the forum about what to do to assure getting as many responses as possible. The announcement leads to this post. Actually, several people, who are experts on this forum, will not reply if you do not do what is written in the post. Many others who are very helpful, will not reply out of respect for the moderators' wishes. However, two quick comments:

1. Should I build double walls for the control room or is there another way of constructing walls that is effective, less bulky, and inexpensive?

Nope! Sorry. Two-leaf MAM wall is the cheapest most effective way to get good isolation. The only other way is with a ten-inch reinforced concrete wall. You can't cheat the laws of physics. To stop sound, you need mass (or a vacuum). The cheapest way of getting mass is with sheetrock. The bulk is part of the MAM system: You have to have a decent air gap between the leaves, or you don't get decent isolation.

How will the concrete floor affect the sound?

Great! The general consensus here is to have a live floor and an absorbent ceiling. Concrete is good for a live floor. Or you could glue laminate floor to it. to ,make it look better. If you want it deader, scatter some thick throw rugs.

What amount of absorption, diffusion is necessary for a room this size?

Absorption? Lots! Large bass traps in all corners, to start with. Diffusion? In the control room, none. It's too small for diffusion to be effective. In the live room? To taste. - Stuart -

Thanks for the welcome and the advice Soundman. I made some changes based on the guidelines. I will research the MAM walls you refer to and get back here if I have some questions about their construction. Thanks again John

John Gilbert wrote:

Thanks for the welcome and the advice Soundman. I made some changes based on the guidelines. I will research the MAM walls you refer to and get back here if I have some questions about their construction. Thanks again John

We'll keep the light on ;)

Bear with me fellas, I have done some research on the control room walls. There is a lot of technical information to sift through and I don't understand much jargon. Not much of a builder I'm afraid. I do have a carpenter who will do the work, but I need a design for him to follow. From what I've gathered so far, it seems I need to build a double wall, insulated and with 2 layers of sheetrock on the outsides of each wall. I'm getting there. Once I find the design. check the cost of materials, I have to figure out how wide these walls are going to be exactly. This is a small control room to begin with. The width of these wall may force me to take another approach. I'll be back here when I get a definitive wall construction plan and then I can bounce it off you fine people. I also have the issue of the heating duct. I figure I will put a wall up there but I don't know if I should angle it or not (for acoustic purpose, and how much of an angle)

Don't worry, John! I understand you perfectly. Several months back, I was where you are now, bemuddled and confused. It takes a while to get your head around some of this stuff, since it isn't intuitive. Sound does not act the way we tend to think it does. Once you get the basics in place in your mind, it starts to make more sense. Hang in there!

From what I've gathered so far, it seems I need to build a double wall, insulated and with 2 layers of sheetrock on the outsides of each wall.

Exactly. That is "MAM". Mass - Air - Mass. Or more correctly "MSM", Mass - Spring - Mass. The sheetrock on each side is the mass. The air trapped in the middle plus the insulation acts as a damped spring.

I'm getting there.

Yup!

Once I find the design. check the cost of materials, I have to figure out how wide these walls are going to be exactly. This is a small control room to begin with. The width of these wall may force me to take another approach.

To get the best isolation, your entire wall will be around 12 inches thick. That includes a 4-inch air gap, two 2x4 frames, and the thickness of the double sheetrock on each side. You can do it for less, but you sacrifice isolation. You can do it in about 8 inches by using staggered studs on a 2x6 base, plus double sheetrock on each side. That will cost you up to about 10 dB of isolation, depending on how you build it. You can even do it in about 6 inches, using a single 2x4 stud wall, with resilient channel on one side, plus double sheetrock on each side. That will cost you another bunch of dB in isolation. If you absolutely must have a thinner wall with better isolation, then that too is possible, but the cost goes way up. Now you have to start thinking of extremely dense materials instead of sheetrock. Things like concrete, steel plate and lead plate. It can be done, but you better have a big budget: sheet lead is just a tad more expensive than sheet rock!!!! Unfortunately, you cannot beat the laws of physics. There are only a couple of ways to stop sound. And they require lots of space, lots of mass, or lots of money. There is no such things as a cheap, thin, lightweight wall that is effective at stopping sound from getting through! - Stuart -

Thanks again soundman, I found this: http://christianproaudio.com/studio_construction.htm which gave me a good primer on walls. I now have a good idea about the basics and enough information to get a materials list together. I am still in the dark about where wall meets wall, meets roof, meets concrete floor. I am reading a bit about walls being sealed and that walls should not be solidly connected (is this correct?) I have also figured out that this fellow named Rod G. has a good book and that I should buy it. I will, and hope it has the answers to these questions. I am still curious about the wall I want to angle. Is it a good idea? and how far into the room should I bring that wall for ideal acoustics? ... and also the cloud above the recording area. If the height is only 8 1/2 feet, should I be going for broadband absorption or diffusion for this? How big should corner absorbers be for a room of this size? Thanks