John Sayers' Recording Studio Design Forum

Following up on previous threads, here's a first stab at an actual design. My background noise runs around 51 db from the street, peaking at 76 db when someone beeps a horn or something.

I was looking at QuietRock drywall (http://www.quietrock.com/). Wondering if I'll need more than one layer against the attic rafters with resilient channels.

In any case, any thoughts on the basic design for the studio and control room given the available space?

I'm hoping the floor won't need any sound-isolation treatment. It's my own apartment below the studio.

--Nick

Hey there!

I am NOT a professional nor even an experienced individual in studio design. I try to gain knowledge from the site and enjoy reading all of the posts while I plan my own basement studio.

I have one thought on your post that is what I feel will be a viable question to the helpful pros here regarding the dimensions of your control room:

Is that wall dividing the control room and live room existing or is it presently one big open area? This will matter because you want your mixing room to be among certain optimal ratios. If you have the ability to put that wall wherever you want it, you can plan for your control room with much more open-ended options.

I would swap the CR and live round so there isnt any through traffic going through the live to get to the CR. You could also use either sliding doors or windows to ensure good comunication between walls. Maybe a little store room or machine room if required. Attached is just a example to give you some ideas, not to scale or anything, just ment to get you thinking

Adding to what others have said, I don't see any isolation plan! There will not be much isolation between those rooms, since they are firmly coupled on all sides. The double wall between them is a pointless waste of time and money, unless you also do double walls for all of the other sides of the both rooms, including the ceilings and possibly the floors. You cannot isolate two rooms from each other by just by building a single isolated wall between them, especially considering that this seems to be a second floor build.

You don't say how much isolation you need, but I'm guessing that you want a high level of isolation since you show drums in there, and mention street noise levels of over 70 dB. So I'd say that your first issue should be to define how much isolation you need, in terms of dB TL, then plan the construction to give you that level.

Mass is mass and sound waves don't care how much you pay for it. There are no magical materials that bypass the laws of physics. Sound waves are stopped by mass, decoupling, distance, damping and rigidity. They are not stopped by price tags or marketing hype.

So build the highest mass, thickest, most rigid, best damped, best decoupled structure you can afford, using the cheapest materials that fit the bill. It seems from that web page that the product you are thinking of using is two layers of drywall with some type of inter-layer between (CLD, maybe?), so if you can get that product at a lower cost per pound (or per kilogram) than ordinary fire-rated drywall plus GreenGlue, then it's a good idea. If not, then it's a bad idea. It will work exactly the same as an equivalent mass of ordinary drywall plus an equivalent CLD layer (if that is what it is), so the issue boils down to cost and installation. If it is cheaper per square foot of finished wall, then it's a good idea. If it is more expensive but significantly easier / faster to install then it is a good idea. If not, then plain old drywall plus GG will get you to the same point.

That web site does provide a "comparison" of such prices, but the major difference in all cases is from a curios factor called "Lost sellable floor space, at $200/SF". Take that questionable, irrelevant and undefined "factor" out of the equation, and the results are rather different! That factor is not even a "cost" at all! It's a fudge-factor, since the numbers are unattractive without it. Compare, for example, their own figures for a wall made with their product that is claimed to provide STC-51: it costs $5.86 per square foot of wall, according to them. They also claim that an ordinary staggered stud wall built with conventional materials will achieve STC-52, and cost only $5.46 per square foot to build. So that kind of answers your question, doesn't it?!!! A conventional wall is both cheaper and more effective at isolating, according to their own data.

The ONLY reason you might want to go with their more expensive and less effective solution, is if the extra space taken up by a thicker conventional wall would be detrimental to the acoustics of the room, or if you needed better isolation in the low frequency part of the spectrum (which you probably do).

That said, they also admit on their web site that their product alone is not very good at isolating low frequencies, since it is subject to the same laws of physics as all other products. Quote: "Bass frequencies are the most difficult sounds to effectively reduce and control when dealing with sound transmission. While QuietRock ES does provide noticeable sound reduction at all frequency ranges, the decibel level reductions in the very low frequency ranges (from 250 hz to as low as 50hz) are not as great as the reductions seen at the mid and higher frequencies." The lab reports they publish also show this. The solution they offer is as follows: "...a double layered approach with QuietRock ES using QuietGlue Pro between the two layers of ES would provide additional incremental reduction of the bass frequencies." In other words, you'd have to do the same with their products as you would with anyone else's products: double layers of drywall with additional CLD between. So the issue comes down to total cost again.

Don't get me wrong! I'm not saying their product is no good: I'm sure it really does work as advertised, since it has been tested in independent labs, and they have published those reports, which speaks well of them as a company: way too many manufacturers don't bother getting their products tests, and even fewer actually publish the results, so the fact that they do that shows that the are confident in their products, and that they do perform well.

So the question is not "will their products work as advertised": The answer is clearly "yes". The question is: "Can I build a better isolation wall more cheaply using their products". The only way you can answer that is by comparing the results and the prices that YOU can get in YOUR area for various types of products that will achieve the level of isolation that YOU need in YOUR room.

Will QuietRock work to isolate your room? Yup. Will it work better than the laws of physics allow? Nope. Will it give you a better isolated room at a lower cost? Maybe. Maybe not. Only you can answer that question, by looking at different construction materials and techniques that will give the level of isolation you need, then comparing the costs and the ease of construction.

That depends on how much isolation you need. What number do you have in mind?


- Stuart -

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I want this studio to amaze people. "That'll do" doesn't amaze people.

Thank you everyone for your input. I appreciate it.

I'm not sure how to decide on ideal proportions for the control room, but I thought the size I picked was about right in terms of volume. I can certainly set the wall at an angle.

Using dry wall with green glue is fine. I can do that.

How much isolation? The background street noise is just over 50 db. If a spike over 70 now and again gets through, I can live with that. But I need to mitigate that constant street noise. So I think STC of 50 to 55 would suit my needs.

I was planning to mount on resilient channels directly against the roof studs. I would insulate, of course, with batt fiberglass. I could go with two layers of 5/8" drywall with green glue between. Do you think that would get me up to the 50 to 55 STC?

--Nick