John Sayers' Recording Studio Design Forum

So why are you asking this same question again if it has already been answered?

_________________
Brien Holcombe
_____________________________________________
Sound: You can't stop it, you can only try to contain it.

I'm actually trying to ask a different question, not the same one. But you are misunderstanding my question. I'm not asking nor did I ask about construction involving anything but a standard single stud wall frame. The question is: clips and HC on both sides (leafs) or only one? This is only a question for the wall btw the mix and live room.

Same answer...in the effort to decouple, you might use clips and track or RC on one side of the frame to decouple. You do not install either of these products on both sides of the frame.

It is always better to install a double framed (READ: fully decoupled) assembly between the control and live rooms for what should be obvious reasons.

_________________
Brien Holcombe
_____________________________________________
Sound: You can't stop it, you can only try to contain it.

OK, thanks, I'm slowly getting it! It is not intuitive!

Now, am I correct to install two layers of drywall on each leaf of this double framed wall assembly, but have their thickness differ: 5/8x2 on one side, and say 1/2x2 on the other?

It has nothing to do with intuition, it is always about education and information.

I cannot say you are incorrect but I will say this. The reason that differing thicknesses might be used is for the effect called refraction. This is almost always a technique used by, if at all, a qualified acoustical technician with a lot of math running around in their head for a specific problem or concern.

In the world of small rooms and basic isolation, you would use the same type of material on whatever frames you install it to since the mass is what you want.

Mass law predicts a 6 dB gain in isolation from simply doubling of mass. So if you take the 5/8 sheetrock and double it, you win since the 5/8 will out perform the 1/2 inch rock

If you double the 1/2 inch rock, you don't even have enough to equal the 5/8 doubled rock, so in that respect you lose.

The refracted sound gains you nothing.

The only one thing you are incorrect about, is this. In order for the refraction to actually work in an area that you can determine, you would actually place a thicker piece of mass against a thinner piece of mass, directly not on different sides of the assembly.

_________________
Brien Holcombe
_____________________________________________
Sound: You can't stop it, you can only try to contain it.

Thanks Brien. Intuition was not a good word choice; my experience so far is that sound isolation and treatment are far more involved and complex than I imagined when I first started on this project. Indeed, education and information are key.

I think, however, that I'll go with a staggered stud frame for the wall in question, to save money, with two layers of 5/8 on each side. So another question is, do I use green glue on both sides? There is a FAQ on their website which confused me, so I want to make sure.