Control Room Wall design

[lukejs]

My control room wall to live room 1 is constructed with a slab of cement board sandwiched by two peices of styrofoam, then drywall, and a half inch of Georgia Pacific Steady R sheathing, and I am planning on just putting carpeting over the top of this, and then put in the wooden frame for the windows, and call it a day... Should I build a frame with 2 x 4´s in back of the wall , and build another wall behind it, or is it ok the way it is ? I´m worried about low frequencies passing though... I´m pretty sure mids and highs will be blocked.. Here´s a photo...... Thanks for any tips... Luke

[joeq]

when I built my wall, I set up the bass amp and the drums in the live room and had somebody play. ( It was a double wall construction with a gap). To my dismay there was not as much isolation as I was hoping for. I added another layer of sheet rock to each side and that did the trick!

You don't say how thick your cement board or sheet rock is. Why not just finish the wall the way you have it and test it out with bass and drums? You can always add mass or add the second wall if you don't like what you hear.

[Jeff16years]

i'm no expert but i would say the cement wall is good in the mass catagory but you need some space for the low freqs to dissolve. build another wall in front of it with a minimum 1" gap between the walls. do not let them touch.

put a 1/4" strip of rubber under that 2nd wall between the 2x4 and floor. sheet rock BOTH sides of that wall and insulate it with regular insulation -the pink stuff works well (minimum r-13)
that should do ya

[Jeff16years]

oh yeah, do 2 layers of glass in your windows with as much space as possible between the 2 layers (maybe 2" if possible)

[crna59]

Originally Posted by Jeff16years

oh yeah, do 2 layers of glass in your windows with as much space as possible between the 2 layers (maybe 2" if possible)

Make sure the glass is laminated! Very important!!

Regards,

[sounddevisor]

Hey, Luke -

There's something you should be aware of about isolation. It looks from the photo like your floor is continuous between your two rooms, right? And it hard to tell from the photo but I'd guess the same is true of the ceiling. The problem is that real low end vibration, which is the hardest to stop, will travel through the structure - in this case the floor, through that beam in the photo, probably through the ceiling also. So there's a limit as to how much isolation you can acheive. Adding more mass and an air space will probably help down to a certain point, but don't expect miracles. How loud do you plan to monitor, and how much isolation do you need? Maybe less than you think - if you monitor loud while tracking, you won't really care about some low-level bleed. right?

[Gnash]

Man, I had my control glass installed with a slight angle. I was gone the day my friend installed it. When I came back, he had angled the outside glass, which I expected, but he also angled the inside (control room side) glass as well. It has a V shape. I wonder if the CR side angled, was a bad or good idea?

[stevep]

Originally Posted by lukejs

My control room wall to live room 1 is constructed with a slab of cement board sandwiched by two peices of styrofoam, then drywall, and a half inch of Georgia Pacific Steady R sheathing, and I am planning on just putting carpeting over the top of this, and then put in the wooden frame for the windows, and call it a day... Should I build a frame with 2 x 4´s in back of the wall , and build another wall behind it, or is it ok the way it is ? I´m worried about low frequencies passing though... I´m pretty sure mids and highs will be blocked.. Here´s a photo...... Thanks for any tips... Luke

Dude....... That Black board Says COMBUSTIBLE

will this pass CODE ??????

Please Dont put carpet on your walls,

Styrofoam, carpet,and that combustible board i think would be a fire hazard

Here is a really good website to check out,


http://www.johnlsayers.com/phpBB2/index.php



Also You want 2 leafs not 3.



also Ethan's Site has some really good info


http://www.ethanwiner.com/acoustics.html





steve





.

[Jeff16years]

Originally Posted by crna59

Make sure the glass is laminated! Very important!!

Regards,

i learn something new everyday (not a surprise because i'm an idiot)

what's laminated glass?

thanks for the info.
-Jeff

[jayfrigo]

Originally Posted by lukejs

My control room wall to live room 1 is constructed with a slab of cement board sandwiched by two peices of styrofoam, then drywall, and a half inch of Georgia Pacific Steady R sheathing, and I am planning on just putting carpeting over the top of this, and then put in the wooden frame for the windows, and call it a day... Should I build a frame with 2 x 4´s in back of the wall , and build another wall behind it, or is it ok the way it is ? I´m worried about low frequencies passing though... I´m pretty sure mids and highs will be blocked.

Mass is good, but decoupling each room's surface with an airspace will buy you more than adding a couple more layers to the sandwich you already have. This means a staggered stud wall (looks too late for this) or a second independent wall. Insulation in the airspace is also very helpful and not very expensive. Also, if you don't build the window correctly, the best-built walls will do little good. The composite Transmission Loss of a mixed construction is very much limited by its weakest link. If you decouple the walls, be sure to avoid flanking paths. Also, don't expect absorption (like the carpet) to provide any additional isolation. Absorption in the receiving room can indeed provide some NR in the reverberant field, but it does not improve the TL of a construction.

[jayfrigo]

Originally Posted by Gnash

Man, I had my control glass installed with a slight angle. I was gone the day my friend installed it. When I came back, he had angled the outside glass, which I expected, but he also angled the inside (control room side) glass as well. It has a V shape. I wonder if the CR side angled, was a bad or good idea?

Not a problem; in fact most studio windows are built this way.

[lukejs]

Thanks for the advice ! I had an idea that the sandwich idea may not have been the best... I should have left some air in there. The cement board is about 1 inch thick. I think I´m gonna go ahead and put a 2 x 4 structure behind this wall, and put in some fiberglass insulation, and sheetrock, or wood panels for the inner wall. As far the control room window, I was thinking of making two window frames... since it would probalby be better then having two windows share the same frame...this would cause more transmission from coupling, right ? But I always see just one frame in most studios.... wouldn´t two be better ?

[joeq]

Originally Posted by lukejs

... As far the control room window, I was thinking of making two window frames... since it would probalby be better then having two windows share the same frame...this would cause more transmission from coupling, right ? But I always see just one frame in most studios.... wouldn´t two be better ?

sure- any decoupling you can add will help. How much, I don't know. I have two separate frames, one on each wall and wide enough to almost touch- with a rubber gasket in between. Its been there since the beginning so I have nothing to compare it to, but if nothing else you can point it out to people and they will think you are a crazy maniac who will stop at nothing to get a better sound.

[lukejs]

Originally Posted by joeq

sure- any decoupling you can add will help. How much, I don't know. I have two separate frames, one on each wall and wide enough to almost touch- with a rubber gasket in between. Its been there since the beginning so I have nothing to compare it to, but if nothing else you can point it out to people and they will think you are a crazy maniac who will stop at nothing to get a better sound.

Yes...that´s me ! a crazy maniac who will stop at nothing to get a better sound !! So...I´m gonna put in two frames.... Thanks for the advice !