John Sayers' Recording Studio Design Forum Archive

I finally got the power hooked up yesterday and got to run some isolation tests from my live room to the outside world and from the live room to the control room.

I had a boombox cranked to full volume (100db was as loud as it would go)

First the good news - live room to outside - basically perfect. Ambiant noise is about 40db where I live and I could hear nothing from the live room at all that raised the sound meter above 40db.

The bad news (well maybe) - Live room to Control room - At 98db in the live room I am showing 56db in the control room on a C weighted index. As things stand the control room has no absorbtion on any walls or the ceiling and the ceiling has two four inch holes into the ceiling cavity where I took some down lights out that I have not fixed/plastered up yet.

I suppose I am a bit disappointed in the isolation to the control room. I know this will impove slightly once the ceiling holes are fixed and some absorbtion is put up around the control room walls and some bass trapping done in the control room but I thought it would be a bit better with a double wall, double doors and double windows. I have been fanatical about sealing and caulking. It's not a disaster by any means as you can easily have a conversation at low volume in the control room with the stereo full bore only a few feet away but its not what I thought it would be.

I know it will change things once the monitors are in as the focus of the sound will change from the live room wall to the control room monitors but I would be interested to hear from others what kind of isolation they think is acceptable from one room to another for a project studio.

Ps: my wall construction live room to control room
2" 703 in 3" studcavity
13mm sheetrock
75mm fluffy insulation in 2" airgap
3"stud with insulation
2 layers 13mm sheetrock
notes: the liveroom wall is "inside-out" and rests on rubber top and bottom.


JohnG

I'm guessing the holes in the ceiling for the can lights are creating quite a problem for sound isolation. That's why I went with surface mount track lighting. The only holes in my ceiling are for wires sticking through, and I caulked around the wires. I wouldn't get too down on yourself just yet.

Also, from what I understand, absorbtion and bass trapping won't help isolation from one room to the next. Those are more for controlling the sound within a room; getting rid of reflections and modes. I wouldn't expect much isolation from room treatment.

Once I get the glass in my window and the doors up I'll let you know what my control room to live room isolation is.

Aloha JOhn,

Hey, sorry to hear (no pun intended). If it were me, it'd be no laughing matter.

I had a couple of thoughts on "why?" it happened, perhaps.

wall construction live room to control room
2" 703 in 3" studcavity
13mm sheetrock
75mm fluffy insulation in 2" airgap
3"stud with insulation
2 layers 13mm sheetrock
notes: the liveroom wall is "inside-out" and rests on rubber top and bottom.

Could it be because of the single layer 13mm sheetrock in your inside out wall? If so, would adding a 3rd layer to the control room side, perhaps using green glue help? Just a thought...I'll keep chewing on it.

Aloha

Thanks Guys,
I worked of a design John came up with for this wall. He seemed to think one layer inside and two out side had worked OK for him in the past - as long as I used a total of 32mm plasterboard - maybe I somehow misunderstood what he meant here - it's possible.
Yep, I can always add another layer to either the live room wall, between the studs or to the control room wall - I guess I will get the ceiling fixed up and see how it improves the situation and go from there. It's not too bad - just not what I thought it would be
Theres also a few other things here and there that need to be fixed up so I will get stuck into this and see how we go.
The good thing is that my neighbours should be happy!!
JohnG

John, you're probably doing as good as can be expected under the circumstances; throughout your project you've commented about saving money and not using any more material than absolutely necessary, so after a few of those comments I stopped thinking you cared as much about isolation as you did about cost and removability - these are pretty much an "either-or" situation, and you made it pretty clear what your first priority was ($$$) - If I read you wrong, I'm sorry - didn't intend to at all.

If you add another layer to your wall (preferably WITH green glue, but this stuff isn't cheap EITHER) it will help noticeably, no matter WHICH leaf of the wall you do (but moreso in the single layer one, it's just that it would all have to be done between studs at this time, right??!?)

For a "temporary" studio, it sounds like you've done about as good as you could expect - TOTAL silence between rooms is REALLY expensive, and NOT temporary... Steve

Hi Steve,

Thanks for dropping by and all your help with the project so far.
You are correct I was/am on a tight budget due to a young family and a big mortgage!! - I realize I made a few shortcuts - nature of the beast with a limited budget I suppose. I just wonder why John suggested a single layer here - maybe I just misunderstood him.

It's not a biggie to add another layer of 13mm board, It might actually be easier between the studs as its a small wall with the window and doors taken out and the plastering is finished and sanded on the other wall anyway. There is probally only about ten small cavities I would need to cut out, glue beef up sheets into and caulk - no biggie to do this . It sounds like not too much cost or work for a decent return.

Thanks for your help again.

I will keep you posted with the ongoing developments

Much appreciated

JohnG
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