John Sayers' Recording Studio Design Forum

Hi All,
Long time lurker and rare poster here. I’ve been reading Rod’s excellent book and following posts here. Thanks to all you pros for your invaluable help and advice.
I bought a home last year with an attached garage that I want to turn into a piano room for recording and teaching ( of piano and other acoustic instruments primarily. ) My wife plays professionally and teaches. I’ve been a recording engineer for 35 years. And still love it.
I'm in a semi-rural area on a fairly busy road with a small local airport not far away. Noise levels outside are typically 65-80db. Worst offenders are large trucks, helicopters and old bi-planes. My main concern is keeping exterior noise out. Not keeping prog/metal drums in. The garage is appr. 24’x24’. My lame newby sketch-up shows what I am proposing. I'm planning on setting some large microlam beams to support the roof and pulling all the ceiling joists out to gain some height. I’ve had this engineered already.
My first questions is about the dimensions. Is 20’x18’x with a sloped roof-(8’8 to 12’ too close to square? I have to carve out a bathroom, utility room and entrance/ waiting room somewhere in the space. This is my best layout guess to date.
Next the ext leaf. I have two walls that are brick up to the eaves. And standard sheathing/ siding on the gable end above. I'm assuming I have to beef up the gable end to make a similar mass to the brick below it? Fill in w/ drywall and caulk? Also can I gain anything by adding more drywall mass behind the brick and celotex?
Next. How do I build up 2 interior stud walls to match the mass of the brick ext walls. I’m hoping to stay with single stud walls. 2 layers of 5/8” with either RC channel/ RISC clips or Green Glue to help out. Am I dreaming here?
I am open to any and all advise,
thanks again to all ya’ll
James Tuttle
Hygiene, Colorado

If you want a really simple solution, here is what I would do. Angle that whole wall where you are proposing to put in the utility room, bathroom, waiting room.. By like 12 or more degrees. Now you you avoid flutter echo Between your new wall and the parallel wall and avoid the close to square dimension problem. Build another frame in front of the wall that is to the left of the piano, opposite the door and fill with insulation, cover with fabric. Paint or stain that concrete floor to look awesome. I might not worry about anything else! You will have no flutter, a good amount of bass control with that huge insulation wall, and still a bunch of bare surface to keep the room bright. Adding some diffusors in the room would probably make it sound even better.

I think your sound proofing plan sounds fine.. Building a single stud wall is all that you SHOULD do because the exterior brick walls are your second leaf, and as repeated a zillion times on here, data shows that a two leaf system, and only a two leaf system, is the best way to get the most amount of sound transmission reduction. You could even leave 6" or more between the brick wall and your new walls if you want them to be even more effective because the amount of space in between the leaves is a huge factor in sound transmission loss as well. As long as you seal, build the ceiling right, insulate, do those walls like I mentioned, with adding 2 layers of that drywall, green glue, jeez.. I think you should be fine.. Try to keep that inner wall and felling decoupled from the outer leafs.

if you're adding a framed interior wall off the brick, then skip the RC etc as it's already decoupled. if you have the option to open the ceiling and cathedral it, that would be nice but may complicate the isolation a bit as you'll still need to ensure venting of the roof plus the beef up mass and then use isolation clips and hat channel as the inner isolation layer. angling the long inner wall is a good idea. remember to account for the HVAC and related isolation as waiting to do this as part of the design can be a problem. perhaps only cathedral the ceiling over the live room and have the isolated duct vents in the angled wall above the brick wall line.

_________________
Glenn

Thanks for the replys
Can I achieve some variation in the ceiling by utilizing the 18" height of the beam to vary the hanging height of the new ceiling joists?
Also, how much of an offset in the sidewall do I need to achieve a significant improvement in flutter? Is 1'6" in a 19' run enough? Please see the attached sketchup pics.
thanks again for your time and expertise,
James Tuttle