I want to put an 11'x11' soundproof "booth" or room in my 19'x23' cinderblock detached garage. It will be used for movies, music, video/music production, and perhaps studio recording. Sound isolation is the highest priority as the neighbors carriage house is a mere 10-15 ft. from my garage. I have been reading this forum non-stop for a couple weeks and here are my plans:
Double stud walls with 5/8 double drywall + GG and cheap insulation exactly like this:
The OUTER wall will have ceiling joists like this:
I haven't decided whether to use 2x4s or 2x6s as the joists (preserving height is an issue). I'm thinking double top plate. Maybe 90 degree L shaped joist brackets to help sturdy the joists to the top plate. DD + GG on top of the joists to make the "roof" of the "booth".
The INNER wall will be an inch below the joists, and braced to them with IB3 clips every 48 inches. BOTH walls will have their own seperate 4 inch rubber strips of 1/2 inch horse stall mats (from tractor supply store) between the bottom plates and the concrete foundation of the garage. Then the bottom plates will be sparingly nailed to the concrete foundation. Obviously 5/8 DD + GG for the inner walls.
I will use clips + furring channel on the ceiling only. I will start with double layer of 5/8 drywall + GG and may add a third layer. Cheap insulation in between the joists.
Still need to research this area more but double doors. I figure an exterior door on each wall stud and will frame each wall like this (ignore dimensions):
I may add mass to each door if recommended. Maybe extra nails into the concrete floor on the bottom plates and dual IB3 clips on the inner wall near the hinges. I don't know how high my floor will be yet so I'm considering raising the door opening so you don't have to step up into the room. Also will install jambs/doors first before drywalling. Any tips/recommendations I'm all ears, especially when it comes to sealing up and soundproofing the door jamb etc.
First I'm gonna lay down 1/2 inch horse mat rubber across the whole floor (but not touching walls). Then put some 2x4 framing WITH U-boat floaters like this OVER the 1/2 rubber mat (also not touching the walls, maybe a 1/2 inch from the wall):
Then maybe 2 layers of notched OSB with GG in between? Plywood? Low frequency isolation is a huge concern and I don't want bass from my subwoofer or a bass amp traveling through the ground and to my neighbors carriage house. I was gonna fill the floor with sand but then I spent 2 nights down that rabbit hole haha.
1 intake and 1 outtake vent on opposite ends of the room so it pulls fresh air diagonally like this:
There will be baffle boxes at each vent on the OUTSIDE of the room. I plan on constructing these baffle boxes very well, with inline fans, and maybe even covering the outside of the boxes with GG + drywall. I've seen people place their vents on the same wall, I'm not sure why you would do that though. Also worried about AC in the summer, I'm curious about a portable AC hooked up to the outtake vent (with an inline fan assisting the ventilation of hot air so it doesn't over burden the AC). But then it would still be pulling hot air from outside the booth. We'll see.
Rather than messing with a bunch of wiring, electricians, and acoustic putty, I'm thinking of running 4-5 heavy duty outdoor extension chords into the booth through one of the baffle boxes. Fortunately the garage is very well powered with it's own breaker box and I plan on running different extension chords on different breakers.
I'm just gonna hang some lights and use lamps off my extension chords.
I just know a square is better than a rectangle and I can work with that down the road.
The garage already has some ceiling joists that are 98.5" (8.2ft) above the concrete foundation. My dad kept insisting that I use those for the ceiling but I wanted complete decoupling from the garage. I considered IB3 clips but feel I this is better, unless any of your experiences differ. The DD + GG roof will be 1 inch below these GARAGE ceiling joists.
I'm pretty sure the garage foundation has footings. We are planning on digging down to make sure this foundation can support the weight of this before we start.
My buddy who is a contractor is going to go over these plans with me, but he just had a baby so I won't bug him (yet).
Lastly, thanks so much in advance for any help. My girlfriend is definitely mad at how much time I've spent reading this forum lately. I am addicted. If this is thread is in the wrong place, or the attached pictures violate forum rules, please lmk and I'll fix it.