Good Day AVS!
I'm a long time lurker. I have read over different threads multiple times over the last year and a half. I have learned a lot, and I think that I understand the basic concepts. My initial motivation was to soundproof the garage so that I could do my woodworking any time and not bother anyone in the house (that is still ongoing due to budget cuts).
I have a question, it is not about building a home theater, but about soundproofing a suite in my house. I apologize for this, and totally understand if my post gets removed, I do not know of a better place to ask though. This thread and Gearslutz has been the most informative I have found with anything soundproofing. But who knows, maybe one day, I will be able to afford a little theater in my house. Then all this experience will come in handy.
Downstairs we have a rental suite which consists of living room 2 bedrooms, and the worst form of sound control imaginable. This sound situation has been brewing for a while, and I feel that we are at a tipping point. We want to borrow a bit of money, reno the suite and rent it out for more (it is quite below market value right now anyway). The suite has very high ceilings, and I want to employ the decoupling concept here to reduce our footsteps, run a bit of ventilation between the ceiling and floor, and overall kill sound transfer. The plan was to drop the ceiling, then use DD 5/8" with GG. I was planning on double studded wall on one of the walls bordering the garage, but no such arrangement for any other walls. The one thing that I do not understand is the triple leaf effect, and how it will affect my situation. If I drop the ceiling in all 3 rooms, it will create a giant void space between all the rooms. Will this worsen my situation? Below is a quick drawing of what I mean with the void illustrated in yellow and layout of the suite with proposed double stud wall.
1. Would installing blocking between studs at the ledger joist (and insulating them with acoustic caulking) help the situation?
2. If I do as described (and I am only concerned with sound between floors), do I need to install DD and GG on the walls or would doing this on the ceiling and blocking mentioned be sufficient? I am worried about flanking, but would blocking take care of that? Adding second layer and GG on all walls takes the estimated cost up 3.5 thousand.
3. Should I leave drywall (or install new) in the void space to keep the rooms separated?
4. Can the void be too big? (I am planning 4 inches between new and old joists. Bottom joists will have to be 2x10, top joists are 2x12 i think.
Any advice, insight and wisdom is greatly appreciated guys! Again, I apologize this is not about an actual theater.
PS I should add, main source of noise is the living room, this is what I REALLY want to isolate, but with flanking I feel like I have to soundproof the whole suite.