Thank you so much for the reply!!
1. Are resilient channel strips/hat channel and clips "worth it"? If so, is it sensible to only have them on the ceiling and/or shared wall (the two most sensitive spots)? In that vein, is it worth it to drop the ceiling down with 2x4s to put another layer of insulation in (as described above)?
for isolation to work, you really need to do it in 3 dimensions. doing sound isolation on a single wall or portion of the ceiling is generally ineffective. as far as resilience strips - the better choice are isolation clips and hat channel as they're more structurally sound and reliable. but also more money.
Gotcha. I'm mainly concerned with the footfall sounds from the room above, so that's why I was thinking maybe only doing the ceiling would be sufficient. So basically if I did it, I would do it on every interior wall of the studio (including ceiling)? The cost is a concern of course, but do you have any sense of how much of a difference we're talking about? Like, 10% better, or 50%? Obviously this is imprecise, but I'm just trying to gauge if it would make a truly significant difference.
2. Would it be better to caulk all of the cracks in the ceiling, or just do two layers of drywall? Not sure which is easier. Or both, if it's worth it.
caulk everything. you will learn to hate caulk. but caulk is your friend. caulk everything. when it doubt add more caulk. remember backing rod is caulks friend. use backer rod to ensure proper contact for the caulk.
Point taken, and this is of course what I was hoping you wouldn't say
3. Has anyone tried a single room ERV like the Panasonic WhisperComfort ERV? Does this make sense? It's the only way I can think to ventilate the room.
the Panasonic ERV are nice units. just make sure you're isolating them from the room for air silencing and including vibration mounts.
Sweet, thanks! I'll have more questions about this when I start figuring out the silencer boxes for this and for HVAC, but I think this is my best (only?) option for ventilation.
4. Should I put drywall on the inside of the boxes/soffits around the ductwork? Like, enclose them completely, so the ductwork is not in the open spot between leaves?
once the duct has been safely penetrated into the room (or out of the room) using the attenuators, you can route the duct however you like. the attenuators work because they mimic the mass of the walls or ceiling, and they have a convoluted path so there is no direct passage of sound through the wall/ceiling penetrations. it's always a good idea for the room-side ducts/plenums etc to be expanding to reduce the flow velocity (which reduces vent noise and general "wind" in the room which your mics can hear even if you cannot.
Apologies, I was being unclear here. There are already two duct runs that are in the room, and that can't be moved. See pics below. So this is different from the silencer boxes, which I still need to work out before I ask for help. I guess my thought is, if I basically build around these the same thing I'm making for the walls, would that effectively "remove" them from the room. Like, frame around them and put two layers of drywall on both side of the framing, with GG and Safe n Sound. If that is still unclear I can try creating a Sketchup of what I'm talking about, or even draw it out by hand. It seems like it should work to my amateur brain, but then I also worry about whether I would be creating a three leaf situation above and behind the ductwork, or other issues that I don't understand. I could put another layer of drywall above (between the duct and the floor joists) and behind (between the duct and the existing back wall) so it was four leaves if that would solve the problem.
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5. Is a single solid core door (installed according to the commonly used approach found elsewhere on the boards) sufficient for the walls I have? I can't really do two doors, but I could do something crazy like build a door with insulation in the middle to basically mimic the walls.
a solid massive door which is damped and properly sealed all around will work.
Apologies for being dense, but what do you mean by damped? The method I was planning to use is basically what is described on this link:
http://www.johnlsayers.com/phpBB2/viewt ... 2&start=30
6. Is there a material (plywood, MDF, etc.) that is roughly equivalent to 2 layers of drywall with Green Glue? Specifically for the bottom of the box around the duct going into the hall to the laundry area. Head clearance is a real concern.
3x 5/8" type X drywall is pretty much equal to 2x 5/8" type X drywall with GG in between. it's generally less costing in materials but adds more weight onto the structure and reduces your room height and wall widths by an extra 5/8". cement board of 3/8" is more slightly more dense than the drywall and might be an answer there.
I was being a bit unclear here as well. This is the other duct run that is currently in the room. See pic below. The height from the concrete floor to the bottom of this duct is 77", so adding in the floor I plan to put in, plus boxing around the duct could add up to 7 or so inches, making it so anyone over about 5'9" (like me) would have to duck their head. So instead of framing, if I could get by with a denser material just in this doorway area, I would very much like to. Or thinner framing with thinner insulation like OC 703 instead of Safe n Sound (2" instead of 3"). Even a couple of inches would make a big difference. I hope that makes sense. I'm having a very hard time explaining some of these weird areas of the room, and I know they will end up being the hardest to deal with.
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7. Do joists need to be beefed up or have insulation and at least one layer of drywall? My walls terminate on floor joists, so I'm worried about the other side of the joist (outside the studio). That is currently a ceiling with insulation and a single layer of drywall, but it's mostly open space and goes up to the kitchen.
if you're not building a room within a room, then increasing the mass and damping it are really the only options for more isolation unless you're using isolation clips and hat channel for the interior room mass. and even then, it cannot hurt to increase the wall in-between studs/joists and on the outside drywalls and filling with insulation.
Sweet, I think this makes sense to me.
The other thing I'm currently having a very hard time visualizing is how to deal with the ceiling area around the shared wall to the other living space. This is where my father in law basically lives now, which was not the original plan - the pandemic happened and he ended up moving in semi permanently. I could probably bulk it up and basically figure out a way to box it out and include it with whatever assembly I make for the duct over the doorway, but it's a tough nut to crack and any ideas or thoughts would be most welcome. The wall terminates between joists so it's basically open into the ceiling cavity of his room, not to mention the duct going through (the same one over the door discussed above). Pics below.
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Thanks so much for the help, I really appreciate it!
