RICK FITZPATRICK said:
Now SCREW or hold up a second or more layer with perimeter wood cleats, screwed to the joists.
You're talking about something like screwing a 2x2 cleat to the joist, then screw one or more layers of sheetrock to the cleat?
Would angling the sheetrock help dissipate the sound inside the room? I.e. so that at one point on the joist it's, say, 2" from the bottom, while at another point it's, say, 4" from the bottom, then back to 2, and then 4, and so on.
RICK FITZPATRICK said:
Again, Resiliant channel, and Risc clip on hat channel are two options. The latter being the better of the two, although more expensive and time consuming, although it will also carry more weight...HVAC ducting to other rooms and ANY duct connections to the basement with these same ducts must be addressed.
Yar, here's where we get into the tricky bit. Several 7" HVAC pipes go across the joists immediately under them. I might convert them to 4" pipe or try to find a rectangular pipe which is 4" deep. Hanging the ceiling at 7" below the joists is too low for guys like me...4" is more like it although even that may be too much for the whole room.
Hence, my desire to wrap the piping in some kind of mass so that the HVAC is on the outside of the room and not acting as a conduit for sound (100dB coming out of the vents and cold air returns would make this whole thing an exercise in futility!)
RICK FITZPATRICK said:
Tell us some more about your plans and what exists and we will try to illuminate some dark corners.
fitZ
Once I get the hung ceilings out of the basement I'll take some pics, and once I have 'net access at home I'll post them someplace, and we'll save thousands of words!
C