Isolation with a drop ceiling: fantasy or reality

[floid]

The drop ceilings I'm familiar with are the type seen in commercial buildings and offices.
I'm not sure how much weight they can support.
They are suspended from the existing structure.
I would imagine the more weight they support, the greater the number of suspension points.
So working from the principles of 2 mass-ive leaves and decoupling... Personally, speaking as a total non expert, I'm not sure it will accomplish what you're hoping. As I understand it, they're primarily useful for taming ceiling reflections in the vocal range - sort of like a lightweight version of a cloud over a drum or mix position. Attenuation is doubled below, since reflected sound makes two trips through the absorptive panel, compared to attenuation above.

That's a really busy floor/ceiling assembly, so this might be a worthless suggestion. But would it be possible to run a second set of joists between the existing ones, on a slightly lower plane? Since they would only be carrying a ceiling load, they could probably be smaller dimensional lumber than the floor joists. So if you have 2x12 floor joists, and ran 2x6 or 2x8 ceiling joists between them 2" below plane, for example.
Access to plumbing and wiring would be the obvious problem with the scheme.
Access to plumbing and wiring is a problem in slabs and second stories as well.

[MoreSpaceEcho]

that's a solid idea, but from looking at the pic, he'd have a hell of a time actually doing that.

the soffit idea could MAYBE help? i'm not an expert either. but...maybe. i'd make the soffits big enough to put a layer of insulation around the hvac ducts, i'd think that would at least help block some of the higher freqs from travelling up to the kids' room.

[goldstar]

If you think your source of transmission is the ducting, your soffit idea may be enough to get some isolation. You may want to consider insulating the ducts themselves rather than adding a full-on soffit. This would help keep them from resonating and carrying sound up stairs. An HVAC contractor might be able to help, but most won't understand what you are trying to achieve, and most of the insulating material they would use is not massive enough to really help much with sound; they generally insulate to avoid heat loss thru the ducts instead of for sound iso.

If you are totally stuck for a solution, send me a pm and I'll send you my phone number and could maybe stop by for a look. I've done a lot of studio construction and am in Boulder occasionally. Consult fee is probably a couple of beers at the Southern Sun.

Frank
Denver, CO