Ceiling Insulation Question + Ducts

[BlueAx]

Hey there,

I'm building a control room in my parents basement. Nothing insanely fancy, simple 2x4 stud walls with 5/8" drywall (one of the walls built will be doubled up with addition 1/2" drywall). Putting in a 32x80 door and a 4'x3' window. The room is about 11' x 13'. But I plan on treating it to get the best sound possible (without having a huge budget).

Here is my question. I'm looking to get as much as possible sound "proofing" and overall just the "best" solution for a simple ceiling set up. The general idea is stuffing insulation between the rafters (2x8s) and hanging some material on the ceiling to cover it up. I'm not really looking to put drywall up there as I've been told that'll open up a whole new batch of problems acoustically, and I don't want to open that can of worms.

I was recommended the use of Roxul AFB sound control material. Apparently this is about 3" thick-- but comes in different densities? I've been told it can get pretty "dusty" and I don't want a ton of that falling down into the room. Perhaps someone can enlighten me if I can get the softer-ish stuff and stuff that up top in the rafters, and then stuff another layer of more dense roxul afb below that, and then hang a material (recommendations of types?) from the ceiling.

There is also a few air ducts that are passing into the room. There are gaps near the ceiling/at the top of the new wall that need to be "filled in" by putting some dry wall up, but these ducts can't be handled like that. The idea for these was for the longer duct, stuffing it all with insulation in that space and then sealing it up with a long piece of drywall. The other duct actually has a vent, so the idea was to build a drywall box around it (after removing part of the duct with the vent) with Owens Corning 703 wrapped in material inside the box, then covering the rest of the duct that is in the room with a piece of drywall.

I attached some pictures of what's going on at this point.

Opinions on the whole thing are appreciated, but I think my main question is about the insulation for the ceiling. Two different densities of that Roxul AFB (if I was understanding that correctly and there is such a thing), and then attaching a material (specific type?) to the ceiling... not too thick as to let sound get through, but not a bunch of dust/insulation particles.

Any help/info is appreciated. Thanks!

[fabricaudio]

If i understood correct you dont want to put any drywall on the ceiling


You can stuff the ceiling with insulation and just put a fabric on top for decoration and to prevent the insulation falling over the room. It will not be ''soundproof'' but it will do the job. The reason drywall is used is to provide different density layers for the sound propagation in order to attenuate better. Yes there will be a lot of reflection from the ceiling if you put drywall, but again you have reflections from the floor and the walls, so the only thing you achieve is to have absorption in 1/6 of your surfaces. So you still need to treat with absorption the rest of the surfaces

My main argument is the ducts you have there, they had to be the flexible ones with the insulation layer in them. With these you have now you can transmit the noise very easy and you may even have some strange resonances in them from the music you play.



Nikolas

[tINY]

Build a plenum and keep the airflow down there. You don't want to stop the HVAC from getting to you, just stop the sound from traveling through the ducts.




-tINY

[nosebleedaudio]

Use softduct, I would never use metal duct...