Basement Mix Room With Concrete Walls

[Muscly]

Hi all,

I am building a mix room in my basement and require some noise reduction too and from the floor above.

The room will be located in a corner which has 2 concrete walls.
Ceiling will be hung from clips and hat channel.
The floor is concrete foundation (not floated)
Interior walls will be on the concrete foundation.
Typical double layer 5/8 drywall construction with green glue.

Question:
I have been looking at inside-out walls to maximize space/treatment and was wondering if there is a way to seal up the ceiling and interior wall leaves without the need for drywall on the concrete wall sides. I don't require any extra isolation going in/out of the building. Would a strip of MLV (or some other method) in-between the drywall edges and the concrete with sealant be a way of achieving this and without any risk of moisture getting into the drywall? I am not too worried about some LF travelling through the concrete. Is the drywall a must for symmetry?

Thanks to everyone that supports this amazing resource

[gullfo]

sound energy operates in 3D. so if you can use a single mass wall (the concrete ones), then create the framed walls and ceiling to have approx the same mass or use a pair of walls to achieve a similar level of isolation. more likely - just frame out a room within a room using the inside out approach. more even distribution of isolation for the inner room, and likely better symmetry for critical listening.

[Muscly]

Ok, how small of an air gap can I get away with with inside out boarding near concrete? would an inch with insulation suffice?

And some attenuated LF will make it through the boarding and reflect back off the concrete but be reduced by the boarding reducing the imbalance of lesser dense interior walls?

Thanks!

[gullfo]

i would stick with more density on the interior walls. and for the air gap - enough to get some wall insulation into that space - so you might need 2" to get some R11 (slightly squashed) in there.

[Muscly]

Awesome thanks.

It seems like 2 layers of 5/8 type X on the interior side would not even come close enough density to match the concrete side. Any suggestions?

Since this a mix room, is there a frequency trade off point in the omni low end vs imaging where trapping more of the LF in would be making things worse standing wave wise vs imaging? Also factoring in my bass traps wont be very affective sub 100hz. Should I aim for density to improve imaging as best it can be above say 100hz?

I am currently working in the middle area of a basement with a single layer of drywall on 1 side and its surprisingly not as bad i thought it would be. front wall SBIR and ceiling is much worse.

[gullfo]

as always, it will involve compromise unless you have the budget. you might need 3x 5/8 on the non concrete wall side + 3x on the "exterior" mass wall adjacent to that to sufficiently mimic the response side-to-side in the room.