Help understanging room within room construction

[Megaman9]

I am planing to build a room within a room (not myself), so 4 new double stud walls and a ceiling, in the middle of an existing room, but I still don't understand a few things probably due to lack of knowledge in basic drywall framing.
The room is going to be used for playing electric guitar and bass (one or two players)
Please see drawing attached.(new walls in red) The existing floor and ceiling are both concrete.

So far, as I understand it, the framing of both new walls are attached to the existing concrete floor
and just the outer wall is also attached to the existing ceiling. Does that mean the inner wall is only supported by the floor? pretty sure I am missing something here

My wall plan is 2 5/8 sheets with Tecsound SY50 between them on each side and 2 layers of insulation.(air gap)
How do I get the ceiling to have the same level of TL? I suppose I need to have double ceiling, but I still don't understand how to construct it.
Can the bottom ceiling rest on top of the inner walls without being attached to the existing ceiling or outer walls?


Any help would be much appreciated!

[John Steel]

Hello & howdo' Megaman9?

I am planing to build a room within a room

This is the best way to achieve good isolation on a budget.

so 4 new double stud walls and a ceiling, in the middle of an existing room

Maybe I have misunderstood you but this implies that you are considering a 3 leaf system which, although sometimes unavoidable, isn't ideal.

The room is going to be used for playing electric guitar and bass

So low end isolation will be critical - the low 'B' on a five string bass is approximately 31 Hz.

The existing floor and ceiling are both concrete.

Excellent!

. . . the inner wall is only supported by the floor? pretty sure I am missing something here

. Don't feel bad, it takes a long time to design a studio - it took me nearly three years before I was ready to start building. There are all sorts of things to consider, calculations to be made, techniques and principles to apply and it takes a while to learn about them. No two projects are ever exactly the same but there are general principles and best practices. The good news is that you've joined this self help community which has a wealth of information that's relevant to you. Try using the search function to sift through the posts and topics. I'd be very surprised if a member hadn't already tried to build a similar project.

My wall plan is 2 5/8 sheets with Tecsound SY50 between them on each side and 2 layers of insulation.

I suspect there's a better way to get the isolation you need - difficult to say without more information.

How do I get the ceiling to have the same level of TL?

Make it the same density as the walls.

Can the bottom ceiling rest on top of the inner walls without being attached to the existing ceiling or outer walls?

I'm guessing that "bottom ceiling" refers to what studio designers would usually call the inner leaf ceiling. If so then it absolutely mustn't be attached to the outer leaf ceiling or your isolation will be compromised. Also, you must be certain that your inner leaf ceiling will support the weight of the insulation that you are going to load it with. I hired a structural engineer to help me with my design and I recommend that you do too!
Lots to think about, but you'll get there! Don't be in too much of a hurry to start building and be sure to read these two books if you haven't already: ‘Home Recording Studio: Build It Like The Pros’ by Rod Gervais and:
‘Master Handbook of Acoustics, Sixth Edition’ by F. Alton Everest, updated by Ken C. Pohlmann.

I look forward to seeing your design developing! Best wishes, John.