Soundproofing an existing room in a rental loft

[heavymetal]

Hello,

I am new to the forum and am looking for help soundproofing an existing room in my rental loft (two year lease).

The will be used room for line recording and mixing. My next door neighbor plays the drums and I am as concerned about keeping "his" sound out as keeping "my" noise from reaching him. The tenant downstairs is a coffee shop with ambient noise/music during daytime hours. I am less concerned about them hearing me than vice versa. The aim of the raised floor is also to minimize flanking noise to/from my next door neighbor.

I am aware of the need to avoid a triple leaf system. It is also impossible for me to remove the internal gypsum layer from the existing walls.

Following are three possible builds for the floor and walls of my room.

The first does create a triple leaf system. I was hoping, however, that sufficient decoupling (from the existing floor), and the multiple drywall layers would offset the resulting STC loss:

http://amalgamatedsuperstar.com/room1.gif

The second build option plays on mass to raise the STC:

http://amalgamatedsuperstar.com/room2.gif

Is there a limit to the number of gypsum layers I should add to my side of the wall? I read that the law of diminishing returns may apply after 3 addtional layers.


The third option is a variant on the second one:

http://amalgamatedsuperstar.com/room3.gif



Which build offers the best STC? Is there a better way to build this room out?

Thanks!

[stereomaus]

Hi Heavymetal,

I have gone the DIY soundproofing route, and have the scars to prove it...If you can afford any of the rooms that you posted links for, than you have a good thing going already. The first room's structural design looks fantastic. If you are not an experienced carpenter or have friends who are...HIRE someone. I am assuming you want to play drums in the "new room" and that it is fairly large (at least 12' X 14'). Keeping drums out of your recordings will not be as difficult as keeping your bassier frequencies "in". The drone and/or rumble that you hear from an adjoining room can easily be gated and just as a ball park figure, at -35 db, it is only a problem if the players might be distracted and/or if you plan on recording very softly with acoustic instruments. The low cut on most mixers would eliminate any unmasked frequencies reaching you in any case.
a couple of building points:
- Do not put the walls of your room against the original walls of the room, this is also "decoupling".
- If you can place your final interior layer of meterial (Gypsum - whatever) at a non-90 degree angle this will help prevent standing Waves, phase cancellation, etc,...
- If this is a one-room studio than you can forget about recording live with multiple players unless the room is very large, and you have great monitoring options.
-Placing an acrylic drum booth in the room could make good live recordings possible (simultaneous multiple players).

Good luck to you!

[Rod Gervais]

Well, from a wall point of view the 3 drawing beat the heck out of the 1st one.

The 1st detail creates that dreaded 3 leaf wall with only (assuming from your detail) one layer on the other side of the wall - but even with 2 layers there - wall 3 is preferable.

BUT - i see some real problems with the floor details.

1st - you can't have a floor deck which is drywall - you will have to switch to densglas for the top-most 2 layers.

2nd - you don't indicate any info on the neoprene carrying the 2x4 sleepers - is this continous or simply pucks located in a particular spacing?

3rd - forgetting any wall loads - you are adding over 8 psf of dead load to the floors in your rental.......... and you really need a structural engineer to sign off that you aren't overloading this floor.

Typically a bedroom is designed for a 10psf dead load and 30psf live load........... living type rooms are 10 and 40psf (D/L)

But this depends on how old the building is - how much attention to detail the builder took - etc..........

SO begin there and then - once you know for sure you can carry the load safely........ we can give yuou more information.

Rod