I am designing the build for a basement recording studio / music room.
Here’s a Google Drive link to a picture looking South into the 25.25′ L x 13.13′ W x 7.58′ H space:
The studio space is delimited by the West and South unfinished basement foundation walls and the steel support beam on the East side. This beam will sit about 1 inch outside of the East wall of the studio. Note that there are no foundation walls involved East or North of the proposed studio.
I’m currently developing the details of the design and costing the materials.
The thing that I’m fundamentally unclear about is what exactly should the wall assembly be for the two sides adjacent to the existing unfinished foundation walls, in particular to avoid the Triple Leaf effect (if that applies here) ?
I’ve got these materials at my disposal, to be deployed to best effect: 5/8″ drywall (multiple layers), Green Glue (1 layer), Mass Loaded Vinyl (1 layer), and all of Safe’n’Sound insulation, air, and 2x4s, as required. (I could also add 1 layer of 3/4″ plywood if necessary.)
Imagine standing inside of the studio space and looking out to an unfinished basement (foundation) wall (as pictured)…
What is the acoustically correct and best-STC-rated assembly to construct, from the room interior to the concrete foundation wall behind the pink insulation?
In order to design the proper barrier technology you must know two things. You must know the frequency and amplitude of the noise that is coming into the room and the frequency and amplitude of noise leaving the room. Guessing what barrier design to use without knowing the numbers, is a waste of time and materials. If you build something that you think will work, it propbably won’t and you will have to tear it out and start all over.
Point taken to be sure, yet in general I’m concerned about the “triple leaf effect” in the context of my build, where some kind of new wall assembly is to be built one inch away from an existing unfinished basement wall frame just in front of the concrete foundation wall.
Could degraded performance due to the triple leaf effect be a problem in this configuration ? (Whatever assembly results from sound measurements, it’s going to have some number of leaves.)
If it could be, then what distribution(s) of leaves among a new wall assembly and the unfinished old wall frame avoids the problem?
Am I not asking a two-part question simply about the essential physics?
With less abstraction: given that I’m looking to build a home recording studio , assume that sound across the audio spectrum, 20 Hz – 20 kHz will be produced, and in my case at a maximum level of 90 dB.
Noise from outside the proposed room is not significant.