Hello Joseph and welcome to the Cow Audio Forum.
What you want to do is not trivial.
You pose an interesting challenge that Bruce (as he usually does) has analyzed beautifully. Yes, Density is your friend, but you’re missing a point. It’s not just one density. Effective isolation requires Density-Isolation-Density. (DID). (or even more DID layers)
I like the idea of a noise abatement wall, but as Bruce notes, a lot of the LF stuff travels through the ground, to your foundation and into your space.
ANY compromise in the isolation and you’re screwed. One facility I know of in Arlington, VA is right on the street of a major thoroughfare. There was you basic sidewalk and then the building wall. On the other side, literally, was a suite of audio control rooms and VO booths. I was impressed by how quiet it was. They said their walls were resiliently hung and they had SEVEN layers of drywall.
Another facility in N. VA was built into the ground floor of a (then) contemporary office building. The first floor was vacant and had taller ceilings. They built the studio facility on that floor. The spaces were arranged around a machine core room. Each space was floated and none of the spaces touched each other. This was something the owner really had to bird dog because the construction company simply didn’t get that isolation was that important. It is.
At Flite Three in Baltimore, one of the best isolated facilities I know of. (Studios floated on 4″ of cork, separate building for HVAC compressors decoupled from the main facility, huge over-sized ducts, block and brick construction, three studios), we were comparing mics one day. They big had Urei 813 (I think) soffit mounted monitors. During the test, we noticed that occasionally the woofers would visibly throb or wiggle. No doubt, it was from the occasional truck or bus passing by on Cold Spring Lane, at least three hundred feet from the audio building.
So, again, your job is not trivial. One trick I did pickup on for heat, recently was a facility in which they imbedded pipes into the concrete floor and created a radiant floor system. I worked in that facility in winter and it was very comfortable, with no noise from the floor, and no HVAC fan noise.
Best of luck with your process. Please do keep us in the loop.
Regards,
Ty Ford
Cow Audio Forum Leader
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