soundproof bldg

[bb29510]

just thinking, what would it take to make a sound proof building, like a little bldg in the back yard. a music room so the neighbor wont complain, a man cave.

oh I would never do it, just wonder what type construction it would take, Coneco box covered with dirt maybe, concrete wall?

 

[billconner]

Block would be the economical choice, with lots of attentions to details and penetrations. A poured concrete roof deck would be first choice, but a simpler framed roof with a heavy (double 5/8" gwb) ceiling resiliently hung would be pretty good. Grout the block.

Now, want it perfectly isolated, two of those, one a couple of feet inside the other, and the inner one sets on big rubber blocks. The Four Seasons theatre in Toronto is one of quite a few theatres that is like that, but that is to keep noise out. Pretty amazing to tour through that interstitial space.

 

[Spud McGee]

Yep. Just something that sounds couldn't easily penetrate.
Some sound waves passthrough air easily. Some pass through the ground and solid walls better. By having the "box within a box" model, you have the solid walls that help stop the sounds that don't transmit through those well, and you have the air gap that stops the sound that doesn't transmit through that well.

Not to be confused with the other type of soundproofing, where people put foam and panels all over the wall. If you are wanting to play loud music inside a concrete box, the sound will be bouncing off your walls like crazy. This is where the foam and acoustic panels come into play. Dampening the sound that is bouncing around inside your box. They do little to help sound that escapes to outside your box, unless there is a path like a door and a hallway.

 

[Fix Until Broke]

Look up anechoic chamber

But as others have said above, a box inside of a box with no flat/acoustically reflective surfaces.

Ones used for sound testing of really quiet things will have ambient noise levels in the 10dB range - They're eerie to be inside of and can be disorienting.

These will be rooms 30' cubed, completely isolated on springs or airbags, 24-48" of fiberglass triangles on all surfaces, floor is perforated steel with same fiberglass below.

 

[Stuart in MN]

My former next door neighbor had a commercial recording studio in his house. It was basically a stud frame box inside a box, with the space in between the two boxes filled with sand. (Actually, since the studio was completely inside large room in his house, it was technically a box inside a box inside a box.) It worked very well, we're near a busy street and you couldn't hear a thing inside.

Getting off topic, but there's an anechoic chamber at a place called Orfield Laboratories in Minneapolis that's recognized as the quietest place on earth; the sound level inside is negative 20dB. It's interesting to read about. https://www.atlasobscura.com/places/orfield-labs-quiet-chamber https://www.orfieldlabs.com/

 

[ycgoat]

I have seen sand filled block walls, foam inside and outside the walls, and special CMU sections that had some kind of insulation and air gaps built in. I have not seen any as they were being built. The special CMU walls are enclosing large compressors used for cryogenics.

 

[billconner]

the sound level inside is negative 20dB

It would be useful if the article mentioned the reference or scale, since dB is basically always a reference to something which varies. In my work, it was generally to 0 energy, and threshold of hearing is considered to be around 15dB.

 

[Denwood]

Making it quiet at higher frequencies is pretty easy, but the low freq isolation is where you spend your money.