Cement board? It sure can add mass, right?

[Bryan316]

Has anyone used good ol fashioned cement board for building up layers of mass for isolation? It's quite dense and heavy, right?

I'm thinking of conducting this experiment for our vocal booth. Put two layers of this stuff, with green glue between, see if it works well, or if there's no improvement compared to fire rated drywall.

 

[jaygee]

I use it for building sound isolation boxes around my computers.
I line the inside of the cement board with fiberglass acoustic insulation and it works quite well.

Never used it in a vocal booth, but mass is always helpful in sound deadening applications.

 

[stevieb]

Related: I once had a very "bouncy" house. I put a cement stepping stone- I mean, the big, 18" X 18" size- under my vinyl turntable to control the bounce. It helped.