How effective is soundboard for isolation?

[Guernica]

Hi folks,
Does anyone in here know how effective that brown sound board that comes in 4x8 sheets is for isolation.... as compared to 1/2" or 5/8" drywall?
...also, is there a particular frequency range that it dampens?

much thanks, Mike

 

[Rod Gervais]

Hi folks,
Does anyone in here know how effective that brown sound board that comes in 4x8 sheets is for isolation.... as compared to 1/2" or 5/8" drywall?

Mike,

For the money you get much better isolation with multiple layers of drywall than with sound board.

The only advantage that the sound board "claims" is decoupling from the structure - and (for my money) I get very nervous about the thought of having my only attachment for subsequent layers of drywall being the soundboard.

For lower frequencies - (which are the problem frequencies we really need to concern ourselves with) the greater the mass the better isolation - and drywall does the job real well.

If the application is to a single stud wall (drywall applied to both sides of the stud) you get good isolation with RC-1 (Resilient channel) and best isolation with hat track (metal furring channel) and RISC-1 clips (which are rather pricey).

If you are using a staggered (Or true double wall) stud assembly then there is no real gain through the use of RC.

I hope this helps,

Rod

 

[Guernica]

thanks rod,
...what im considering doing is actually putting a layer of soundboard over walls with 1/2" drywall on them. ...then covering the soundboard with fabric.
.....any thoughts?
thanks

 

[Rod Gervais]

thanks rod,
...what im considering doing is actually putting a layer of soundboard over walls with 1/2" drywall on them. ...then covering the soundboard with fabric.
.....any thoughts?
thanks

Mike,

Once again - for isolating purposes you'll get more out of 5/8" drywall than with soundboard.

So if that's what you're looking for (isolation) then go with the drywall - you can do a fabric wallcovering (commercial 54" goods) over that if you wish.....

Rod

 

[crankz1]

Greater mass of the walls will offer isolation, whereas rigid fiberglass or rock-wool will offer sound absorption of different frequencies (depending on thickness).

Wall mass/construction is for sound proofing (isolation).
Absorptive and diffusive materials are for room acoustics.

Check out John Sayers Recording Studio Design Forum for a ton of great information.