Accoustic Vs Thermal

[deuce22]

Hi.

I am looking for some clarification.
Does acoustic insulation have different properties over thermal insulation.
I’ve been told, that for soundproofing, it is all about density.
If an insulation that is marketed as accoustic, weighs 10kg m3 and an insulation that is marketed as thermal, weighs 15kg m3, will the thermal insulation provide better soundproofing?

Thanks.

 

[JohnMo]

Main difference is stiffness, but that is so it doesn't slump after installation. Most acoustic insulation is in walls. The thermal insulation for lofts is really soft and would slump over time.

[deuce22]

So would a heavier insulation, whether it was marketed for thermal or accoustic, have better sound proofing properties?

 

The plasterer has just told me that he uses standard boards, but doubles them up, rather than using accoustic boards. The double standard board gives better density and is also cheaper.

 

I just want to understand if density is the main requirment for sound proofing.

 

Thanks.