Rockwool Acoustical Properties

[Kre8]

Hi there!

I would like to get a professional opinion on these Rockwool materials.

I am building full corner bass traps and also panels to fix on the wall.

The materials listed in the image below come in 50mm, 75mm & 100mm thickness and are 1200mm x 600mm in size.

I’d be grateful to anyone who could advise me on which of these materials is best for sound absorption.


http://i61.tinypic.com/fjnj9g.png

Many Thanks

[Bob]

Strange that the test results don't list the thickness -- without which the results are useless.
Nonetheless my guess, from the coefficients, is that they are testing 2" thick material, and that looks about normal for that thickness.

Please see
http://www.bobgolds.com/AbsorptionCoefficients.htm
Basically, anything with similar coefficients to Owens Corning "703" is just fine, including rockwool.

[Kre8]

So it seems the 100kg/m3 is the closest to the 703. Although at 250hz there is quite a difference;

Rockwool 250hz = 0.66
703 = 0.86

Do you think this is still ok to use or should I keep searching for something closer?

[Yannick]

You should use low density for the full corner traps.
Higher density for the panel traps.

You could play around with this calculator:

http://www.acousticmodelling.com/porous.php

But then you need to find a way to convert these densities to flow resistivity.
I think someone around here has a list to get a decent estimate ?

[Kre8]

Thanks for the link Yannick.

I have come across some 60kg/m3, would you say thats a good all round density for panels and the full traps?

[bert stoltenborg]

http://www.homerecording.be/forum/t28576.htm

Always keep in mind that differences are marginal

[Kre8]

Wow! thanks Bert. I will post some pictures soon while i am building the studio! Exciting times!

[bert stoltenborg]