is 140kg/m3 Rockwool too dense for bass trapping-Acoustics Forum-Acoustic Fields Forum

Hi all,

I just had my garden studio built and the builder used Rockwool RW6 (SL9080) for insulation (keep me toasty in winter) which is a dense (and heavy) 140kg/m3.

I have a load of panels left over. I was going to use them to make 1200mmx600mm rectangle bass traps for corners, real wall and first reflection – as I had done in my previous studio (I had over two decades ago … been a while). I had always assumed the denser (as well as the deeper/thicker) was the way to go.

However, having spoken to a few commercial acoustic treatment companies their opinion is that anything over 60kg/m3 in density and bass waves won’t being able to penetrate easily and that is why they only use the 45kg/m3 in their panels.

In my old studio I seemed to get good results with the 140Kg/m3 in a room that was 11ft by 8ft by 7’6″. But then, the monitors I was using were only capable of 48hz and a SPL of only 100. My new Eve Audio 3070 are a different beast altogether – going down to 35hz and with a 120spl plus this room/shed is bigger 13ft by 10ft by 7ft.

I could just go ahead and make up the panels and “see”. But then, I won’t be able to return them unused.

So my question is …is the 150mm of the 45kg/m3 AW45 (SL9020) the way to go rather than 150mm of 140kg/m3 (all other factors like air gap being equal)?

Many thanks.