Rockwool broadband absorbers

[Charles F]

Hello studio lover's,

I recently moved into a new house and decided to dive in the realization of a little acoustic treatment for the room dedicated to my home-studio, which sound horrible. My choice turned toward broadband absorbers, what seems to be the easiest/cheaper solution to get correct results in bass/mid frequencies.

To build them i used Rockwool MB Rock 55kg/m3 with a wood frame and cloth fabrics as you can see in the pictures (the fabric is fixed tight to the wood on both sides with a lot of tacks). The sonic result is quite impressive, especially for someone who always work in poor acoustic conditions like me. I plan to hang 3 of them on the ceiling corners to increase efficiency.

The problem is that it's feel like i cannot breath correctly since i put them into the room. There is also a strong smell which is exactly the same since 5 days despite the many hours of hard ventilation with every doors/windows open in the first floor.

Based on what i read on different forums, i can see that some people use polyfiber or plastic as a second cover but the others don't seems to have any problems without ?

I wonder if it will really solve it... I was about to take off all the tacks (1200) to add the second cover but i don't want to make any mistake, that's why i'm looking for some advices.

Here is the pictures :

[Soundman2020]

It might be the specific brand of mineral wool that you used. Every manufacturer has its own method and formula for creating the binder that holds the fibers together, so perhaps yours uses some chemical that others don't.

You might need to wrap them in plastic, but that would change the acoustic response: they would no longer absorb the high-end of the spectrum well. They would still work fine for the low-mids, and part of the high-mid range, but the top end would suffer. However, that might not be a bad thing, since many small rooms get over-absorption of the highs anyway. It's worth trying.


- Stuart -