Thank you all for the replies. Gearslutz and it's members are always there with the right answer
Just went today at the local store where I found pretty much all the stuff for
building some rockwool panels. Let's say that I will build them as DanDan said,
it's ok to use 40 kg, density ones or should I order from Internet the 60 kg density ones?
At the store the only have 100kg and 40 kg density, wich one is the optimal for absortion and bass trapping?
And since I read pretty much everywhere that rockwool is far better than fiberglass foam why companies still sell foam, does rockwool tend to have problems like moisture and deformation? Anyone heard differences between these two?