Question on Rockwool Density

[kraskland]

So I've been making traps using Rockwool Delta 212 insulation. I've finally got specs on the stuff and it turns out to be 40Kg/m3 (2.5lb/ft3) which is less dense than what I thought it might be. The early reflection and bass trap for behind the speakers are 4-3/4" thick. Is this sufficient or should I make the traps thicker or replace with a denser material (if I can find it)?

I had also planned on making a back wall trap of 7" thickness and superchunk style traps with a 35" face. Will this stuff do?

[Ethan Winer]

I'm sure that will be fine. Density matters, but as the panels are made thicker you can get away with less density.

--Ethan

[Weasel9992]

Originally Posted by kraskland

So I've been making traps using Rockwool Delta 212 insulation. I've finally got specs on the stuff and it turns out to be 40Kg/m3 (2.5lb/ft3) which is less dense than what I thought it might be. The early reflection and bass trap for behind the speakers are 4-3/4" thick. Is this sufficient or should I make the traps thicker or replace with a denser material (if I can find it)?

I had also planned on making a back wall trap of 7" thickness and superchunk style traps with a 35" face. Will this stuff do?

That'll do just fine. It's just a little bit less dense than what we usually use for those areas but not enough to make any real difference. 4-3/4" is great for the reflection points and front wall. 7" traps sound great for the back wall. I think you're on the right track here.

Frank

[elmolemon]

If i got it right, it's not just about the weight but also about the flow resistance (not sure if its the right word in english, but its: kPa · s/m²).

I plan to use Rockwool Sonorock (german rockwool), wich has: r ≥7 kPa · s/m²

Would that be a good figure for 8-10" absorption panels?

[kraskland]

Thanks Ethan and Frank, that's reassuring to hear. To be honest I was getting a little bit worried that I'd have to redo these things. I wish there was more choice for insulation around here.