Wow - no comments for a while - great thread. I have been progressively installing more and more Rockwool-based traps (modular and corner DIY supechunks. I was beginning to be worried about it - o somewhat more reassured.
Q: Will putting foam in front of (or layered onto) these Rockwool traps in the corners do any harm, sonically speaking ? It would seem they would contain the loose fibers better (currently covered with light fabric). They would also look nice and, finally, I have left overs laying around from my high frequency treatment duties I could use. Keep in mind as I ask - my goals is indeed a rather dead room (it is small). Maybe the extra 2" of this foam material would actually marginally help the low end that the Superchunks were put in place to tame ?
Thanks in advance