Forgot to mention, Ethan made it clear to adhere the Kraft paper to the rockwool with spray adhesive.
If bass absorbers work better with Kraft paper Jimmy, does using adhesive spray affect the rockwool negatively by closing some of it's porous nature?
Can you link to the article / forum page where Ethan is talking about this? I'm looking around but have found it hard to find as he's done a lot of stuff all over the web.