Cork is pretty useless but professional absorbtion/diffusion panels can be covered (disguised) with almost any open-weave cloth which, otherwise, passes the PAF.
IMHO, none of the other tweaks is worth spit (to quote a more public speaker) in this context without some room treatement.
Kal
IMHO, none of the other tweaks is worth spit (to quote a more public speaker) in this context without some room treatement.
Kal