I am currently contemplating mounting my centre speaker into my cabinet to allow my screen to come lower and to also please the Mrs. I am sure I have seen on some photo installs, some insulating materiel around the speaker's built into cabinets.(why do this) If this is correct what type of material should I be using? or am I best just leaving it clear in the cabinet. Here is a photo of what I have done so far, I do have some black speaker cloth to finish it off but I may use grey if someone can point me in the right direction. Thanks for any help.