I am planning to build a proscenium mainly out of hard wood. I am going to use grill cloth in front of the left, right, center speakers. I would like to conceal my subwoofer behind the proscenium, but I have a down-firing sub. Should I try putting grill cloth in front of the sub, or is this not an issue with frequencies in the sub range. Also if anybody has any other suggestions on designs to accomodate down-firing subs in a proscenium I would like any info you can provide.

Thanks