I have a Denon 4802 amp with Sonance speaker system but no subwoofer. I have an old wooden chest 38"x16"x16" that I want to place under my projection screen and think I could use this as a subwoofer cabinet. It's 3/4" oak construction and is very solid. I'm thinking about putting one or two 12" speakers in it firing toward the rear, a few inches from the wall. Any suggestions on how to port this (if at all) or what speakers to get for it? Or is this a really stupid idea?