Quick question about a box for these subs. American Bass Specs site 2-2.3 cubic ft per sub for a ported enclosure. I have a box I wanted to use. I didn't really want to take the time to build one right now. The one I would be using has 2 cubic ft per sub and is tuned to 30hz. the 2 cubic feet is before displacement though. Is it still going to be a pretty good box for these? Would it help to throw in some polyfill? Should I try around 4lbs of polyfill? I don't remember the formula but I was thinking it is like 1-1.3 per cubic ft Thanks