I am looking to purchase either a 10" or 12" sub for my boat. Right now I have the Pioneer DEH-6600 (deck) running 4 6.5" Sony marine speakers and have my old RF 300.1 to power the sub. I am wanting a downfiring configuration so that the sub does not get too wet (if at all). It will be in a low traffic area too. Does anybody have a program that would show me the best size/dimensions to build a box for this? It needs to fit in a space that is 15"W x 12"D x 14"H What are your thoughts OT? Cliffs: I am looking for a relatively low budget sub (that will match the amp well) and a downfiring box that will maximize its output. thanks in advance guys.