Hope you guys can help me out here. I just got a excursion and want to a sub or two. Option are single 15" TC Sound 5200, 18" TC Sounds 5400 or 2 18" TC Sounds 5400. The max dem I have are 52W X 25H X 16 D might be able to push it to 18. 48W makes more sense but trying to as much airspace. Amp...