I have 4 alpine 6.5's, a clarion m303(18watts x 4 channels) and I want to add a subwoofer. I was thinking of buying a 8" or 10"marine bazooka amplified bass tube and placing it on the side of the engine compartment(by the battery). There's an open ventilation port right above the battery. Do you think this will be enough bass? Any suggestions or opinions? I don't want to cut any big holes out and I'm thinking this might do to trick.