Ok, so after last summer, I decided that the subwoofer just couldn't keep up with the rest of the stereo. I had a single 10" 500RMS watt in a ported box, but you just couldn't really feel it. So I had a local stereo shop, Grand Prairie Audio, build a custom box for me, in the section that used to hold the weak ass cooler that came with the boat. I wasn't using that tiny thing anyways, so it made perfect sense to put the subs in that spot (under the passenger seat). I had them put in 2 JL 12W3v3's that I had just got. They built the box, and put a vent in as well. They also made my front vent match the new one that they put in. Then I added a JL HD1200/1 amp to power those things. The Sub is ran off 10ga wire and the amp is wired 2ga. This thing is slamming now! I don't care where you sit, on the bow, or on the swim deck, or where ever, you'll feel it...and that's with the bass only half way up. Here are some pics. The box is kinda hard to see cause it's covered in black carpet and fills almost the entire area. They had to cut the flooring out to give me some clearance for the bass excursion, and the whole thing was more than worth it. Big props to GP Audio. This is the only part of the system that I didn't do myself. Oh, and i mounted an amp rack to clean things up as well.