done with the build. never had a set of 15s but WOW totaly different sound. Very smooth and fills the truck when they are turned down on the EQ. My old ported 10's would make you sick (head ache, itchy nose, and ears) when turned up past half way. These 15s still move the same air without the discomfort. Not my best box build but funtional to use the center car seat tie point. The awkward extention on the top of the box is to keep people from recling the back seat on the speaker. To sum up: I am happy so far with the Re Audio SEx15s. Clean SQ and solid lows. Box net 2.13Cu and if i remember right 30.15hz and flat as hell curve. if someone will help with how to install pics i will upload.