Leave it alone.
Two reasons, too many complaints about JL Audio reliability, as well as how hard it is to integrate a sub with main speakers. If you have it dialed in don't touch it!! :D
If you want to really dive in though, consider a miniDSP along with the appropriate measurement gear to help you get to glory.
Also, room acoustics matter. A reflective room, bad placement and big room modes should be dealt with.