In in NY now, so I can't do anything else with it, but I can tell you that you have an oil leak. there's a spot in my garage.
Also, I never adjusted the Low pass xover, just the boost and the gain. turning up the x over will make the subs play a greater range of frequencies, so you'll probably need to then turn the gain and boost down.
<span style='color:gray'><span style='font-family:Courier'>1995 e36 3 Series RIP
1999 e46 3 Series BURN IN HELL
2000 MR-S Roadster= Current</span></span>