How do you guys tune your subs? I'm struggling with very low mid (higher low tone, around 200Hz ish) definition. High crossover setting seems to clash with my under seat woofers and make things flabby and ill-defined. I seem to be happiest at 50Hz crossover with lower gain. Just wondered if anyone has any tips/tweaks before I start replacing more speakers... Setup: BMW NBT head unit, stock under seat 8" subs, Focal 4" mids and 1" door tweeters, Rockford amp and 10" non-ported sub.