Yes the Monsoon system probably has equalization and crossover functions off the "amp".
Whenever anyone asks about LOC I suggest only one and that is from David Navone
http://www.davidnavone.com
In my experience of over 14 years, LOCs are almost always crap. Theres almost always noise or tuning issues- especially when inexperienced people install them. There should be a gain adjustment on the unit if its worth a crap- and that really needs to be set properly.
Given the complexity of the double gain (amp and the LOC) I suggest setting the amp gain to a bit over the half mark- not quite 3/4 though. Have the LOC gain ALL the way down. Set the radio to normal listening volume with a bass heavy song or a bass track. Then adjust the LOC gain from there.
Trust me brother we all have budgets. I carry an array of products to cover most peoples budgets and needs.