So, you are lowpassing your rear co-axials at 200hz?? If that's the case, why not just unplug them and not use them at all?
He didn't mean to lowpass the components in front, he meant to say you should highpass them....somewhere in the 50hz-100hz range. And no, this is not something you're passive crossover will do.....this is something you need to do either at the amp or at the HU.
Well, by looking at req's post I'd guess that that's just the name they gave their internal 3-band parametric EQ. Just play with it and see if you can improve the sound.
Those are the center frequencies for each EQ band, where you can boost/cut the frequency as needed.