mgam, try and experiment with the angle of your tweets it may reduce harshness a little sa pax side, if your not satisfied with the way it sound then set it back to original position, a little experiment might do good :D

correct me if i'm wrong you have a Pioneer HU with built in SFEQ right? 6450 or 7450??? if yes, instead of using the SFEQ function why not try to put the built in EQ to Flat, then adjust the 3band eq/bass&treble/xover to your likeness and consider also what it would sound sa pax side kasi paano kung girl ang sasakay tapos sakit sa tenga ng sound mo diba turn-off agad! :D

just my two cents bro'. :D