So my -db's I reported earlier were a little off not in the car just what I was telling you guys.
In the car I just needed to re-level match @ -21db to get underseats correct, heres what it reads :
[ all readings from driver seat ear level above center console ]
= Stock ( replacing with DLS R4's asap ) Center
= DLS 424
I will try a new calibration at lesser -dbs when the front speakers are replaced.
Currently underseats are level matched to the DLS Center.
I performed the calibration / sweeps in the method above with sub disconnected and x-over to OFF
and it appears to have made a big difference, I still havent pushed the sub as its new still.
I may still try changing the +/- polarity on the sub as well to see if theres anymore improvments.