Re: To run sub using the built in subwoofer crossover or the one on the amp?
That's a good range of adjustments on the HU. I would set the slope for 12dB and lowpass to 63 or 80 Hz. With the level at 0 you'll have some ability to crank up a source that might need more bass.
1999 Buick Park Ave Ultra
Head Unit: JVC KWHDR720
EQ: Audiocontrol EQL
Front Stage: Hybrid Audio Technologies Imagine 5.25 mids, Morel Maximo tweets
Sub Stage: Boston G3 10", 0.5 cu ft sealed
Amp: PPI Phantom 900.4
Rear Fill: Boston SE953 6X9's