JL XD400/4 question

Ok, just bought this amp last night for $200 and plan on putting under passenger seat, I currently have Kappa perfects component set in front and Kappa 6.5 coaxial in the back. I don't plan on putting in a sub cause I really like having that storage. My question is what is best tuning settings and wire routing for this. HU is AVIC X920 and I originally hadn't planned on an amp but the HU is working hard on the front speakers.

 

Run the 4 channels from the amp to the 4 speakers in your doors full range. Done.

 

Stock headunit?

 

Headunit is X920Bt

 

Agreed.

I'd say run the power wire down the channel under the drivers side door sill and mount the amp under that seat. Makes life easier.

 

Well I pulled wire today from battery and looks like under driver seat will be better. So how should I set the HPF and LPF for best sound.