I have a setup for my system need some advise with. My head unit is a Pioneer DEH-P6200BT. It has setup menu for subwoofer and output for it. It has hi and low pass filters too. The thing is so does my amps. Is it better to leave the head unit in a neutral setting and use the amp settings or use the head unit to do the setup with. Also should both be used. I have one amp for front and rear speakers. and another for a sub in a band pass box. Maybe use combination of both?