So I got around to installing my new headunit (Sony BT-3000P) and powered sub (Sound Ordnance B-8PT). Overall, the install wasn't too bad (thanks for the help I got here). I was worried about running the power cable through the firewall, but it wasn't bad at all. I also have the Polk DB-651 speakers I'll be installing this weekend.

For now I'm trying to figure out how to best tune the setup, since both the headunit and the sub have similar controls. Because the sub will be under the passenger seat and not accessible, I would prefer to control everything from the headunit as much as possible.

The sub has the following settings:

Level - Min/Max
Bass EQ - 0dB/10dB
Phase - 0/180-degrees
Frequency - 80Hz/200Hz

My main questions are:

1. There is no option on the headunit to control the phase to sub. I'm not sure what this setting is for or what a good initial setting is. Any idea on where it should be initially? I'm assuming just leave this at 0-degrees?
2. For the other options, I can control these via the headunit. Should I put them all on the max setting on the sub and lower/adjust from the head unit, or should they all be set to the minimum settings?
3. The headunit has a low-pass and high-pass filter. Should these values be set to the same frequency, such as 100 Hz, or should there be some overlap (e.g. LPF at 120 Hz and HPF at 80 Hz)?

Thanks for your help!