Its all your preference.
A ported box I would set the Subsonic ~25-30hz range
sealed I wouldnt set it.
High pass I wouldnt use for a sub, you wont like the lack of bass //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif
Low pass I like mine set low...in the 50-60hz range. Set it where you like it from the 50-100hz range.