15" alpine type R -port tuning frequency?

[Slimsta]

diagram of the box with all the numbers in inches

i used this website http://www.the12volt.com/caraudio/boxcalcs.asp#por

to calculate the volume and go around 4.1 ft^3

what LP and HP Frequency should I set my amp on?

i need to know the port tune

my sub is brand new, just got it like a week ago. it Alpine Type R 15 inch 4 ohms subwoofer. my amp is JBL GTO7001.

i got the box ready like this from some guy.. he said he made the box