Haha, sorry, i really have no clue what it is about, i emailed alpine just asking how to wire up my sub.
they replied
"For your sub i would connect it for 4 ohm, that is the closest to the ideal you can get..... that will be a seires connection..."
Then i went on the alpine manual for my sub and there was an image with "jumper" like leads
I have no idea how to wire it up but apparently because its dual voice coil sub i have to do it differently, thats what alpine said anyway