hi i bought one 12" sub Image Dynamics ID12D2 V3 i am going to power it with a rockford 250.2 in bridge just for one sub at 4ohm how can i make the box is going to be put on a F-150 2005 regular cab (no seats in rear) so enough space i like to hear latin music, rap and reggaeton i guess that it has to be sealed do i put poly fill in it cubic feets? etc