I am able to fit a 32 x 15 x 18 box in my car. I would like to build a custom ported enclosure. I am going to run either a sundown 1500 watt sub or 2 750 watt ones. I know that cone area significantly increases sound but also iI would have to make a larger port cutting down on my usable cubic feet or increase my tuning hz. I would like it tuned at around 32 hz. any recommendations on what I should do?