Ok so I've started to build a custom box in my trunk and I'm using the space where the spare tire used to be. The bottom is fiberglass and top will be MdF board... The sub is an alpine 12" type r... The boxes volume is almost dead on with the specs for the sub. The issue I'm having is the port size and lengths... They say to use 1 round 4"x22" or 1 square 1.25x12x21" port.
My question is can I use to 2" ports at the same length as the 4" or will it not work that way?