ey guys,
i'm missing some mid bass in the car and hindi ko na ma-compensate with my eq. i have 4inch seps in front (due to limited space) and 5inch coax speakers at the rear - both are mb quart and are powered by a decent 4-channel amp. i also have a free air blaupunkt 12" sub (tama ba term?) at the rear na dumadaan sa crossover.

i don't have any plans of buying any more hardware since hindi talaga ako audio guy (napasubo lang), i'd rather spend on performance...

my questions are:
1) apart from tweaking my crossover to get mid bass, can i get better low and mid bass if i box my sub?
2) what type of sub box?
3) how much would this box cost? where?
3) can i set it up so i can remove my sub box if i need the trunk space?

pasensya na sa dami ng tanong. thanks in advance bros!