box for 12" L5
#5
That calculator is inaccurate (because of port end corrections), use the 12 volt's (which doesn't correct for the end of the port, do it yourself). Find the dimensions you can use for a sealed box, and then minus port area from it for actual space. I would do 2.5 cubes.
Subwoofer Enclosure Calculators, Fraction to Decimal, Parallel, Series, Port Length and Volume Calculators
Subwoofer Enclosure Calculators, Fraction to Decimal, Parallel, Series, Port Length and Volume Calculators