check the JL site for the reccomended enclosure size and some box designs. They do say that it can be either ported or sealed, but I have always prefered the way subs sound in a sealed enclosure, especially with a sq sub such as the W6.
Any experience w/ a 12w6 in a box that size? Cuz that is WAY too big for that sub.
I have mine in 2 cubes @ 32 hz at the moment & that is too large. These subs like smaller enclosures & JL's recommendations are spot on. Of course this is assuming you bought a SQ sub for SQ.