I spent most of the weekend scouring message boards on the subject. I have heard postive on both. SQ is my priority, and I've heard that even slot ported (the JL H.O. Wedge), this sub has no noticible loss in SQ. I'd really like the best of both worlds, should I go for ported? Is there much volume difference between sealed and ported for this sub? Part 2 is I can't find anyone who carries the H.O. Wedge. Sure they offer to order it from JL for me, but then I'm full retail at $899. I can get the sub alone at my local Tweeter for $650, so $899 is a rip. I don't trust a custom made ported one as I don't want it to end up sounding sloppy, but a custom made sealed I won't have that risk. So I guess my question too is maybe then should I just go for a sealed one? It will go in my Suburban and run off my 500/1 - which is currently pushing a mediocre Polk MOMO.
if you don't want to pay for the official JL box, the 12W7 does offer the same box specs on the JL website. Just have the box built to spec, and use 3/4" MDF, cross-braced internally and reinforced. That's all you need and it should sound just as good as JL's box if it's built by someone with experience.
the difference between sealed and vented is about +3dB up for ported.