Wow, those Dcon's are getting a lot of love. Anybody meter these subs for spl? Do they prefer sealed or ported? Finally, how would they stack up against say a JL w6v2, Alpine Type R, Dayton HO. I have a Rockford Fosgate Power 1051s rated for ~ 1100 watts (bridged @ 4 ohms) perfect for a d4 pair. I guess I'm not sure but how loud is 300 watts?

Wow, those Dcon's are getting a lot of love. Anybody meter these subs for spl? Do they prefer sealed or ported? Finally, how would they stack up against say a JL w6v2, Alpine Type R, Dayton HO. I have a Rockford Fosgate Power 1051s rated for ~ 1100 watts (bridged @ 4 ohms) perfect for a d4 pair. I guess I'm not sure but how loud is 300 watts?

Yes they get a lot of love, they deserve it. Answers to the questions in the order they were asked: I have no idea if anyone's metered them for spl purposes, I don't think most who've bought them intended to use them for that purpose. Ported is generally where they're happiest, though they do quite well in sealed enclosures too. Stack up how? Output, accuracy of reproduction? They sound great, tight and quick when they're supposed to be and brutally deep output when it's called for as well. As about as well rounded a sub as one can get. I would imagine that the subs you listed would likely at least slightly outperform in output at full power since they're all rated at higher power handling. 300 watts is irrelevant when it comes to how "loud" as the enclosure it's installed in and the vehicle it's playing in would have more effect than just the sub that was being used. Just as a gauge, my sister's single 12" DCON in a 2.25cuft ported enclosure tuned to 33hz on the sub channel of a Hifionics ZXi8010 (rated 300wrms@2ohms) gets loud enough to have most everyone who listens to it disbelieving it's a single 12 and often ask to see the back of the enclosure because they swear there's more subs than that in there. It's loud enough for me to honestly say that if all I had was that single sub I would be very happy and would rarely be seeking more output.

Well for the price I can't go wrong. I wish I would have ordered them while they were on sale for less than a $100.00. They may be a perfect match for my Focal 165 vr 30's up front. My own nice little "sound quality" system!!!