I really like this sub, more so than the D9 just cause it does sound good, it does get loud and its great price wise. We installed a pair of 12 inch D6's in a Blazer for a friend/customer. Pre fab ported box, 1000.1 D6 amp.
At a local show this weekend, we held a just for fun SPL competition, the Blazer did a 148.6, it was pretty good for what it was. We sell a lot of those subs, they are great and of good quality.
And do us all a favor and send them more than 600 watts, they can each handle 1000 watts RMS.