Yes they are d2
Their output compared to other drivers is often misunderstood, no they are not all out spl subs they are designed to be loud at low frequencies (54MM xmax). I had only 2k on each and they will easily take double that. I was only at 144db but that was at 29hz!
They will also work well sealed in small boxes. If I don't sell them then I will make an insane home theater sub out of them.
If you are looking to please a mic there are much better subs out there but if you want deep rumble the only subs I have experienced with this kind of output are the TC/Audiopulse ultras (and clones) and these.
The retail on these is 2000.00 but I got these for 1000.00 ea //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif