what is a DD and juggernat subwoofer??

[bumpin_blazer]

i know you guys are all going to think i am an idiot for asking this but i don't know what 2 of the subs. i hear a lot about on this site are. i have never heard of a DD subwoofer before i got on here nor seen one also never seen a juggernaut sub or however that is spelt. you know anywhere i can check out some pics and specs on both of those speakers??

thanks

[audiolife]

http://www.ddaudio.com/ prolly the loudest woofer company going 1 15 did 170+ db
http://www.adireaudio.com/ check out the brahma
http://www.mmats.com/brochure/main.pdf the juggies

[RangerMan]

And man do they BUMP!!!!!!