Lol, come on guys are concepts really that unknown of a brand? or should i say a off brand or something???. every one i ask or called about trying to find specs . THEY HAVE NO CLUE . was depending on you guys , a lot of you here know your car audio like the back of your hand. i just cant believe no one has any info for me. anyways im really happy with them i had 2 12" type r's and the 3 12" concepts blow em out the water by a long shot even tho they are in a really small sealed box, im sure if i build a box to spec they will be x5 louder.