I dont know. But I am about to get 2 12's that are X124 single voice coil. I hear that they are pretty good for the money. And also they have a BIG MAGNET, a 103oz magnet to be a 500RMS. Because my friend has 2 AudioBahns and have a 60oz magnet and say that they are 500RMS, BULL. The Xtant X series require alot of power, thats what CarToys told me.