Never heard of them before, and i've been trying to kinda get back into the whole car stereo thing lately. anyone that's gonna build up a car stereo kinda knows before hand what they wanna build, so i don't see a reason to want to change my sub impedance AFTER building my system, but that's just me. I don't think you can go wrong with a dual voice coil sub, they give you a lot of possibilities as far as wiring. Maybe they're just trying to market to people that wanna say they've got something different?