I need help installing my memphis bass 2.2?

Hello everyone... I have this bass 2.2, i know how to do pretty much everything to install it, but i dont understand how it says connect the digital bass enhancer to the cars battery... my amp kit is installed to that so why would i do that? Then it says to do the same thing for the ground wire, which is also connected to my amp ... do i need another kit? Last time i had one of these things, i could of sworn he just connected the RC's to them, which i can do myself.. but im just so confused haha....