If im running 2 amps...1 for subwoofers and 1 for speakers....and also i need a pre-out for ipod and a pre-out for my tv and anything else i end up needing rca's for, how do i go about doing that. If i have 3 pre-outs on my head unit and need only 4, can i just split one of them, or should i use like a hi-lo for one of the amps?