is it possible to directly hookup an Ipod/mp3 player to an amp that's powering speakers and sub without having a headunit? I dont see the need for a headunit if you have an amp and all u listen to is your Ipod/mp3 player. it seems simple enough to do. all i need are some Y adapters for the RCA's and an RCA to 3.5mm jack wire. have anyone done this before?