ok so a 4 channel amp has a front and rear output that connects into the HU? i have been thinking about addind a amp to the speakers for a little while... i will need 2 rcas and amp and thats it?
Yes, you can get a 4 channel amp for your front and rear speakers if your HU puts out 4 channels. You'd need 2 RCA cables, speaker wire, power wire, and the amp.