Amp Hook Up

Okay never really did any audio shit before so this is my first time. I have two Pioneer 12in subs in the back with two Honda OEM factory speakers. Now I got a amplifier for free so I figured I might as well hook it up. But im dumb when it comes to this, someone help me out. Thanks

**Subs and Speakers are in custom box**

if you still have the stock deck, then u might want to get some line-out convertor.

If you have a high level in on the amp, just splice off the rear speakers and run those to yuor high leve in, then all you need is a power and a ground.