ok im going to try and do my first amp install on my other car, im using some old sony amp i have laying around which is rated at
2ch:200w
4ch:80w

im only going to use it to power 4 speakers for the time being, and has 2 rca inputs. one labeled subs and the second labeled main. im assuming main is for speakers and the sub input is obviously for subs. question is, can i hook up a speaker rca input into the sub input?

head unit has outputs for front and rear speakers, so i was thinking running an rca from the front output to the main input on the amp and another rca from the rear output on the deck to the sub input on the amp and then wiring up my 4 speakers.

hope that made sense lol

 

The sub is probably an output for another amp. Your Sony may have a crossover in it.

 

I'd be willing to bet you could find the info you're looking for if you google the make/model of the amp. There has to be a user manual for it somewhere.