bad source?

i have a 2002 toyota camry with 2 12 inch infinity 1252w's and a crappy motorjoy amp which im going to replace real soon. for now im using the factory radio and whenever i get some cash im gonna upgrade it. for the source im using the back 6x9's or whatever size they are. and for some reason my back speakers will go out, i can jam it all day and out of no where my back speakers will go out and my subs go out with it, my brother said its wired to the clip so the sub should still play without the back 6x9's but they don't and it will either just go out or it will make a loud buzzing noise real load and constant. any reason why my back speakers are going out?

Sounds like your head unit is shutting down.  How is the sub amp connected to the head?Support the12volt.com

it is not we are using the back 6x9 speakers in the back as the source for the amp. its because i still have the factory radio and we didnt want to risk cracking it unless we were sure we were gonna replace it.