Hello all!!! I'm new here and have a question. I have a 96 Audi A4 Quattro. It had a factory headunit, I believe it was the concert radio. This unit also to my surprise, had a stock 20 watt amp connected to the driver side rear speaker. I Purchased new door and rear speakers, brand Scosche Hd. 4" for the doors, and 6.5" for the rears. I also purchased an Pioneer Avic N1 on craigslist for 100!!!. installed it, had to run speaker wire from headunit to rears. Ok, so for about two weeks, all is good. Even had it hooked up to a Power Acoustik 1 ohm 2400-2 amp pushing some Infinity Kappa Perfect 12's. Then I hit a bump and sound crackled. Eventually it came back, but then one day, nothing from main speakers. However the subs still had sound. So I pulled the N1, and put in a regular pioneer cd player. Same problem, sound would crackle in and out only at high volume. So now I have the Avic N3, and same thing. Now I have checked and double checked my setup, everything looks to be good, nothing seems to be grounded out or shorted out. What can this be? I so tired of not having music that I'm thinking of selling the car!!! Sorry for the novel, but I'm so stuck... Also does polarity matter concerning speakers?