so on sunday my car was running good until i tried to start it up and it cranked a little bit and just died so i had to push start it. next thing you know im driving home and i see my radio flickering on and off. then later on i turn on my headlights and my whole speed gauge just dies. so i stopped at my cousins house to take out battery and took it to autozone and it had 1 volt in it so i had it charged and i made it home but i was wondering is this an alternator issue or something else? (btw i just put my subwoofers in) would that cause a problem?