is there something wrong with my car battery?

Wednesday, August 11th, 2010 at 4:08 am

i have a system in my car i have 2 12 kicker cvr hooked up to 2 channel amp and infinity speakers hooked up to a 4 channel amp and i have a capacitor .. whenever my car is idling or i come to a stop the bass will hit then cut out and my speakers dont sound clear at all .. but as soon as i rev the engine or take off it sounds perfect . do i need a battery ? or an alternator? i dont know whats wrong? please help