I know that in car audio systems amps are used to increase power to the speakers especially the subwoofers but how exactly does it do that? If an amp is 1000 watts and watts is volts times amps than what is the amp doing to make the 1000 watts? Also in some cars that have systems that are sometimes 4000 watts or more how is the cars electrical system able to handle that kind of power? Any enlightenment will be much appreciated. Thank you.