Audio Systems: do i need a extra battery?, heavy duty battery, high output alternator

Question
hey i just bought a full stereo system for my 04 grand prix and was wondering if i need anything else. i got 2 12inch kenwood subs and 2 kenwood amps.my max power on my amp is 1800watts and than my max power on my subs is 1500watts. the rms on the amp is 500-900watts and than the rms on my subs  is 90-380. i planned on just tuneing my amp just half way.but i heard that if you dont feed your subs enough that you will blow them. i also bought a 500 watt kenwood amp just for my highs, 2 sets of tweeters,6*9,5.5s.that seems like alot of power, but dont know if its enough to get a 2nd battery. i dont want my car dieing on me, or start having car problems. i also bought a epicenter sound processor. wat do you suggest i should do about all that power.that i will be running. im always driving and love listening to my music well im always listening to my music, but i dont want it messing up my car. please help

Answer
With that many amps running you probably should add a heavy duty battery and a high output alternator.  Here is a good check:  Turn on all the amps and run some music  which is playing at the loudest you would ever run the system; making sure there is some good bass sounds running during this test.  Now turn on the headlights and see if they go brighter when you switch off the amplifiers.  If the get dimming of the headlights during music play you are overloading the car's system and you should beef it up.

The current required from the car electrical system by the audio reproduction system is a function of the loudness and mostly that coming from the subwoofer system.  It turns out that reproducing bass is a real power hog and takes very high current to drive them when heavy kicking and gut thumping bass is going on.

Best wishes.