ok im planning on putting in 2 10" visonik subwoofer(and eventually changing them) and putting in another 10" audiobahn subwoffer and a 1200 watt amp is that to much amp power for my scion? will it drain the battery to fast?
It will work if you run some good wire. What often happens is the alternator is not that big on those cars, then you drop down to 12v of battery when you draw more than alternator can make. After that it will start to kill the battery, dim lights, etc. Also you get less wattage at 12v than 13.8 or whatever the alternator is. I'd say try a 1K with good wire, maybe a better battery if it is small or second one, and get a class D amp they take less power. If you max it out and run into those problems, you will have to let off or figure out what to do about it. You can always go with less power and more efficient subs and still get some volume out of them.
I was testing a 1K class D amp on the bench and it took nothing to pull my fully charged 1K cca boat battery down to 10v. It only has a 2a charger on it.
I would also recommend using all the same subs and in same box or same size boxes.