Im thinking of putting 2 12's in my sisters car its a 2004/2005 corolla (not sure which) but i was just wondering would i need to upgrade my alt.??? or would it supply enough power to satisfy the 2 12's with a PROPER 1000watt amp??
I'm running 1200 rms with a 110A alt and no trouble at all. I ran a similar system with a 75A alt for a couple years with a little more noticable dimming, but still no major problems.
It's very dependent on the car, attn. to detail on the installation (good connections, ground), listening habits, etc.
There are people running 2kw with 100A alts w/o a problem, but there are people that have trouble with <1000w>100A alts.