2500RMS?? runnin a 2000 watt amp at 12.5V...... I dunno the rep on that amp, but i'd be surprised if its puttin out more than 1500 at that voltage
think of it this way... your at 12.5... imagine -2 drops to 10.5... that diff. is gonna be about the same audible diff from 12.5-14.5 with a stong alt....
(someone clear that up for me)