So I'm looking at the JL a4300 and it tells me that at 12 volts it puts out 45 watts @ 4ohms. Then at 14.5 volts it puts out 70 watts at 4ohms. I noticed that the drawing of the side of the amp has a switch that has low or high input voltage, but I don't understand. How do you know what voltage your amp is getting? Or is that even what the voltage means? I don't know. Enlighten me please. I may be dumb so go easy on me if the answer is obvious.