When looking at amp power specs, 2 values are often given. One is the power rating at the normal 12 volt, the other at 14(or 14.4) volt. The 14 Volt rating is always higher. How do you achieve the 14 Volts? Is this the result of a capacitor being used? Or is this the rating if your HU has powered RCA outs. I think my Pioneer HU has like 2 or 3 volt RCAs which would account for the amp recieving a stronger signal. Any help please!!!

 

Your battery produces 12v. Your alternator produces 14.4v. So voltage the amp sees depends on whether the car is running and charging the audio circuit or whether the car is off or the audio system is isolated from the alternator output.