When loopking at an amps pwer rating RMS manufacturers give a RMS power rating at 12V and 14.5V. Which one do I look at? What voltage does the car battery release to the amp?

 

12v is car battery when the car is not running

and the 14.5v is when the car running and the alternater is chargeing the battery,

so when ever you are setting up an install always have the car running, as the output from the amp is higher,

 

Thanks!