Stereo receiver to avoid voltage drop

Thanks for all the replies. We will try to limit the bass (hubby is the heavy hand on this one). He will check out the wiring; should it be shorter and thicker? Or thinner for less resistance? I don't remember much from college physics. We will nix running wires from truck batteries also. Batteries are just a little over a year old brand new when we bought camper in 10/2012. Maybe another radio with less wattage? As I said, I would like one that has NOAA weather band and is more protected from our damp weather like a marine grade radio. What receiver do you all have?