My rear batt is isolated from my under the hood one. When the car is off the batt rest around 12.7v. When i start the hu, the amps power on. The voltage drop to like 11.5v for no obvious reason, even with volume at 0. If i put some juice into the amps, the voltage drop to 10v, car off. I guess this ain't good for the amp but they don't even shut off.
What could it be? Is it possible that my battery ground ain't great? I mean, when i put a little charge on the batt (amp at iddle) , i get a .8v drop. otherwise what could it be? is it bad for the amp to play in the 11ish without dropping too much ( not like 14v to 10v....)