I installed a "Crunch" pzi 550.5 amplifier in my pickup. all went well it's currently set up to power 4 in cab speakers as well as a 5th channel to power the sub-woofer, an audiobahn 8"..
all works well but I have an alternator whine at low volume when the truck is running. I added audiopipe ground loop isolators to no avail.
I'm hoping there is a simple answer to eliminating this annoying noise.
All input is welcome.

thanks in advance,
Sparky.