That's funny.....I got alternator whine when I installed my Eclipse 8053 //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif And to make it even funnier....I uninstalled a rated 2V deck that had zero alt whine //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif
Preout voltage doesn't affect alternator whine as that's primarily a function of the grounding (voltage potential differences) and not the preout voltage.
And preout voltage is adjustable.....with the volume knob //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif