In the last 17 years I've owned 6 Pioneer, 1 Eclipse, 1 Denon and 1 Alpine headunits. I've had engine noise on 2 occasions: 1 - I used the factory ground when I didn't know any better yet. 2 - I used the deck power on my first ever deck and didn't have a good ground in my '79 Ford Pinto. //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif
Other than that I've had NO problems with ground noise. Why??? Installation, thats why. I ground ALL my decks in the SAME place I ground everything else in my audio system, in the trunk where I'm sure there is enough good metal for a good ground. No noise for me.
I'm not saying there can't be faulty decks. But a cheap amp, cheap processor such as a in dash eq, trunk eq, trunk x-over or anything powered can introduce noise into a system. In my case it has it is NEVER the deck. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif//content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif