i am getting a little bit of altenator whine. the gain on my fosgate amp is set about 55%, anymore causes whine. i have checked my ground, ran the fosgate patch cables on the other side of the sc3 than the power wire. if i bought a new headunit (maybe the kenwood mp728), would the 5v pre out help with my whining noise? it already has 1 inline noise filter on it. thanks
WI

 

How many watts RMS is the amp? what size ground wire are you using? Where did you ground it to?

 

its 200x1 @ 4 ohms . the ground wire is 8awg and grounded to a big bolt that goes to the chassis to the left of the gas tank,

 

Use a star washer on the ground connection and scrape off the paint under it to make sure you have a solid connection.
You could also consider adding a line driver to increase line voltage and generate balanced connections to your amp. Try www.audiocontrol.com.