I have been having an issue with my amp/subs with an odd and loud kind of hum. It does not matter what I am doing, it just comes and goes and the volume of the hum has nothing to due with the stereo volume. Anyone have any ideas of how to correct it? The amp is MTX and the subs are JL in a stealth box. Head unit is an Alpine. The truck is a '99 XLT extra cab.

 

Turn down the gain on your amp juts till the hum goes away should be good after that

 

You probably have ground loop interference. There is a device called a ground loop isolator that works well. Or maybe try heavy shielded audio cables. I had a similar problem.

 

This!

 

+1 on that. Ground loop isolators come in RCA in-RCA out to go between head unit and amp. Most Radio Shacks carry them, or else, Ebay (they're all made in China now).