I installed my MKII into my 2001 Miata using an MTX 4 channel amp. I also installed a JL Audio 8 inch sub under the passenger side wheel well and infinity separates in the doors. All is fine except that I have this alternator whine that drives me crazy when listening to soft passages or to a talk radio station. I am sure there is a ground loop somewhere, but the installer did ground both the amp and the HU to one grouding point in the trunk. I also have the radio module, BTW, and a power antenna. Finally, the whine gets worse when i turn on the A/C!

any and all help will be appreciated!