Thread: Alternator noise with PDX-5

I use a grounding point on the right side (passenger) of the trunk on the wheel well, similar to the one on the other side to which the OEM amp was connected; as for the 12v, I use the point next to the battery to which the largest gauge wire is connected.

Quote: Originally Posted by GtiGyver Hi everyone, I'm having major problems with alternator noise following the install of my PDX-5 amp in the trunk. In order to isolate the source of the noise I tried running the amp with nothing connected to its inputs and still had the alternator whine. I also noticed that the whine gets MUCH worse when I drive the car hard. Has anyone solved this issue? How? I have seen a few threads on this issue,...

I currently have two PDX amps installed in my car. The only way I found to eliminate my alternator whine, was to use the factory ground, left side of trunk, fender liner. All other locations incl. battery ground induced noise. It can be very frustrating...

Quote: Originally Posted by GtiGyver I have to admit that I really thought the PDX line of amps would bu much worse for noise from what everyone is saying but TBH when the engine is off, the amps are actually nearly silent. I'll look into maybe the line from the battery having noise from the alternator due to the way BMW uses "Energy Regeneration". I'm getting the impression that the way BMW unloads the alternator...