I recently installed an aftermarket Android based navigation/stereo double din in my vehicle. I have a 2002 camry with JBL. I am using this wiring harness from Metra. Everything works well with the exception of a low static that is present on all speakers. When the unit is power off the static goes away so I am positive its coming from the unit.

  • I tried buying 2x ground loop isolators from BestBuy. I put them on the output RCA connectors for the 4 speakers. It seemed to have no effect. When I installed them I connected the brown wire named ground to a black wire named ground on the metra harness.
  • I tried attaching a wire to the double din case and to ground. It didn't work.
  • One thing I did notice is that the navigation/stereo unit has a black called chassis ground. The Metra cable has a black wire called ground and a black/white wire called amp ground. I tried tying them all together but it didn't help.

The sound is fairly low but definitely audible in fact I have been driving with the unit turned off as of late to avoid the sound. People with a touch of tinnitus can't seem to differentiate it. At this point the only solution I can come up with is to wait until I grow old and develop tinnitus myself.

I'm wondering what else I can do to troubleshoot this issue? I was considering going to BestBuy and buying another unit to see if the problem is with the vehicle or the head unit. Another option I wanted to try is to connect the head unit to the physical vehicle chassis but I'm not sure what on the car is consider the chassis.

  • Welcome to Motor Vehicle Maintenance & Repair! May 12, 2019 at 1:52
  • Don't have any personal experience, but if you bought a Chinese Android headunit (typically sporting Rockchip or Intel SoFIA chipsets), then those are notorious for having abysmal analog audio. They'll usually only have outputs of 0.5 V on the RCAs. If yours is a SoFIA unit, you can try looking into getting digital USB audio out, and then using your own USB DAC to hook up to your amp. xda-developers has boatloads of information on this. May 13, 2019 at 15:20
  • Yup pretty much. I bought an Atoto headunit from amazon. It does support USB DAC. Thanks for the info I will look into it.
    – EBCDICman
    May 20, 2019 at 1:07

1 Answer 1


The amplifier might have what I believe is referred to as a floating ground. If memory serves this means that the negative connections on the speakers are not to be connected to the chassis or any power ground. Each speaker has it own discrete +/- connections.

Not all grounds are created equal some are signal grounds while other are power grounds. The ground is like a zero volt reference point. The positive power connection is +12V relative to the ground. The amplifier output would most likely not using the same reference point which could cause damage to your unit.

Connecting the speakers independently should eliminate any possible ground loops.

  • Thanks for taking the time to reply. I understand part of your comment about all grounds not being equal, that some are volt reference points. Can you please explain or provide an example of how to connect the speakers independently. There are 4 RCA jacks on the back of the headunit which I have connected directly to the Metra harness via 4 RCA connectors.
    – EBCDICman
    May 20, 2019 at 1:12

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