SGZC12RC External Microphone DIY mod

Split from the power and ground wires from behind the radio.
 
Split from the power and ground wires from behind the radio.

suggest wiring the ground to a chassis ground point and not the ground wire off your radio, radios typically can have 3 grounds, radio chassis ground, speaker ground and antenna ground and it's easy to get a ground loop when wiring to your radio
 
Ok, will try to see if there are any good places I can mount to the frame itself or the frame tubing (there's some visible behind the radio). This will likely take some time though.
 
the frame tubing is not always good either, the framework behind the dashboard is often on insulated mounts to minimise vibration

find the fuse box and there should be a proper ground point nearby

will look something like this

ground point.jpg
 
Will surely check with the multimeter, if the tubing is grounded or not.
If not, guess I'll have to find a place to connect to the frame itself somewhere. The fusebox is on the other side of the car, so it's a bit inconvenient.
By the tube I mean a thick 2-inch pipe, which runs from one side of the car to the other for structural and safety support for the frame of the car.

I get why you recommend the frame instead of wires though from understanding the electron flow (battery negative terminal -> frame -> camera).
 
Ok, will try to see if there are any good places I can mount to the frame itself or the frame tubing (there's some visible behind the radio). This will likely take some time though.
even the tube that's bolted to the frame and you bolt tot he tube can have a bad earth. I always take from the frame itself or an existing earth point or I make one in the metal frame, never from something that is bolted onto the frame, very hard to trace a bad earth from that.
 
Well, it doesn't seem to be a grounding issue after all.
I remember I moved the microphone cable around (well, it's still routed the same way, just pushed it slightly when adding some tape around the microphone, because it had came loose in its mount) slightly and now the noise is gone again.
I guess it must've been just from being close to some power wires behind the radio, where I've routed the microphone from.

By saing that "I remember" I mean that I did that on Friday and I only now checked the recordings after a small trip.
 
Still having those audio noise issues.

What's weird is that physical location etc in the car doesn't seem to matter much, the noise comes and goes as it pleases.
Didn't touch the main unit, microphone etc, but even when everything is shut off (car locked, key is out), so the only things running are the standby stuff in the car (alarm, car lock remote system etc) and the camera, the noise is still there sometimes.
Sample of "offline" noise:
Code:
https://youtu.be/yLriRNGwKDQ?t=2m13s
Sample of clean sound:
Code:
https://youtu.be/1_lSLk8cMAU?t=2m
Here's when the noise stards during a drive, comes in gradually:
Code:
https://youtu.be/azQy_qM_qkM?t=1m30s

Main thing is: the unit and microphone have stayed stationary inside the car (exactly the same location).
 
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Since this camera comes with just a straight wire from the cigarette lighter connector to the camera board, I'm thinking of switching the cable out completely and integrate a proper LC filter into there to combat the noise.
Could you (Jokiin?) tell me what the spec of the connector is?

If not, I guess I can just cut the connector off and use the existing one.
 
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