AUX static noise
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Joined: Feb 2022
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W212 Facelift
AUX static noise
Hi I am having issues with static noise on aux. Whenever I just start ignition it has static when I start engine noise gets worse and when I rev its worst. I just noticed this as I installed roadtop kit which uses audio with ami cable, was using bt before. What should I look for to diagnose this?
P.S without ami cable noise is still there but less loud.
P.S without ami cable noise is still there but less loud.
Last edited by Navrozashvele; Mar 18, 2022 at 09:41 AM.
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Joined: Apr 2019
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From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
Noisy electricals bad with Roadtop...
Hi I am having issues with static noise on aux.
Whenever I just start ignition it has static when I start engine noise gets worse and when I rev its worst. I just noticed this as I installed roadtop kit which uses audio with ami cable, was using bt before. What should I look for to diagnose this?
P.S without ami cable noise is still there but less loud.
Whenever I just start ignition it has static when I start engine noise gets worse and when I rev its worst. I just noticed this as I installed roadtop kit which uses audio with ami cable, was using bt before. What should I look for to diagnose this?
P.S without ami cable noise is still there but less loud.
These modern cars are loaded with strong noise sources (injectors, Ignition coils, FuelPump, Engine Fan, Alternator,...).
Try to use grounded shielded coaxial cabling for signals and capacitors to cleanup the power supply of your roadtop audio unit.
Also experiment taping power at different locations hopefully less noisy.
Try to figure if your electric noise gets in the power or the audio then concentrate on that.
Thread Starter
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W212 Facelift
Third party device introduces audio noise.
These modern cars are loaded with strong noise sources (injectors, Ignition coils, FuelPump, Engine Fan, Alternator,...).
Try to use grounded shielded coaxial cabling for signals and capacitors to cleanup the power supply of your roadtop audio unit.
Also experiment taping power at different locations hopefully less noisy.
Try to figure if your electric noise gets in the power or the audio then concentrate on that.
These modern cars are loaded with strong noise sources (injectors, Ignition coils, FuelPump, Engine Fan, Alternator,...).
Try to use grounded shielded coaxial cabling for signals and capacitors to cleanup the power supply of your roadtop audio unit.
Also experiment taping power at different locations hopefully less noisy.
Try to figure if your electric noise gets in the power or the audio then concentrate on that.
Out Of Control!!
Joined: Apr 2019
Posts: 11,923
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From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
minimizing noise issue...
There is static without roadtop unit. When AMI cable unplugged, static is there just barely noticeable on low volume, on high it's really noticeable but once you plug in AMI it is way louder(roadtop amplifies sound, it's a setting, if you turn it down, static gets less noisy). Ami cable has 3 legs so I think it's audio part to map just AUX so I believe it's audio issue.
You're saying that's where the noise is being picked up. The input is always noisy ... correct?
> S'nR: signal noise ratio:
Can you set a higher audio level into this input ?
This way you don't use a higher volume setting to amplify (low audio + high noise).
You want (high audio + low noise)
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W212 Facelift
Do you have a picture of this AMI 3 legged cable?
You're saying that's where the noise is being picked up. The input is always noisy ... correct?
> S'nR: signal noise ratio:
Can you set a higher audio level into this input ?
This way you don't use a higher volume setting to amplify (low audio + high noise).
You want (high audio + low noise)
You're saying that's where the noise is being picked up. The input is always noisy ... correct?
> S'nR: signal noise ratio:
Can you set a higher audio level into this input ?
This way you don't use a higher volume setting to amplify (low audio + high noise).
You want (high audio + low noise)
About 2nd part. aux comes from roadtop unit which is feeding audio with setting amplifies audio to max(my current setting) to ami so I believe it will cause high audio with lower noise compared to if I dial down setting so I am doing it properly I assume. On the other note on max volume I can't stand static but if you turn on music you cant even hear static lol so like I can technically let it slide but I am perfectionist and will get at root of this issue 100%
By the way. Once you have time, can you please try switching to aux at max volume to see if you hear static too? you have '14 car so you should have NTG 4.7 unit too.
I believe my whole interrior is rebuilt and someone f'd up wiring I am almost certain
Last edited by Navrozashvele; Mar 18, 2022 at 02:40 PM.
Out Of Control!!
Joined: Apr 2019
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From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
testing Aux input
"Try switching to aux at max volume to see if you hear static too?"
How can you switch over to the Aux input???
There is an interface module in some of these cars, perhaps it's what introduces noise picked through unfiltered dirty 12v... or wire harness coupling travelling side-by-side ?
How can you switch over to the Aux input???
There is an interface module in some of these cars, perhaps it's what introduces noise picked through unfiltered dirty 12v... or wire harness coupling travelling side-by-side ?
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Thread Starter
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W212 Facelift
"Try switching to aux at max volume to see if you hear static too?"
How can you switch over to the Aux input???
There is an interface module in some of these cars, perhaps it's what introduces noise picked through unfiltered dirty 12v... or wire harness coupling travelling side-by-side ?
How can you switch over to the Aux input???
There is an interface module in some of these cars, perhaps it's what introduces noise picked through unfiltered dirty 12v... or wire harness coupling travelling side-by-side ?
in my case that big square port is adapter to female 3.5mm so that I can plug in roadtop box output
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Joined: Nov 2017
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From: Arizona
2014 E550
What type of device are you plugging into AUX?, some GSM radios in phones can cause additional electrical whine when antenna is activated.
Have you tried replacing the MB aux adapter cable? Mine had a kink and caused noise
Have you tried replacing the MB aux adapter cable? Mine had a kink and caused noise
Thread Starter
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W212 Facelift
So from my observation whole car interrior is rebuild badly. Static noise somehow is really familiar how the fan of head unit sounds. I this is bad wiring -> bad ground. Everything hints to 3.5mm ground loop isolator or as they call it "filter" in my country. I will have it made and update with results.
Thread Starter
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W212 Facelift
It's short cable without kink. Static is there without plugging in anything so it's internal bad wiring caused by probably rebuilding interrior. I am plugging in roadtop carplay kit input.
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W212 Facelift
If it works, it works, if it doesn't I dont really care much. I am going to be selling my car anyway and looking to buy E400 either sedan or coupe. Not worth repairing it from my end. Will probably pull this kit during sale so I can put it in next car.
