Media system distortion

[Mike Gibb]

I recently bought a Mercedes CLA Shooting Brake Premium Plus. The media system is excellent but from time to time there is audible distortion. It does eventually clear but recurs every few days. It is the same whether I am listening to music or the radio and even the Me Mercedes voice is distorted. Anyone else had this problem and any thoughts how to remedy it?

 

[dry run]

Is it location specific or can it happen anywhere?

 

[Mike Gibb]

Anywhere. First time in Perth, then in Stirling and today in Aberdeen! Not selective. Strange thing is that it clears after about 10 to 15 minutes but I am concerned it gets worse. Guess I will have to take it to the garage but problem is that it will probably be working perfectly when i go.

 

[mioba]

if this happens irrespoective of sound source eg CD, then you can rule out antennae, sounds like a loose connection somewhere

 

[LostKiwi]

Or a failing component in the pre-amplifier or amplifier or if you can narrow it down further speaker perhaps.

 

[Mike Gibb]

Mnay thanks guys. i will get in touch with the garage.

 

[Ron240]

I have a similar model to you albeit the coupe version.
The media system really is excellent as you say, but I have never experienced anything like you describe in my 16 months of ownership.
What I have noticed on rare occasion is a loud single click when talking on the phone...actually loud enough to give me a fright sometimes.
I simply put this down something that happens during mobile communications from time to time and thought no more of it.

 

[Mike Gibb]

Thanks Ron. No this is clear distortion which makes it unlistenable. Fortunately it does clear quickly but I am concerned it gets worse so better to do something about while under warranty.

 

[Ron240]

Yep, absolutely needs looking into.
The only problem with intermittent problems is recreating them when required.
Hopefully your dealer can get to the bottom of it.

 

[Timeandleisure]

Hello, what phone are you using?

 

[Mike Gibb]

Huawei Y7

 

[Timeandleisure]

Since you know the model and year have you checked the information available on MB’s site?

CLA Coupé (02.2019 - ) » Telephone Link | FAQs @ Mercedes-Benz Connectivity

www.mercedes-benz-mobile.com

From what you say you could be experiencing issues in areas of poor network coverage.
I would try using the media system without connecting your phone in the same areas to see if you still experience these issues.

I’m no expert but I recently tried connecting the latest iPhone to the media system in a 67 GLA in an area of low network coverage and the screen was all pixelated and it just didn’t work when plugged using the cable, however I had no issues with an older phone operating system. Hence my question about your phone type.
Probably best to ask at the local MB dealer to rule this aspect out.

 

[Mike Gibb]

Sounds like a real possibility. Thinking about it does sound like interference and the scenario you suggest would explain which it is sporadic. I will try switching off my phone when I am in the car for the next few days and see what happens. Many thanks for your help.

 

[Botus]

I recently bought a Mercedes CLA Shooting Brake Premium Plus. The media system is excellent but from time to time there is audible distortion. It does eventually clear but recurs every few days. It is the same whether I am listening to music or the radio and even the Me Mercedes voice is distorted. Anyone else had this problem and any thoughts how to remedy it?

usual causes...
1) interference - unlikely as you say its happening with a music source as well (or are you saying radio only on music or speech?)
2) reception issues - likely, DAB is terrible, some areas running on almost zero signal, (later ones can try to flip flop between FM to DAB hoping something works)
3) vol of the scale - clipping and other speaker driver abuse trying to get it too loud, these days systems have in built way to wind back (not so common as it was)
4) driver damage - usually from idiots that push bass to the max and listen to utter drivel and blow the speakers till they rattle and screech, then give up
5) factory sub clipping - mate with his A8 & 6k option hifi used to get this. It didn't protect itself, he had wound near max bass, needed100w more grunt to run right
6) nasty software - many will think this implausible, but don't take anything for granted on modern cars - insist dealer check for TIPS docs and or updates the car

 

[Mike Gibb]

Thanks for all those suggestions. Happens on Bluetooth, USB, radio and Mercedes voice. Volume is kept at modest level and bass at mid point. Car was only 10 months old when I bought it so probably unlikely that any previous owner could have damaged the speakers. Anyway once it clears speakers sound perfect. All very strange.

 

[Botus]

Thanks for all those suggestions. Happens on Bluetooth, USB, radio and Mercedes voice. Volume is kept at modest level and bass at mid point. Car was only 10 months old when I bought it so probably unlikely that any previous owner could have damaged the speakers. Anyway once it clears speakers sound perfect. All very strange.

If its happening on non OTA (over the air signals) like a good music file on USB, it sounds like hardware / wiring issue as its impacting other sources as well

How old is the car inside its original warranty ? ... if so when you book it in ask (if its a comand system) for the latest Maps to be loaded... should be a freebie inside the first 3 years but you have to encourage them... might as well try and get something for the agro of dropping it in.

 

[Mike Gibb]

It is a 70 plate, first registered in October 2020, so I will ask them to do that. Thanks for your help and suggestions.