It seems that whenever my wife uses her E350's Bluetooth to talk on the phone, the sound quality is seriously terrible. I always end up asking her to "pick up the phone" vs. using the car's Bluetooth. Has anyone else had a similar issue? In our BMW, Infiniti (excellent), Porsche and even my lowly VW winter car, the Bluetooth phone quality has been acceptable. Does the E350 have any "noise cancellation" feature at all? Maybe this is the issue? Is there a "hidden configuration" that I can set to fix this?

No problem with a 2011 E550. Using an iPhone 5S and a Samsung Galaxy III S

Maybe find where the microphone is in your car and make sure nothing is hanging in the way?

I used a 5 and my wife a 4s and they are fine over BT in my 2011 E350.
See if you can get a friend with a different phone, pair it and then test it. It could be the phone. If the problem persists perhaps a dealer can sort it. Could be software I guess but who knows.

I will have to try a different phone. The "loudness" is fine. But the "quality"
of the sound on the other end royally sucks...


So no one on the other end of the conversation ever complains on you guys?

I get the same complaints on my 2012 E w/Iphone 5 - too much ambient noise at hwy speeds.

I've tried up'ing and lowering the mic volume, but no love. I haven't tried another phone.

Now that is interesting. If it is OK at around town speeds why the difference.
My old Samsung 320 phone was just a phone with BT connectivity and it worked fine in my 2009 W211 and in the current W212.
I would be interested to know how that works out.

How did you increase or decrease the mic volume?

I am not able to find anything in my manuals re adjusting the microphone in my 2011 but I am wondering about this.
If you go into System>Settings>Voice Control is Individualization checked?
Did you try Start New Individualization?
I did mine when I got the car and while they say that it may interfere with the system's ability to recognize others, it sees my wife and my grand daughter as well as it recognizes me.
My reference is page 42 Voice Control System Settings in the Comand Supplement Manual for the 2011 model year. More recent systems may be different controls but perhaps there is something similar in newer models

I don't know what phone the OP has but when there is a problem with phone compatibility, it might be good to check the phone compatibility charts on the MB web site (owner's section). My phone (Droid RAZR MAXX HD) was on a previous list but was dropped off for 2014+ for some problem with connection. I notice mine reconnecting the phone occasionally while driving, after it was already connected. I also cannot receive text messages for some reason, even though the pairing would indicate otherwise. There are all kinds of incompatibilities related to 'Comand' revision, type of phone, Android s/w and phone s/w revisions, etc.

With regard to changing speaker and mic volume, I think it's like the Nav, where you must make the change during use, but I'm not sure if it controls one or the other or both.

Well, I guess that doesn't really help solve the problem.

The Voice Individualization only has to do with the car learning how YOU say things with regards to voice command. My issue is having the person that you are speaking with through the car Bluetooth not understanding me since the voice quality sucks.


I called someone from the car today and there was no MIC volume control. It was only ON/OFF. I have a Nokia phone and it is compatible so it seems that the quality of the phone transmission signal to the other party sucks.

Sorry then nothing much to ad. No magic it seems. I was just speculating that perhaps the system would re-learn in a way that would clear up the voice transmission. At this point I felt it might be worth a try but what ever.
Perhaps the mic in your car is bad.
Suggest a visit to someone with intimate knowledge of the system as many of us trying to help out do not have the problem as you no doubt can see.

No issue in my 2010 with iPhone. Something must be wacky with the setup. Does your NAVI screen always show a strong signal from the phone? I'm talking tower signal, you know full bars?

OP: Did you buy the car pre-owned? Any warranty remaining? I'd ask dealer service to check it out. Maybe see if you can demonstrate the problem by calling the SA or Tech right there.