JHS666

Hi,
Ive a 2015 E220 with the Harmon/Kardon Logic 7 sound system. The problem I have is theres a distortion coming from the rear speakers / subwoofer. It happens in many various songs with bass, the songs are all good quality etc. The noise im hearing is a distortion in the speakers or subwooder, its not like the song is being played too loud etc., and the sound adjustments are all in place. I suspect its the subwoofer but cant be sure. I have removed the the black cover thats on the rear shelf that covers the subwoofer and the noise can still be heard, theres nothing obviously loose there or in the boot either from underneath. i have carried out a diagnostics on the sound system and theres no faults. Im going to book it into Mercedes and see what they say, but just wondering before I do has anyone else come across this problem in there W212 with the harmon kardon system?

Thanks

belarus27

Im not sure if 2010 and 2015 HK logic 7 is the same , but ive got this probably a year after i bought the car(atleast i noticed that in a year lol)
There are threads on this forum , and from what i remember reading is that your subwoofer speaker is burnt (the coil in it). Too much bass , or music too loud.. idk what could be a real reason to this.

maybe there are different ways to fix this , but easiest one is probably to replace the sub.

mj_39

Max_1

I had a similar issue. In my case, I could hear some "rattle" from the rear shelf when music was bass loaded.
I could make "rattle" stop by pressing on the shelf and the grill.
Since it is still under warranty, I found a specific song on my SD card that would cause this to appear and took it to local MB dealer. It did take two attempts. On the first one they claim usual "can not replicate the problem". On the second attempt I got shop foreman to confirm the issue and than fix it. Based on the feedback that I got, the shelf was removed and some foam/padding was glued to it to quiet it down.

Max

mj_39

nc211

Max_1

Found one more reference where the sub speaker itself got damaged:

https://www.benzworld.org/forums/w22...epair-fyi.html

This reference is for the S-class but I think the one used in E-class is nearly identical.
Max

mj_39

mj_39

JHS666

I took my car to the dealer. They carried out diagnostics and there was no fault codes which i knew already as i had checked it. They took up the rear parcel shelf and checked was everything tight etc. They heard the distortion however they told me that they checked another car they had with the Harmon Kardon sound system and that it made the same distortion noise and could not replace the sub-woofer as its a fault with them sound systems. I heard the distortion in the other vehicle thet had which was a C class W204. End result was they told me to remove to the rear pacel shelf and install some sound deadening.

mj_39

konigstiger

fwillie123

2016 Eclass Cabriolet, Harmon Kardon speaker distortion, mine is strange:
1. When top is up, system is booming. Can't make it distort.
2. If top is lowered while system is turned up, will continue to blast perfectly (speakers must be OK).
3. If ignition turned off for 10-15 min (with top down), when started up,distortion is obvious.
4. Only solution is to raise top for a few seconds and lower it again. Not good for wear and tear on top systems.
5. When top finishes operation cycle and makes final latching(locks into place), system sound booms again.

Will take to MB ASAP.

fwillie123

Follow up to distortion. Took to MB. Shop says no code stored. I am convinced that code storing more often than not, not a good indicator of most bad sounds. Had to get shop tech to sit in car with me. Used fader to move sound to center, and front dash tweeter was scratchy and sounding horrible. Tech agreed that tweeter was bad. Found an article that said sun shining through windshield will cause them to go bad. Part on order, will give follow once installed.

TeeEl

That's a friggin' bummer. Get yourself a sunshade speficially made for the W212 windshield.

qmciver

I just purchased a W212 with HK logic 7 and it also had a distorted sound coming from the rear. My buddy was riding with me and heard the noise and immediately went into my settings under Bluetooth audio and turned off the “boost” mode. The sound changed to what I would expect from the system immediately.

jonUF02

The stock "subwoofer" if you can even call it that is horrible garbage. I disconnected it when I installed a proper subwoofer in the trunk. The rest of the system actually sounds pretty good. I balanced the new sub level with the rest of the system, I'm happy with the outcome for years now. I've had a lot of extensive stereo installs in the past, and this keeps me happy.

https://mbworld.org/forums/e-class-w...r-install.html

TeeEl

Yup. I had to do the same thing and have mentioned it on numerous threads as well.

jonUF02

Also, for music I turn off the fake surround "Logic 7", it's only good for maybe talk radio or movies