Anyone else with the Harmon kardon sound system notice distortion. Compared to my old c300 2009 sound system the Harmon kardon really lacks sound quality. It’s funny because my old c300 was basic audio 20 sound system, I would expect the Harmon kardon upgraded sound system to sound better. The bass is very flat also the sound is very raspy. Could this be a blown amplifier? Any help appreciated

 

I have no experience with the HK in the W212 but I did have the system in a 2014 W204 - and I believe they are similar. I had issues with distortion and it ended up being the subwoofer/speaker (one assembly) unit that had to be replaced. Might want to have this checked out.

 

FIXED IT, Found out it was the long speaker vent grille on the rear deck above the subwoofer it was making the sub right below it sound distorted. Crazy what a little trim piece could do to sound quality. Thanks for the help

 

Can you show me any image of this trim piece?
i had an issue when play songs with strong bass,
the subwoofer vibrate the cover above and make noisy like the glass vibrate.. (sixth position on image below)

 

See attachment.

 

Thank you so much but which exactly components i need fix or strengthen to reduce/eliminate the noise when subwoofer thumb/vibrate?