HK Center speaker 2014 W212
did you have that issue and just upgraded to a better speaker??
I have a year of CPO warranty remaining and it states the stereo / radio is covered so will see what the dealer says.
Guess what, the system still sounds great, so I'm just running without that center channel.




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If you have any instructions on how to take it apart or any possible ideas why the speaker is popping/cracking it is much appreciated!
Here is the link to my video of the speaker cracking.




If you have any instructions on how to take it apart or any possible ideas why the speaker is popping/cracking it is much appreciated!
Here is the link to my video of the speaker cracking. https://www.youtube.com/watch?v=958VkYZJ-KY
PULL YOUR AMP FUSE or harness plug ASAP to save you $$$$
I have seen up close how the main Amplifier module is built with amazin' capacitors rated at 16Volts max...
Once all the caps start leaking DC voltage through, the days of your speaker set are numbered.
To save your speakers... fix the amp!
I have not yet seen the woofer amp module... soon, on my way to dealing with my roll-up blind unit.
How many of you are interested in fixing their OEM amp (caps and heatsinks) under $10?
Last edited by CaliBenzDriver; Sep 20, 2021 at 05:01 PM. Reason: interest in preventive fix
PULL YOUR AMP FUSE or harness plug ASAP to save you $$$$
I have seen up close how the main Amplifier module is built with amazin' capacitors rated at 16Volts max...
Once all the caps start leaking DC voltage through, the days of your speaker set are numbered.
To save your speakers... fix the amp!
I have not yet seen the woofer amp module... soon, on my way to dealing with my roll-up blind unit.
How many of you are interested in fixing their OEM amp (caps and heatsinks) under $10?





Do you know where the fuse is that i can pull it out till i get it checked out? BTW, i thought there is only one amp in the car? I thought i disconnected the one to the speaker? Do you know if it is the head-unit? Is there an amp there i need to worry about as well?
Pulling multiple shared fuses will power down additional systems you may still use. Simply pulling plug is a better choice to stop frying your set of speakers.
To answer your question, I do not think the head unit has any power Amps built in. There are nearly coutless different types of COMAND units for the E cars so yours may be a different gem than mine.
pull these 2 plugs OUT, carefully.
Last edited by CaliBenzDriver; Sep 21, 2021 at 06:00 PM.
Pulling multiple shared fuses will power down additional systems you may still use. Simply pulling plug is a better choice to stop frying your set of speakers.
To answer your question, I do not think the head unit has any power Amps built in. There are nearly coutless different types of COMAND units for the E cars so yours may be a different gem than mine.
pull these 2 plugs OUT, carefully.




Replacing a hand full of caps is the quickest and cheapest way to save your OEM unit with limited output power.
I think piggybacking an aftermarket Amp is the best long term fix to gain serious RMS power. I don't think you can bypass the DSP but I could be wrong.
In either direction, the first step is to start by fixing existing unit ...




getting an aftermarket amp working is tricky, as the connection from the COMAND to the main amp is a digital fiber optic databus ("MOST")
Replacing a hand full of caps is the quickest and cheapest way to save your OEM unit with limited output power.
I think piggybacking an aftermarket Amp is the best long term fix to gain serious RMS power. I don't think you can bypass the DSP but I could be wrong.
In either direction, the first step is to start by fixing existing unit ...

Thanks!




- front left door woofer
- front left door midrange
- front left mirror triangle tweeter
- front right door woofer
- front right door midrange
- front right mirror triangle tweeter
- front center channel
- rear left door woofer
- rear left door tweeter
- rear right door woofer
- rear right door tweeter
- rear left pillar surround/tweeter
- rear right pillar surround/tweeter
- rear trunk area subwoofer
the B&O premium system has the same setup as the HK Logic7 system, but different speaker and amplifier part numbers




The main Amp is located in the trunk left side. Once you get it open, a collection of 16V caps will be your target for replacement with higher voltage and about similar capacitance. They are used to filter out the output DC voltage from reaching the speaker coils. The limiting factor here is the available room for cap size! I did run a part search a while ago... will add edits about findings.
@Left Coast Geek shows us the way the Amp outputs are individually served with pre-filters. This is a luxurious solution.
Traditional "LC-filters" are only great on paper, in practice they waste a lot of power. Here our frequency cut-off filtering is nicely done ahead of amplification. This way the two front doors use no less than 6 amplification channels, great !
"Recycling" free channels:
I recall the amp chips showing proprietary markings (unknown replacement) - If you have a bad chip for your center spk use one of your rear door channel!!!
Rear doors use 4 channels... you rewire the tweeter to a serial 2uF cap, hooked up in parallel to woofer - This single cap is the highly efficient filtering used in my Bose speakers.
Having freed two channels (L+R Rear tweeters) you can move the chip to replace your center channel if bad beyond a leaky 16V cap.
Plan B...Simplify!
Okay, you say life is short, let's just loose the front center channel.
This is the easiest way >😊
In this case you renew all your 16Volt caps and if the center chip is bad, you let it be. At least frying other speaker coil will be prevented.
Oz of prevention:
> You want to upgrade the liquidy OEM thermal paste that's running down the vertical heatsink... ouch! Use good silver CPU paste for a superior grade.
> Furthermore you put on your eye glasses and realize the heatsink mating surfaces are rough unmachined AL casting...
polish them a bit with your Dremel tool.Now your main Amp will perform reliably well.

+++ Edits+++++
double check this Capacitor Ref# UPW1E472MHD
4700uF 25V 105°C 18x35x8 radial
$1.49Ea. at Jameco, Digikey or Mouser
✌️
Last edited by CaliBenzDriver; May 18, 2022 at 05:14 PM.




center channel is H4/27 here.
https://mbworld.org/forums/attachmen...ram-logic7.pdf
N123/4 or N112/2 there is the 'telematics services' or Emergency Call System box.
So I would leave the center channel speaker physically in place, and just disconnect he "S" jack (grey, brown/grey) and not the "LCT" plug (brown/green and green)
on my old W124 wagon, the right speaker had dual voice coils, one for the cellular phone, the other for the stereo.
The main Amp is located in the trunk left side. Once you get it open, a collection of 16V caps will be your target for replacement with higher voltage and about similar capacitance. They are used to filter out the output DC voltage from reaching the speaker coils. The limiting factor here is the available room for cap size! I did run a part search a while ago... will add edits about findings.
@Left Coast Geek shows us the way the Amp outputs are individually served with pre-filters. This is a luxurious solution.
Traditional "LC-filters" are only great on paper, in practice they waste a lot of power. Here our frequency cut-off filtering is nicely done ahead of amplification. This way the two front doors use no less than 6 amplification channels, great !
"Recycling" free channels:
I recall the amp chips showing proprietary markings (unknown replacement) - If you have a bad chip for your center spk use one of your rear door channel!!!
Rear doors use 4 channels... you rewire the tweeter to a serial 2uF cap, hooked up in parallel to woofer - This single cap is the highly efficient filtering used in my Bose speakers.
Having freed two channels (L+R Rear tweeters) you can move the chip to replace your center channel if bad beyond a leaky 16V cap.
Plan B...Simplify!
Okay, you say life is short, let's just loose the front center channel.
This is the easiest way >😊
In this case you renew all your 16Volt caps and if the center chip is bad, you let it be. At least frying other speaker coil will be prevented.
Oz of prevention:
> You want to upgrade the liquidy OEM thermal paste that's running down the vertical heatsink... ouch! Use good silver CPU paste for a superior grade.
> Furthermore you put on your eye glasses and realize the heatsink mating surfaces are rough unmachined AL casting...
polish them a bit with your Dremel tool.Now your main Amp will perform reliably well.

+++ Edits+++++
double check this Capacitor Ref# UPW1E472MHD
4700uF 25V 105°C 18x35x8 radial
$1.49Ea. at Jameco, Digikey or Mouser
✌️



