Tips and Modifications to the center speaker for 2019+ Sprinter vans.
=====================================================
The center speaker for the Mercedes MBUX sound system is an enigma. For years, there have been complaints about the Sprinter 2019+ center speaker overpowering the other speakers and having a rather tinny sound. There are small tweeter speakers in the far corners of the dash next to the windshield and larger speakers in each door.
After years of complaints, Mercedes has finally acknowledged their mistake, and it turns out they had the connector wires swapped.
TIP#133: Center Dash Speaker – Many people have just disconnected the black connector from the center speaker and are satisfied with the results.
To correct the wiring, the pins need to be removed from the connectors and swapped. (Instructional in progress)
=====================================================
Speaker Design:
Background: The design of the 2019+ Sprinter center speaker is rather unusual. The speaker is a dual-coil speaker, with one coil is for the Sprinter’s emergency communication system and a secondary coil for the MBUX music system. Disconnecting the emergency coil will display an error on the MBUX system.
=====================================================
Accessing the speaker:
The speaker grill is simple to remove. There are no screws, and a plastic pry tool is used to remove the speaker grill.
.
A pry tool can also be used to remove the speaker. Be careful that you don’t poke the paper cone with your tools.
The speaker is a dual-coil speaker and has two pairs of wires. The emergency contact system is connected to the white connector on the left, while the MBUS music wiring is connected using the black connector.
We will be cutting the white/purple striped wire.
========================================================
FYI: The two speaker coils have different resistances.
The black connector resistance is 6.1 ohms, which would indicate it is an 8 ohm speaker.
.
FYI: The inductance measurements of the two different speaker coils.
The black coil is 25 micro Henrys, and the white is 146 micro Henrys
========================================================
Adding an L-Pad Attenuator:
TIP#140: Center Speaker Volume Control – We added a volume control (L-Pad attenuator) to the center speaker so the level can be adjusted.
An L-Pad attenuator is a rheostat arrangement that controls volume while keeping the amplifier’s output impedance constant. It’s made up of a “L” layout of parallel and series rheostats. The resistance of one increases while the resistance of the other decreases, resulting in a constant impedance.
This L-Pad attenuator is 8 ohms to match the 8 ohms of the speaker and is rated at 50 watts. It was purchased from Amazon $14.99.
The L-Pad attenuator will be mounted in a 3D-printed adapter and inserted into the dash cup holder.
A hole in the bottom of the cup holder is for the wires to feed through and under the dash to the center speaker.
.
The L-Pad attenuator wired and mounted in 3D-printed adapter.
.
L-Pad attenuator installed in the cup holder and connected to the center speaker.
.
The L-Pad attenuator was a nice way to provide an adjustment to the center speaker sound level. While it is a little bigger than I had hoped, it does provide an extra level of volume control if needed when blasting out Led Zeppelin. Once the mix level is set, you probably won’t need to make any other adjustments, so it doesn’t need to be this accessible.