Saturday, January 28, 2023

Replacing/ Upgrading Sprinter Door Speakers, and Dash Tweeters. Installing Sound Deadener on Cab Floor

Our factory door speakers broke, the rubber surround that holds the paper cone has disintegrated into pieces, causing the speakers to sound terrible. I used an eBay speaker adapter to replace it with a larger speaker. The factory speaker is proprietary and cannot be simply replaced with an aftermarket speaker without the use of an adapter or some modifications.

The new speakers have a much better dynamic range and a deeper bass response. I also replaced the tiny dash tweeters and was very pleased with the upgraded speakers. Here's how to change them.

Tool's you'll need:

Supplies you'll need:
Step-by-step procedures:
Disconnect the chassis ground connection. Sprinter ground disconnect is located next to the gas accelerator (as pictured). Per MB recommendation, wait approx. 10-minutes after engine shut down before disconnecting ground.

Remove the door panel. The two upper T-20 bolts are covered with plastic cap as pictured above.

I use a hot glue stick to remove the caps, melt the end of hot glue stick with a lighter, stick it to the screw cap and hold it for few seconds until glue solidifies then immediately yank it out, the cap should cleanly pop out. You can also use a thin tool to pry the cap out, but it might leave some marks on the soft plastic.

Remove the two lower T-20 bolts behind the lower storage bin.

Use a trim removal tool to pry off the door handle plastic surround. Note the location of the locking tabs in the picture.

Remove the two T-30 handle bolts.

Pry the lock surround out with a small trim removal tool... or grab the surround with your finger by pulling the panel away from the frame, then simply pull the surround out.

Starting from the top right corner, pry out the plastic door panel from the metal door frame. Once you popped some clips out and able to grab the inside of the door panel with your fingers, start pulling the panel away and you should be able to pop the green clips one by one. The bottom of the panel hooks into the metal frame, you can leave it hook for now till you unplug the window control wirings and the lock cable.

Unplug the wire from the window control switch in the plastic panel. Using a flat head screwdriver, carefully slide out the door lock cable connector (yellow barrel shaped plastic piece) out of its holder. Unclip the smaller yellow piece from the L-shaped cable end, do not remove the small yellow piece from the panel. 

The plastic door panel can be unhooked from the metal frame at this point. Unplug the door speaker wiring. Note my disintegrating door speakers.

Remove the four screws around the speaker then use same screws to mount the speaker adapter in place. The speaker hole has the white plasticky material molded into it, I have to slightly trim it out to fit the new speakers. 

The white plastic cover on the passenger door was already partially unglued from the metal frame, I was surprised that the door has factory foam sound deadener installed, one less work for me.

I first made a paper template of the back of the door panel then transferred it to the 3M Thinsulate insulation. The 3-linear feet of Thinsulate is enough to cover both front doors, do not put insulation on the inside door cavity where the door window parks. I use 3M Hi-Strength Spray Adhesive 90 to glue the 3M Thinsulate into the back of the panel. 

Prepping the speakers: I have to fold back the speaker wire terminals to clear and fit the speaker into the speaker hole.

Prepping the speakers: The speaker wire terminals are then covered with heat shrink tubing and electrical tape to prevent possible shorting with the metal door.

Run the speaker wire inside the door and out where the factory wire bundles exit next to the window control switches. Mount the speaker in place, carefully pre-drill holes in the spacer and attach the speaker screws. 
I use smaller #8 1/2" long screws to mount the speaker in place. The 6.75" speaker is slightly larger than the speaker adapter and the speaker holes is almost at the edge of the adapter ring hence the use of smaller diameter screws.

Cut the original speaker wire plastic terminal and use butt crimps to connect it to the new speaker wires. Driver side door wiring (Brown/Purple is +); Passenger side door wiring (Brown/Orange is +).

I use felt cloth electrical tape to bundle the speaker wires to the window control switches wires.
Replace the plastic door panel. First, check the speaker if it clears the plastic edge of the door panel speaker opening before fully attaching it, otherwise you might have to trim the plastic for proper fitment. My speakers did fit perfectly with no trimming needed. Before closing everything back up, it's a good idea to test the speakers first if it works.

Optional: Replacing the Dash Tweeters 
The factory dash tweeters are tiny and barely makes any sound. Although the replacement tweeters are same 1" size as the factory ones, the actual replacement tweeters are actually bigger. The factory tweeters are smaller with a bigger diameter casing.

Using a thin tool or a small flathead screwdriver, pry off and remove the tweeter grille. Remove the A-pillar to expose the second T25 Torx screw that holds the tweeter surround in place.

Undo the first T20 Torx screw next to the tweeter. I use a Flexible Extension Drill Bit Holder to remove the Torx screw, due to proximity to the windshield there is not enough space to fit a regular Torx driver. A short or stubby driver should be also okay. 

The second T-25 Torx screw is behind the A-pillar.

Once the two T-20 screws were removed, slightly push the tweeter surround forward (to unclip if from dash- pointed by 2 short arrows in the picture above) then slightly pull it up just enough to fit your hand below the tweeter location. 

Pop out the tweeter from the base of the surround. It’s held in place by two plastic clips. 

A comparison between the replacement tweeter (left) and the factory tweeter. The factory tweeter is actually smaller with a bigger casing.

The replacement tweeter comes with a flush mount plastic adapter which is not needed.

The tweeter wires were cut short to about 6 inches long then butt spliced into the existing tweeter wiring using crip-on butt connectors. 
*Driver side door wiring (Brown/Purple is +); Passenger side door wiring (Brown/Orange is +).

Push the tweeter into the underside of the surround, it should clip in place. The replacement tweeter plastic body is thicker than the factory tweeters preventing the surround clips to fully seat into the tweeter body, but it still holds it in place. The replacement tweeters are much better sounding than the factory tweeters. Highs and lows are played very well with the upgraded tweeters and door speakers, it got enough bass that a sub might not be needed. Pretty happy with the upgrades! 

Optional: Sound Deadener Installation to Front Cab Flooring
You need 18 square feet of sound deadener to cover the front cab flooring.

You need to remove the factory rubber and foam mat that covers the floor. Thoroughly clean the floor using degreaser or isopropyl alcohol.

I started laying the sound deadener from the rear to the front of the cab. To minimize waste, I first made a paper template of the floor and working my way towards the front one section at a time.

I use a mat roller to flatten the sound deadener into the floor for a good bond.

The battery metal cover with sound deadener installed. Once done, replace the factory rubber/ foam mat and give yourself a pat in the back.


  1. Great writeup. How do you rate the addition of sound deadener?

    1. Thank you. It reduced road noise slightly, but not substantially. The road/wind noise is transmitted throughout the cab in all directions, via the windshield, doors, windows, floor, and so on, so I wasn't expecting a significant noise reduction. I'll have to see how it performs with the under chassis radiant heat rejection when summer arrives.

  2. I’m getting ready to install tweeters in my Roadtrek. The tweeters I bought have in-line crossovers. I noticed yours didn’t. Are there crossovers already in the Sprinters tweeter wires?

  3. The factory and replacement tweeters have built-in small capacitor filter, it's directly soldered into the + post of the speakers, nothing on tbe wirings.

    1. I guess I’ll be returning my tweeters. I could probably squeeze the crossovers in, but the ones you used are a cleaner fit.


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