Taming the Center Speaker

GLJones

Active member
I have the 10" MBUX system on my 2019 2500 170 Passenger Sprinter. The center speaker is too loud and there is no way to control it. The fader controls do not affect it at all, only the door and rear speakers. Many on this forum have disconnected it making the overall sound better.

I decided to control it. I popped the cover off the center speaker and disconnected one of two connectors attached to the speaker. Just pull the speaker straight up and it will pop out, then disconnect the connector closest to the windshield. DON'T disconnect the other connector or your SOS system and other non-music signals will stop functioning.

I then took the connector and cut the purple wire. I ran 2-conductor wire from the speaker housing straight down into the dash to toward the stearing wheel. Under the dash, I pulled it down to the switch plate to the right of the steering wheel. I popped off one of the blanks and ran the wire through the opening.

Then, I soldered the 2-conductor wire to each end of the purple speaker wire I had cut, then used shrink-tube to insulate the connection. I reconnected it to the speaker, replaced the speaker and the speaker cover.

Then, I modified the switch blank I had removed from the dash. I removed the plastic ribs inside the back of the switch plate and cut the sides down to fit a small 5K potentiometer. Once it fit, I marked and drilled the hole through the front for the control post to fit.

Then, I connected the 2-conductor wires to the potentiometer. Connect to the center post and one of the side post. Select the side post based on which one makes the control work left-quiet to right loud. If you pick the wrong post, the control will be backwards. I soldered the connections.

Then I slid the potentiometer into the switch blank and secured it with the nut. Then, place the control knob on it and everything is done.

Now, I can control the volume of the center speaker to my liking. For music, I turn it off. For talk-radio, the center speaker improves legibility in some frequencies.

The entire project only took about an hour. The hardest part was modyfying the switch blank.

I included some photos. I didn't remember to take any of the center speaker. Photos are the switch area and a video you can sort-of hear the difference through my cell-phone microphone.

Video of results: https://www.youtube.com/watch?v=mMGxX5vaWIw

Parts
5K small potentiometer
control knob
2-conductor wire (3 feet)

Tools
plastic pry tool (to remove speaker cover)
wire cutters/stripper
soldering iron
shrink tube
exacto-knife
drill
 

Attachments

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Dave-Oh

New member
I have the 10" MBUX system on my 2019 2500 170 Passenger Sprinter. The center speaker is too loud and there is no way to control it. The fader controls do not affect it at all, only the door and rear speakers. Many on this forum have disconnected it making the overall sound better.

I decided to control it. I popped the cover off the center speaker and disconnected one of two connectors attached to the speaker. Just pull the speaker straight up and it will pop out, then disconnect the connector closest to the windshield. DON'T disconnect the other connector or your SOS system and other non-music signals will stop functioning.....
GREAT IDEA! I disconnected the center speaker which MUCH improved the system, but your solution looks simple and for speech would be a nice boost. I may get ambitious and give it a whirl! Thanx for the great idea and for posting the materials and results!

best,

Dave
 

GLJones

Active member
Or even a simple switch. Switch on for talk, switch off for music.
That was my backup solution if the volume control didn't work.

I took a drive to Lowe's today and experimented with the volume. I found a nice median where the center speaker sounds good but doesn;t override the rest of the system. It sounds quite good, for a stock system. I think I like having the center speaker but turned down to a good level that is balanced.
 

elemental

Wherever you go, there you are.
Parts
5K small potentiometer
control knob
2-conductor wire (3 feet)
Nice posting. I'm curious and thinking following your method - did you use an audio taper or linear taper potentiometer on the center speaker?
 

GLJones

Active member
I used a linear taper I already had. The adjustment range is a short turn right at the top of the volume setting. An actual volume taper pot might work better, but this works for my needs.
 
Thanks to GLjones for this info. That center speaker has annoyed me as well so I decided to take this on as well. I didn't have a potentiometer laying around but I did have an on/off switch laying around. The pot on amazon is like a month out in my area so I decided to just try this with the on/off switch first knowing that changing the switch to a pot later would be easy since the hard part was splicing wires in the dash. The center speaker pops off super easy. I took a picture since GLjones forgot to. it is below. I also cut the wrong wire and had to do it twice. purple is purple! i mistakenly cut the one closest to me instead of the one closest to the windshield and had to patch my error.

It took me about 45 mins and about half of that was redoing the wrong wire I cut. Purple is purple. However my mistake is that there is purple on the front and purple on the back of the speaker! I just saw purple and cut and ended up cutting the wrong one. DOH!

Installing the switch makes a big difference and the switch alone is a good for music to turn off the center speaker.

I would agree however that the potentiometer is a way better idea and now having been a guinea pig for the people that come after us, I would strongly recommend that you get the potentiometer and do it once as the best sound is going to come on a blend of the two working together. Having it totally off isn't optimal. I'm guessing that about 25% on or so from the center speaker would make a big difference versus just having it off.
 
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While I was under the dashboard....

I also opted to use this time to route a 4' iphone cable from the USBc connector in the dash to the row of switches. I found it really annoying that I had to drape a phone cable from the center phone storage area to plug in my phone. I was about to paint it black to hide it but while I was messing about to put in the speaker switch I found an easy path to get the iPhone cable down behind the dash as well. I pried up the dashboard vent to the "left" of the phone storage area and it was an easy drop down to the dash below. I left enough extra cable in the dash that I could pull it out and put it back in easily. Right now there is a temporary zip tie on the end of the phone cable to stop it from falling back into the dashboard. I need to now find some kind of grommet that looks nicer here as my next step but I'm happy to not stare at that phone cable on the dashboard now.

IMG_9205.jpg
IMG_9203.jpg
IMG_9208.jpg
 

Zoomyn

Member
heh - on the fiat-ram promaster it'd be setting a code with a speaker circuit open... (justifies requiring dealer programming to enable more that two speakers)
 

GLJones

Active member
Looks awesome. Sorry about the purple confusion. Since I never disconnected the other connector, I didn't even look at the colors.
Funny about running the iPhone cable. I did the same but all the way down to below the cup holders. I have a 'sticky-pad' between the cup holders where I put my phone and I can use CarPlay with it there with my cable...similar to yours.
 
A note to anyone else who tries this. if you put a switch first and then switch to a pot later, the hole you cut in the blank switch will be too large and you will need a washer to cover the hole! i used the closest one I had at the house and now i'm shopping for a slightly smaller diameter washer to replace the one I used. However, the potentiometer is substantially better than the switch for sound. a blend of the side and the center speaker is far superior to the on/off switch. I'm super happy I did this. Much better. IMG_9326.JPG
 
Hein, I put a 5k pot in. It works but its a tad sensitive. If you make these and print them up, I'll buy one. The hack that I did behind that switch to make the pot fit was something special with the dremmel tool and a sanding bit. One part blind luck, one part don't take any skin off my hands in the process. I'm lucky I didn't burn through to the front but I got it in there. Frankly if you are making this as a part, you would be well served to take two positions in the dash and give it a nice buffer around the switch to work with. Plenty of space there.
 

VanGoSki

Well-known member
We would like to make a kit for this
One suggestion. Instead of having people cut their speaker wire and solder it, find a source for the m and f connectors that plug into the speaker and make a little patch cord that's got the wire running down to the pot. So just plug and play instead of cutting and soldering. I found the wiring to the speaker very tight and awkward working up under the windshield, so I just unplugged it. Much better, but I'd prefer to have the pot.
 

n3ix

New member
5K seems way too large for a speaker Lpad (which is 8 ohms typical). I think that might be why the setting is so sensitive. Of course the typical Lpad is rated for much greater wattage then your pot so keep an eye out and make sure it doesn't get hot it you crank up the volume!
 
I'm not sure VanGoSki's suggestion would work. The only real easy way to get the wire down from the speaker to the back of the dash was gravity. I guess perhaps you could use a small plastic rod or something to find a path and pull it back up but gravity down was far easier. If you had to pre make the wires then you would want a quick disconnect behind the Pot so you aren't having to fish the entire pot down the mess behind the dash. there wasn't a ton of room there.
 

VanGoSki

Well-known member
I'm not sure VanGoSki's suggestion would work. The only real easy way to get the wire down from the speaker to the back of the dash was gravity. I guess perhaps you could use a small plastic rod or something to find a path and pull it back up but gravity down was far easier. If you had to pre make the wires then you would want a quick disconnect behind the Pot so you aren't having to fish the entire pot down the mess behind the dash. there wasn't a ton of room there.
A non-issue. Just use your gravity trick to fish a temporary wire down from the top, attach it to the speaker end of the kit harness and pull it back up. Or use a snake from the top. That's what I did, but I left it as a prewire in case I eventually decide to add the pot.
 

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