First things first: Adding an Amp

erik.wahlstrom

Well-known member
OK, here goes. I've been reading a lot. One of the first things I'm going to do is add an amplifier and rear speakers. While I think I've done my homework (fuses, wire gague etc.) I'd like some help. I have the 7" MBUX and my goal is to add 4 new speakers. 2 to replace the doors and 2 6x9s in the rear. Ideally I'd do this from the house battery, but since the HU is run off the starter, I'm not sure what I want to do is possible.

The plan would be to mount the amp behind the driver seat pedestal. From there run four conductor wires to each door speaker. Four conductor because I'll use 2 wires to tap into the existing speaker wires to act as inputs to the amp, the other two will then drive the speakers. I'll then run two conductor lines to the new rears. It should work right?

The Amp has self sensing circuitry to turn on when it senses a load from the factory HU.

Now the question is where do I tap in? Can I use the house battery (I have one under the passenger seat). Or it there a better place. Thanks for the help.
 
I put my amp in the dash after I removed glove box for access, easy. All the speaker wires are right there coming out of head unit, No need to run wires everywhere. Also look at the Schose 9 conductor cable, will make life much easier. Give a consideration to replacing head unit if you have the crap head unit. I put in a clarion double DIN, looks great, back up camera ready, can watch DVD on it, can output DVD signal to another screen etc.
much better power etc.
 

erik.wahlstrom

Well-known member
Hmm. I took you advice and removed the glovebox. Seems like a dead end. The box comes out and the “cubbies” on either side. The central speaker grill pops out too. But I don’t see a good way to get behind the HU and even so, it doesn’t look like there is a ton of space. 79D3538F-3981-46A4-8AED-8D4EB747B0BF.jpeg
 

erik.wahlstrom

Well-known member
After about 20 torches screws and 5 or so panels removed I convinced myself that further exhumation of the dash wouldn’t do much. Pulling out the glove box does expose an easy path to run 4 conductor cables across the dash which should enable my original plan. Here’s a better picture the free is a fish tape5FD1B59B-2DA0-4346-9295-E092F6F0F822.jpeg
 

430 hp 70

'19 144 Gas Passenger - Carlsbad
Everything you want will work. No issue powering the amp from the house since it will only get signal from the mbux. If you were running a combo of stock and amp powered speakers, running off different batteries might cause them to turn on and off a second apart which is annoying. Powering from one battery and using signal from another is not an issue. Plus if your amp has an aux input, you can play music without the mbux playing.

Sumfuncomet, is yours a vs30?
 

erik.wahlstrom

Well-known member
Everything you want will work. No issue powering the amp from the house since it will only get signal from the mbux. If you were running a combo of stock and amp powered speakers, running off different batteries might cause them to turn on and off a second apart which is annoying. Powering from one battery and using signal from another is not an issue. Plus if your amp has an aux input, you can play music without the mbux playing.

Sumfuncomet, is yours a vs30?
Awesome, this is exactly what I was planning. Any suggestions for which power point to tap into?
 

erik.wahlstrom

Well-known member
Change of plans, it looks like it may be easier to place the small amp in the driver side pedestal. It will fit if cut a piece of 1/4" ply and mount it over the opening. Something tells me this is a bad idea but . . why?
 

72chevy4x4

Well-known member
high power amps need air flow to cool. if that's an issue in your case, consider a method to let air flow around it. there is a foam 'lid' that could be left off to allow the air to circulate.
 

simond

New member
I have been very irritated by poor sound since I received my 519 in late 2018.

The first thing I tried was what I usually do in a van, fit a pair of JBL Control 1s onto the bulkhead above the seats, disconnect all the factory speakers and wire direct to the new ones. The sound this time was terrible, there was a big peak in the upper bass that couldn't be tuned out on the MBUX basic three band Eq menu.

So then I tried a set of B&W monitor speakers I had lying around and these were just the same.

I thought it might be the 'dome' shape in the roof headlining so I mounted the speakers behind the seats.....but it got worse.

This is where I stopped fiddling, hoping someone on here would find a way of disabling the rubbish inbuilt DSP processed signal that MBUX sends out. In other words, a straight through or 'direct' setting. Alas, no such solution has been uncovered afaik.

Looking on the Mercedes Upfitter portal, it would appear that even if an RV converter wants to add their own audio, there's no 'clever' way of doing it, all Mercedes will supply is a plugset in the loom, as a factory option. This merely acts as a insert/break in the speaker output cabling from the MBUX amp to the fitted speakers.

So it seems that if I want to manipulate the signal I have to take it at speaker level and run it through a DSP amp of my own. I think I may have found just such a device in the form of a Pioneer DEQ-S1000A. It appears to give 31 eq channels and some sort of iPhone app that hopefully will do the EQ automatically.

From a hi-fidelity point of view, taking a digitally manipulated signal in an anologue format from MBUX speaker cables, then converting back to digital with more processing (the DEQ-S1000A), then back to analogue again sounds sub optimal.

Has this been tried in the Sprinter? Would like to know if it has been successfully tried before spending more money!
 

Silveringot

8 Grit Sandpaper
I have the 10”mbux and the wires for speakers are directly above the neg batt quick disconnect. Can also find them above the odbII port. Slowly learning this setup. First pic is where ep7 connects but the other wires are there also. Look for twisted wires.

1491FFC4-6EAB-4A65-8B88-5FD513467F4A.jpeg6A6A7C5A-2F8C-4271-8F5C-6490CD44D447.jpeg
 

sanomechanic

Well-known member
Need to run the speaker wire out of the radio into the FIX86.If your factory radio does not have rear speakers then connect left speaker wires with a splice into channels 1&5 and right speaker wire channels 2&6. The run RCA jacks to amp. Even has 2 sub outputs . Crystal Clear hi fidelity digital signal.

I tried an EQ first and could not get a great result. The signal coming out of MBUX is to make those crap speakers work. That signal is trash and needs to be corrected by a digital processor.


I'm 100% satisfied with this product. Worth every penny. I purchased a refurbished unit from creativeaudio.net

 
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sanomechanic

Well-known member
I just realized if I do the house batter thing, I’ll need a switch to the remote wire too.
There is a fuse block under passenger floor under tool kit. To the left below bottom fuse is a place to tap into for remote that comes on in both run and accessory mode. This will not cause any problems with CAN . It's a clean connection
 

erik.wahlstrom

Well-known member
Thanks. I don’t think this is what I want though. My amp owners on when it senses high level inputs. So that works just fine. But when the HU is off I still want to be able to play midis via BT.

so far fronts rears are all working with the HU. I haven’t gotten BT working but should be easy. The heavy lifting is done. And BTW it sounds great with good rears.
 

erik.wahlstrom

Well-known member
Success! Level of difficulty: 4 of 10

I installed new front and rear speakers. It makes a big difference. This turned. out to be much more difficult than planned, but primarily because I'd never done something like this. I spent way too much time disassembling and reassembling the dashboard. Pro-tip, you don.t need to.

The door panels come off easily enough:IMG_7396.jpeg

I made some simple speaker mounting brackets out of 3/16" ply:
F2D0368B-39AA-42FE-BC85-067BB6DF72A1.jpeg

Popped in the tweeters, then ran 4 conductor wires back thorough the dash, through the cable chase and into the driver pedestal.

Tapped into the House battery with a 50 amp fuse (note the picture shows a 30 but it's a 50).
IMG_7403.jpeg

In the rear I used a friend's laser cutter to fabricate some brackets:

1f40c230-90d8-4b27-a453-99b553fffafc.jpeg
Then covered them in foam and fabric.
IMG_7447.jpeg

Mounted them in back and ran 14 gauge wire to the back of the driver pedestal where I'd mounted an amp and a BT Receiver.
 

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