2020 Mercedes Hymer MLT580 audio system upgrade

[AlisonS]

Hi The door speakers on our Sprinter based Hymer are barely audible even using balance and fade on the head unit to the extreme. This means the front cab lacks sufficient bass even with controls turned up. Does anyone have advice of how to get them functioning? I've been to an audio specialist for a complete upgrade but he thinks there may be an amplifier hidden away by Hymer that could be adjusted but I can't find it under the front seats. Replacing the door speakers is unlikely to help until they start gettingsufficient power to them. Has anyone got any knowledge about the MBUX system. It's got other speakers in the dash and at the rear behind the bedheads that are all sounding acceptable.

 

[Brains]

2018 MLT 570 owner here.

My experience of the Zenec unit is it's rubbish.
You may well be far better off simply replacing the entire thing with one made by a reputable company such as Pioneer or Sony.

Expensive option, but probably makes sense in the long run.

 

[Louie25]

Hi, we have a Sprinter based 2020 BMC T600 and ours sounds exactly as you describe too. I’ve played around with settings to no avail and have now just come to the conclusion the door speakers aren’t connected at all.
I think if I put music on my phone and sat it in the cup holder it would sound the same or better even!

I’d be very interested if you find a solution

 

[AlisonS]

Hi, we have a Sprinter based 2020 BMC T600 and ours sounds exactly as you describe too. I’ve played around with settings to no avail and have now just come to the conclusion the door speakers aren’t connected at all.
I think if I put music on my phone and sat it in the cup holder it would sound the same or better even!

I’d be very interested if you find a solution

I’ve got good news - apart from all the front speakers are poor quality the central speaker on the dash close to the windscreen is what’s making things even worse. Gently prise off the grid then prise out the small speaker from its rubber mounts. There’s 2 connwxtions to the speaker. Disconnect one of the wire connections (I think the purple?) which is the sound system. If you disconnect the wrong one it will mean speaker connected only to music system and the phone calls etc won’t be audible. Once you’ve disconnected the sound system wire from the absolutely pathetic central speaker, things suddenly sound considerably better, you can hear the door speakers and the balance, fade and bass and treble controls are more effective. Just upgrading the door speakers and tweeters to the sides of dash and putting in some door insulation will now probably be my next step before worrying about amps and subs. I can’t believe Mercedes have installed such a load of poor quality components.

 

[AlisonS]

2018 MLT 570 owner here.

My experience of the Zenec unit is it's rubbish.
You may well be far better off simply replacing the entire thing with one made by a reputable company such as Pioneer or Sony.

Expensive option, but probably makes sense in the long run.

Ours is a more modern Mbux system which is a very good integrated head unit. See later post….

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[Abgs]

I've had my 21 Sprinter Hymer Grand Canyon S in pieces upgrading the MBUX system.

I used an Alpine Mercedes Sprinter specific system, see here:

Sprinter Audio Upgrade

This document might be useful as it shows where in the Merc wiring loom the connections are.

Wiring Instructions

However if you have the fancy Hymer TV / Audio system where the TV hijacks the cab speakers when turned on the you will likely have a processor / amplifier box somewhere after the MBUX head unit but before the speakers.

I had this on my old Fiat Hymer A Class and sometimes the sound would drop which required the processor box to be rebooted. I think its called a Caratec DSP box?

Using the wiring instructions link you might find the DSP box at the connection point for the Alpine Amp - so basically under the glove box in on the passenger side if you are right hand drive. If you find it turn it on and off again !

 

[Abgs]

I’ve got good news - apart from all the front speakers are poor quality the central speaker on the dash close to the windscreen is what’s making things even worse. Gently prise off the grid then prise out the small speaker from its rubber mounts. There’s 2 connwxtions to the speaker. Disconnect one of the wire connections (I think the purple?) which is the sound system. If you disconnect the wrong one it will mean speaker connected only to music system and the phone calls etc won’t be audible. Once you’ve disconnected the sound system wire from the absolutely pathetic central speaker, things suddenly sound considerably better, you can hear the door speakers and the balance, fade and bass and treble controls are more effective. Just upgrading the door speakers and tweeters to the sides of dash and putting in some door insulation will now probably be my next step before worrying about amps and subs. I can’t believe Mercedes have installed such a load of poor quality components.

I've also done the centre speaker mod - its make a huge difference as does soundproofing the doors. Stopping the Remis door blinds from rattling when you turn the tunes up also helps!