MMI 3G High Plus Nav OEM Audio Integration Holy Grail (forget mObridge)

**jackstone** · 11-10-2020 06:02 PM

I read many forum and everyone seems to agree there is no way to upgrade the MMI 3G High Plus Nav audio system other than taping to the speaker wire and try to feed an aftermarket amplifier with it...

Until now...

I bought this:

Out of eBay. (look for Adapter Trioma "MOST-RCA 3.0"). It cost less than half of what a mObridge cost, and the mObridge is well known to now work with the more recent MMI versions. But this Russian-made converter do work! You only have to plug it into your MOST optical chain using this kind of cable:

and it will provide CLEAN line level output for front/rear and sub without any crappy factory equalization, DSP or time alignment. The signal is flat from 20hz to 20khz, so it is perfect to feed an aftermarket amp with built-in crossover and get the audio upgrade you're dreaming of. It really work plug and play, and I did not lose any of the car feature, even the radio tune still work (as you may know the tuner is integrated with the stock amp in the trunk). And the audio quality is unbelievable.

**bruce_miranda** · 11-11-2020 08:25 AM

This has been around for quite a while and loads of people I know have used it. How do I know?
I do an Audi OEM amplifier connector break out board which allows you to feed your after market outputs back to the speakers without needing to change the plugs or wiring.
Yup, as you said, that kit does work well.

**jackstone** · 11-11-2020 08:59 AM

Glad to know! I was looking for this since a while and everyone only talk about mObridge and Helix. The mObridge did not impress me and barely work in my B8.5 A5, but this kit is flawless.

Also glad to know more people are aware of true audio integration solutions for Audi exists, because working with speaker level input from factory amp is never good at my opinion if you didn't like the OEM sound at first.

We need to share this kind of information to help other people out.

Originally Posted by bruce_miranda

This has been around for quite a while and loads of people I know have used it. How do I know?
I do an Audi OEM amplifier connector break out board which allows you to feed your after market outputs back to the speakers without needing to change the plugs or wiring.
Yup, as you said, that kit does work well.

**bruce_miranda** · 11-11-2020 11:31 PM

True and when you use it with the breakout board. You can have a nice clean install as well with no factory harness splicing cutting etc.

**Mijos87** · 11-12-2020 09:16 AM

Where do you find that board?

Sent from my iPhone using Audizine

**bruce_miranda** · 11-12-2020 10:42 AM

I make and sell them. And when you combine that with the male plug that you can buy via Audi or Aliexpress you can even have it plugged back to the amplifier too.

**Mijos87** · 11-13-2020 04:03 PM

I’m not exactly following, I would possibly but the board from you, then buy that connector but how would that go into the amp?

Sent from my iPhone using Audizine

**bruce_miranda** · 11-13-2020 04:20 PM

May be these pictures in this thread make it clearer.
https://www.audizine.com/forum/showt...nterface-cable

The connector on the board takes the harness connector that would normally have been connected to the OEM amplifier. That instantly gives you access to power and all the speaker wires via the terminal blocks (or soldered wires).
If you do need to go back to the OEM amplifier from the break out board, you attach the wires from male plug that you can buy from Audi or Aliexpress.

**Alpina68** · 12-10-2020 08:13 AM

Originally Posted by jackstone

I read many forum and everyone seems to agree there is no way to upgrade the MMI 3G High Plus Nav audio system other than taping to the speaker wire and try to feed an aftermarket amplifier with it...

Until now...

I bought this:

Out of eBay. (look for Adapter Trioma "MOST-RCA 3.0"). It cost less than half of what a mObridge cost, and the mObridge is well known to now work with the more recent MMI versions. But this Russian-made converter do work! You only have to plug it into your MOST optical chain using this kind of cable:

and it will provide CLEAN line level output for front/rear and sub without any crappy factory equalization, DSP or time alignment. The signal is flat from 20hz to 20khz, so it is perfect to feed an aftermarket amp with built-in crossover and get the audio upgrade you're dreaming of. It really work plug and play, and I did not lose any of the car feature, even the radio tune still work (as you may know the tuner is integrated with the stock amp in the trunk). And the audio quality is unbelievable.

Where can I get this cable and does this bypass the oem amp and i can remove it or does the oem amp have to stay plugged in?

**demi6ix** · 05-12-2021 11:14 PM

Following 👍🏾😬

**StaudiA6** · 08-14-2021 01:51 PM

Originally Posted by bruce_miranda

May be these pictures in this thread make it clearer.
https://www.audizine.com/forum/showt...nterface-cable

The connector on the board takes the harness connector that would normally have been connected to the OEM amplifier. That instantly gives you access to power and all the speaker wires via the terminal blocks (or soldered wires).
If you do need to go back to the OEM amplifier from the break out board, you attach the wires from male plug that you can buy from Audi or Aliexpress.

Bruce, Would like to learn more on your Audi audio knowledge. I am researching the needed items to begin my Audi 2018 A6 base audio system install with the MMI 2G version. If I could install my new Hertz components using factory wires and have the cross overs in the trunk with amps that would save a lot of time. If that what the break out board does?

**bruce_miranda** · 08-14-2021 03:00 PM

Yes it can do that. But have you checked if your amp has the 38pin plug. Also just bear in mind that you can have the crossovers in the boot only if you have separate speaker outputs from the factory amp to the factory speakers. If the speakers split between woofer and tweeter in the doors, running off the same factory amp output, then you can't.

**StaudiA6** · 08-17-2021 02:46 PM

Trying do determine which plug I have. I have the base system with MMI 2 and not sure where amp is located. I would probably be better off running new wires to eliminate any problems with crossover and have the option to go active if the desire should occur down the road. I know from a previous install in a GMC truck that it can be a pain getting wires into door. I guess that is part of upgrading.

**bruce_miranda** · 08-17-2021 03:28 PM

Audi only uses passive crossovers mounted on the speakers themselves. So there are no crossovers hidden in the wiring of the car. Most channels are actively crossed over at the amplifier. But in some places there is a passive crossover employed to split a mid/woofer into a tweeter.

**StaudiA6** · 08-21-2021 09:08 AM

I appreciate all the info. So tough to find much out before tearing into a car without contacting a pro installer. I am interested in how well the Trioma works from anyone in here that have purchased beyond the OP. Want to have very good SQ setup in this car. Seems to be pretty sound acoustically with the stock stereo so I have high hopes of being able to build something that sounds great. The Trioma is less than half price of other signal converters I have been looking at. Will be running the fiber signal into a Hertz DSP so I donÂ’t think the price difference would be a huge factor.