[Brendanssound]

Looking to grab one of these fancy Mr12Volt boxes this afternoon. But I really want to upgrade my screen as well. Are there any of those android all in one screen head units
That make use of audio over MOST these days?

I really don't want to have to buy a Mr12Volt AND a larger screen if I can avoid it. And I really don't want to use AUX for audio

[ctuna]

Pretty much every android unit I have ever seen or heard of here uses the AUX
except mr12volt . You never mention if you have idrive but you must if you mention
a screen. OEM screen and idrive system updates might work . You would have to
search the retrofit sites for this and it will be even more pricey.

[Brendanssound]

Yeah that's pretty much what I came to the conclusion of after doing research. Mr12Volt it is.

[DavesZed]

There is always this device....
https://www.xcarlink.co.uk/most-fibe...ml?printable=Y

Basically it converts a 3.5mm AUX input into the fibre optic MOST output, thus you can still have the Android screen replacement, but it'll feed into the MOST network instead of the AUX.

Food for thought

[ctuna]

Looks like it does a subset of what mr12volt does.

Mr12volt gives you usb , sd card, phone with streaming audio and another aux.

Dension 500 was the device that did the this stuff then there was the Grom.
Mr12volt is half the price of these .

[DavesZed]

Originally Posted by ctuna

Looks like it does a subset of what mr12volt does.

Mr12volt gives you usb , sd card, phone with streaming audio and another aux.

Dension 500 was the device that did the this stuff then there was the Grom.
Mr12volt is half the price of these .

Yeah it does, this is what I was looking at prior to finding the Mr12volt, but in my case Mr12volt does more of what I wanted from it, but would be ideal if the OP prefers the Android screen install (Android screens are fixed in the E89 as opposed to the flip-up of the OE screen that I prefer), that way he'd still have the other benefits, all be it converted analogue to digital sound.

[Ali-E90]

If you have CCC, your best bet may be to update to CIC and then get the respective mr12 unit.

CIC screen isn’t too bad, so I imagine that may not be what you already have.

[nthnthnthnth]

If you have an existing Android HU with CarPlay would something like this AVIN part work to connect the head unit to the MOST connection? https://avinusa.com/accessories/most...ace-boxes.html

That said, since the AVIN part is RCA to MOST, would it even matter? Wouldn’t the audio quality going into the MOST connection only be at RCA quality (from a low quality DAC in the head unit) and defeat the purpose of using MOST? Same question for the XCarlinkit device linked to above — it’s a bit hard to understand the point of going 3.5 mm to MOST, especially from a low quality DAC in the head unit. It seems what’s getting fed into the optical connection would already be lower quality. Maybe USB out to MOST would be meaningful, but I haven’t seen anything like that on the market.

[ctuna]

The units you indicated are for turning analog outputs from a head unit to most for
the Logic 7 amp and they only do two channels worth .
If you want to use and aftermarket head unit and don't want to loose the L7 amp that
is what they are for.

The original question was how to bypass the BMW Aux Input for it's known low quality.
So he is asking if there is a digital way in .

http://www.e90post.com/forums/showthread.php?t=1002984
There is a lot about the quality of the BMW Aux connection in the above
thread . Basic conclusions are Aux with Dac a little better, avoiding the BMW Aux best.

[Captain Buumer]

I tried this:

Android screen (3.5mm) output
into
Dension 500S (i own) or Mr12Volt.

This way you bypass the awful OEM Digital analog converter & the quality is not that bad.

[nthnthnthnth]

Originally Posted by ctuna

The units you indicated are for turning analog outputs from a head unit to most for
the Logic 7 amp and they only do two channels worth .
If you want to use and aftermarket head unit and don't want to loose the L7 amp that
is what they are for.

The original question was how to bypass the BMW Aux Input for it's known low quality.
So he is asking if there is a digital way in .

http://www.e90post.com/forums/showthread.php?t=1002984
There is a lot about the quality of the BMW Aux connection in the above
thread . Basic conclusions are Aux with Dac a little better, avoiding the BMW Aux best.

Editing original post: I understand Hi-Fi (option 676) uses an analog connection to the amp instead of digital/MOST, which is a significant downside.

But for the sake of those reading this who have an Android head unit with Hi-Fi instead of Logic7, Hi-Fi does still use MOST for accessories like CD changer, the digital connection just stops at the Professional radio that connects to the amp via analog. https://ia801005.us.archive.org/11/i...munication.pdf. So it seems the AVIN MOST connector could theoretically still be used to tap into the MOST ring and drive a digital signal to the Professional radio, avoiding aux if nothing else. Even with this though, since the AVIN MOST unit uses RCA as an input, it would still use the Android head unit DAC to RCA before going to MOST, and back to analog again to the amp. Assuming it could be done then, for the amount of work involved it seems like a small benefit relative to just using a high quality USB DAC and 3.5mm cable (again, for Hi-Fi not Logic7).

[ctuna]

Actually the analog connection is not a downside by any significant factor
with a standard 4 channel setup from a Head Unit(Pro Radio or idrive). The differential signals keep the noise down
and the BMW Head unit actually is a good pre amp out signal.
Nobody has complained about the output for Hi Fi being a bad signal or in any way
being noisy and many people have put aftermarket amp in . You need to get one that
accepts differential signal though.
There could even be an argument that it's better as there is no processing of the signal
dependent on the quality and design of what in the amp.

Some AUX Inputs in some cars are OK it's just the BMW on isn't .

[nthnthnthnth]

Originally Posted by ctuna

Actually the analog connection is not a downside by any significant factor
with a standard 4 channel setup from a Head Unit(Pro Radio or idrive). The differential signals keep the noise down
and the BMW Head unit actually is a good pre amp out signal.
Nobody has complained about the output for Hi Fi being a bad signal or in any way
being noisy and many people have put aftermarket amp in . You need to get one that
accepts differential signal though.
There could even be an argument that it's better as there is no processing of the signal
dependent on the quality and design of what in the amp.

Some AUX Inputs in some cars are OK it's just the BMW on isn't .

Thanks, this is very helpful. For folks with Hi-Fi then, could the AVIN MOST connector be wired in to the Professional radio at one of the two points circled below? Seems like a good way to get MOST with Carplay.

[ctuna]

Last time any body said anything about AVIN it didn't have a Most connector .
Avin sell and adaptor that converts two channels to Most to supply a Logic 7 amp
that is the only thing that I have seen them do in terms of the Most bus unless
things have changed.

The Avin head unit only have analog outputs and no built in Most function as far
as I know . So Avin cannot put out a Most Signal and the BMW . Mr12volt and Dension
are designed to emulate the CD changer over the Most Bus that is why they
work Avin has not such device.

The most system has a whole computer language associated with both for commands
and signals to devices. Devices have to be built that use and understand that language.

Most
http://www.e90post.com/forums/showthread.php?t=727663
http://www.e90post.com/forums/showthread.php?t=347222
https://www.google.com/search?q=BMW+...VCkMqy2aCK09M:
http://www.1addicts.com/forums/showt...php?p=19256760

[nthnthnthnth]

Right, AVIN and other Android head units generally have only have RCA, 3.5 mm and USB. They cannot put out a MOST signal on their own.

AVIN sells an accessory that converts an RCA connection from the head unit to MOST, so that the head unit can be connected to the MOST bus. https://avinusa.com/accessories/most...ace-boxes.html. The purpose is similar to mr12volt and Denison Gateway 500S -- avoid aux.

I know these accessories can be used with a Logic 7 system. What I am wondering is if they would work on a Hi-Fi (676) system.

BMW's own documentation makes clear there is a MOST bus on the Hi-Fi package, because that is how the CD Changer communicates with the radio: "If the vehicle is equipped with the HiFi audio system, the digital data of the CD is sent via the MOST bus to the radio or navigation system." https://ia801005.us.archive.org/11/i...munication.pdf

If the CD Changer accessory communicates over MOST to the radio on a Hi-Fi package system, it seems like an Android unit using either the AVIN MOST adapter, Dennison Gateway 500S or mr12volt should be able to as well by emulating the CD Changer (just like on Logic 7). It wouldn't connect directly to the amp over MOST, but it still would avoid aux.

That's what I'm trying to confirm.

[ctuna]

Nope the Converter from Avin is only to retain the Logic 7 amp .
It is not similar to the Dension or Mr 12 volt at all.

MOST CONVERTER FROM AVIN ALLOWS ANALOG SIGNALS FROM A
AFTERMARKET HEAD UNIT TO INTERFACE WITH A LOGIC 7 Amp.
IF YOU CHANGE THE HEAD UNIT TO AFTERMARKET YOU LOOSE THE
MOST BUS SYSTEM AS THE HEAD UNIT IS THE SERVER for the MOST SYSTEM.
If you remove the BMW Head unit you loose all the MOST BUS modules
and there functions. The piggy back module avoid this but use the AUX
as a pre amp gateway to the existing audio system . But the BMW AUX sucks .
This is the way people have been using it here , never seen anything else mentioned.

MR12volt devices allow INPUTS TO THE existing BMW Head unit via the MOST SYSTEM to give you additional media sources. (usb ,SD Card , bluetooth phone and streaming , and another AUX) by using the CD changer function.

Most Bus on car with 676 is to communicate with Telephone unit , Mulf module
, Satellite or equivalent Euro module , CD changer it has nothing do with
the amplifier which is totally analog in the Hi Fi system. These units feed data
to the Head Unit through the Most System .
In the base system which has no amp there is still a most system for these
modules . The Most system is independent of any amp communications
or interaction in the 676 system as well.
The only exception is the Logic 7 amp which only gets data and controls from the Head unit via Most.

As far as the Head Unit and Amp go it's totally analog in the Hi Fi system.

BMW stereo types
http://www.e90post.com/forums/showthread.php?t=352586
http://www.e90post.com/forums/attach...2&d=1266451970
http://www.e90post.com/forums/attach...2&d=1260829447
http://www.e90post.com/forums/attach...1&d=1209780865
http://bmwcoders.com/forum/3-er-8/bm...1-e92-e93-291/
http://technicpnp.com/menuDiagrams/d...e90_92_93.html
http://www.musicarnw.com/page-2/
http://www.e90post.com/forums/attach...3&d=1169133185
http://www.e90post.com/forums/attach...1&d=1209780605
http://www.e90post.com/forums/showthread.php?t=641323
http://www.e90post.com/forums/attach...4&d=1278871872
http://www.e90post.com/forums/showthread.php?t=343673
https://www.bimmerfest.com/threads/e...n-752.1275694/

base system wiring pre/post 3/09
https://www.google.com/url?sa=t&rct=...tDpLJPcGkw_ui_
Base System Guide
http://www.e90post.com/forums/attach...5&d=1493273253

It's not clear that the DAC in the Head Unit has anything to do with the loss of
audio quality as the CD player does not loose any clarity . The aux may not even
to through a DAC in the base or hi fi system but instead go directly to the pre amp
in the head unit.

[nthnthnthnth]

Thank you for this explanation. The computer for the CCC/CIC/radio (e.g., 65129199905) is actually retained with an Android head unit (which just replaces the on-board monitor, e.g. 65829211969). I'd understood the MOST gateway was in the computer that is retained, not the monitor, so it would not break anything for MOST, but I am sure I am misunderstanding something there and will take your word for it.

For those with a HiFi system (676), there seems to be minimal difference in sound quality between (1) high quality music files played directly off the car's internal hard drive and (2) a high quality Spotify stream on an Android head unit using a quality external USB DAC to aux. There is a difference, but without playing the same song side by side on each in a parked car it is very difficult to tell. The difference also probably is more noticeable on Logic7 than HiFi. That said, if the main interest is having CarPlay, a mr12volt unit seems to be a better option than an Android head unit with a DAC even on HiFi.

[ctuna]

The Hi Fi system is crap on it's best day .
Power rating for BMW is at 10 percent distortion and they
also use 2 ohm speakers to achieve this. (kind of cheaters trick)
You can not turn up the Hi Fi without is getting distorted
and crappy.
The worst part is the amplifier and the speakers are not that
much behind, still crap .(although the doors sound better with a better amp)

Android Head units come in 2 different types.
The piggyback units which are basically and ipad that feeds the
Aux .(these are sometimes integrated into a replacement screen)
The only one that avoids the Aux is the Mr12volt.
And a complete Head Unit replacement.
If you already have idrive you are pretty much limited to the first type
as there are no aftermarket head units that have a separate screen.
The hump in the middle for the idrive screen would be useless and
annoying if it's just a dead lump.

[ironduke2010]

Originally Posted by ctuna

The Hi Fi system is crap on it's best day .
Power rating for BMW is at 10 percent distortion and they
also use 2 ohm speakers to achieve this. (kind of cheaters trick)
You can not turn up the Hi Fi without is getting distorted
and crappy.
The worst part is the amplifier and the speakers are not that
much behind, still crap .(although the doors sound better with a better amp)

Android Head units come in 2 different types.
The piggyback units which are basically and ipad that feeds the
Aux .(these are sometimes integrated into a replacement screen)
The only one that avoids the Aux is the Mr12volt.
And a complete Head Unit replacement.
If you already have idrive you are pretty much limited to the first type
as there are no aftermarket head units that have a separate screen.
The hump in the middle for the idrive screen would be useless and
annoying if it's just a dead lump.

ok, so if coming from HiFi no-idrive, i read carplay options as:
option 1. use an android head unit like the AVIN and the bmw aux.
option 2. use an android head unit like the AVIN, get a mr12volt, and use (or code and use) the CD changer output.
option 3. replace the HiFi head unit with a carplay replacement headunit.

sound wise, should options 2 and 3 be comparable? they both seem similarly complex, and each has it's own pros and cons otherwise, but from a sound quality point of view, where do i have the best shot at quality sound from carplay apps? (note, i already use a bimmertech sourced PP82DSP and a Technic harness with my normal HiFi non-idrive)

[nthnthnthnth]

Originally Posted by ironduke2010

ok, so if coming from HiFi no-idrive, i read carplay options as:
option 1. use an android head unit like the AVIN and the bmw aux.
option 2. use an android head unit like the AVIN, get a mr12volt, and use (or code and use) the CD changer output.
option 3. replace the HiFi head unit with a carplay replacement headunit.

sound wise, should options 2 and 3 be comparable? they both seem similarly complex, and each has it's own pros and cons otherwise, but from a sound quality point of view, where do i have the best shot at quality sound from carplay apps? (note, i already use a bimmertech sourced PP82DSP and a Technic harness with my normal HiFi non-idrive)

ctuna would surely have more (and better) thoughts here, but HiFi no iDrive seems like it limits your options for CarPlay.

For an Android head unit I think you would be cutting a hole in the dash to install a screen (something like this https://www.e90post.com/forums/showt...hp?t=1785330)?

I believe mr12volt is just a box. If you don't have a screen via iDrive already, I don't see it working out for CarPlay, especially as it sounds like mr12volt will not work with an Android HU.

I think by option 3 you mean retrofitting in an OEM device that supports CarPlay natively, like NBT EVO?

[nthnthnthnth]

Originally Posted by ctuna

The Hi Fi system is crap on it's best day .
Power rating for BMW is at 10 percent distortion and they
also use 2 ohm speakers to achieve this. (kind of cheaters trick)
You can not turn up the Hi Fi without is getting distorted
and crappy.
The worst part is the amplifier and the speakers are not that
much behind, still crap .(although the doors sound better with a better amp)

Right. For stock HiFi systems there doesn't seem to be too much point in trying to use the limited MOST connection that is there, vs aux.

[lnxguy]

I'd worry about a proper DSP for HiFi before I worried about sound quality with a Carplay unit..