Hello all, I happily own a 2008 E60 530i M-Sport with factory fitted Hifi Audio with CCC system.
I recently installed a Linux touch screen which has android auto/car play built in and does everything that any android unit would do, but dependant on the phone (my choice, no issue there)
As most of you may know, these units connect to the AUX input to play audio. And it is evident that no matter how much I play with its built-in DSP EQ, the audio is just not as good as the Factory fitted Harman Becker system. Its very evident when I switch between the screen (aux input) and a CD or Radio even.

My question: How can I connect to the direct audio system without going through the AUX input? What my research says is that I have to find a way to connect to the Fibre optics cable. What is my option with my current setup?

My reasearch so far took me to mr12v MOST adapter, but that is essentially its own eco system with its own carplay/adauto imulation to the Factory screen. I dont require it since I already have those features in my current Linux screen. Just want the Linux screen to play audio through the factory DSP Hifi system.

And yes, I dont want to just mess and screw up my wiring, I want a neat, clean connection. Kindly help with your expertise.

E60 CCC with Linux touch screen upgrade.

 

In my opinion, the best way to have approached this would have been to do the following:

#1. Do a full CIC Retrofit (Plenty of threads on how it is done successfully)
#2. Purchase a COMBOX (BN2000) and code it for the E60 (slightly different approach vs. E9X guys)
#3. Purchase a Linux based system specific for CIC

Purpose being, you need to connect to your car via Bluetooth streaming for best sound quality. You would then connect to the Linux unit which leverages the Bluetooth connection you made with your car to transmit the signal to the COMBOX (The fibre optic connection you are seeking)>hifi-AMP>Speakers.

For my car, I have a 2010 which came with a CIC unit, HiFi. All I did was purchase a COMBOX, coded it for an E60. I then made sure that I was able to stream music from my phone to the car. Once I verified that connection, I then purchased a Linux unit specific to the CIC (4 pin LVDS connection, your unit may have a 10 pin LVDS for CCC systems). Within the Linux unit itself, there is an option to use the car's Bluetooth:

 

Year I understand what you are saying. Honestly, this was the very first mod I did to the car, and it was also an urgent necessity because the road network where I live is quite complicated, and E60 doesnt really allow a good phone-mount location. I only researched on the Compatibility, screen being good itself, and a study bitween android and linux systems. With time only I kinda started feeling lacklustered with the audio quality. When I switch to CD or Radio even, the Audio quality is substantially better with the now-almost 18 years old Harman Becker amp.

Now looking at the image you have attached, I remebered that I also do have that Bluetooth option on my screen (I think the core firmware of these units are mostly the same)
I did try it out, but it didnt work for me, probably because my car does have bluetooth but only for calls.


Linux CÇC screen with Bluetooth menu
(Scratches are on the screen sticker, not the display itself - for all OCD guys like myself )

Since I am at this stage now, what would be the best option to reach to the optimum sound quality?

1. Is it possible to code or emulate the OEM BT module to somehow receive Phone and Music? (dont want to use an AUX to Bluetooth or an FM transmitter which will hinder my goal even further)
2. Or will a RCA to Fiber converter (and use the CD changer input) will work? Coz COMBOX is no use for me at this stage for its functions and cost, I feel.

 

Option #2:
According to my research, there is some attenuation that might happen along the AUX channel because of 2 small capacitors in the connector. There has been some controversy over removing these filters from the electronics. Some feel it is a safety measure that BMW put in there, some don't. I'll refer you here to do your own research on the pros/cons of doing this mod. Just be sure you are able to solder back the capacitors if you don't notice a difference. This post has a good summary: AUX port

This picture is from a post by @discs4sale who started a thread on here on how to remove the AUX port. Have a read of that too: Remove Aux Port (2008 E60)

 

@nikey22 thank you! Yes that could make sense as often aux ports have filters to eliminate the noise, which also could result in a quality loss. But often older aux ports were configured to have less quality anyway, as back in that time Aux ports were not widely associated with Dolby Atmos, Wide band stereo, etc. technologies for common users.

Im fairly familiar with soldering but not this much of micro-level. So better not mess with it I feel. And I am not sure yet how, but my linux system works in Aux mode, but without the physical Aux cord connected. Either the custom harness adapter came with the screen is doing something, or the previous owner has done some modification (which I did not see at all during the observation during careful installation of the linux screen myself)

 

Another idea comes to mind. My Linux system has 2 USB ports as I'm sure yours has as well. One is for wired CarPlay/Android Auto, and the other is for general USB use.
Even bluetooth audio is not that great, it is bitrate compressed. If you want the best sound, download all music in .WMA 16bit lossless and see if the Linux system plays it. I know the CIC systems play it natively, unsure about CCC systems.