[Varjo]

I've been pulling my hair out over this. I really really really want to use TOSLINK or coaxial digital input to pipe audio to the stock radio (professional, non-idrive, logic 7). As far as I can tell, everything is now MOST, so my only hope is to find something like a CD changer emulator that will pipe TOSLINK/coax digital input over the most bus. Unfortunately, I can't find a product that does this. Does anyone have any ideas or has done something like this?

[kaigoss69]

Originally Posted by Varjo

I've been pulling my hair out over this. I really really really want to use TOSLINK or coaxial digital input to pipe audio to the stock radio (professional, non-idrive, logic 7). As far as I can tell, everything is now MOST, so my only hope is to find something like a CD changer emulator that will pipe TOSLINK/coax digital input over the most bus. Unfortunately, I can't find a product that does this. Does anyone have any ideas or has done something like this?

Not that I know of. Doesn't sound there would be a huge demand for something like that. In fact, yours is the only such request I have seen...

[Varjo]

Originally Posted by kaigoss69

Not that I know of. Doesn't sound there would be a huge demand for something like that. In fact, yours is the only such request I have seen...

Hmm, that's a huge shame. It's part of my plan to have a Chromecast audio handling audio streaming. It's far better audio quality than Bluetooth AD2P even with aptx. I have a preliminary set up working now, but I've been highly disappointed with the aux in quality. The Chromecast audio supports TOSLINK out and I'd love to find a way to pipe digital audio into the stock radio somehow.

[kaigoss69]

Originally Posted by Varjo

I'd love to find a way to pipe digital audio into the stock radio somehow.

Why would you want to do that? That's like feeding your dog filet mignon and expecting its poop to stink less.

[kaigoss69]

Originally Posted by ctuna

The mobridge preamp used to do that.
But it cost around 500 bucks I think there is one
other pre amp out now that takes most but again its
expensive.

Not quite, the Mobridge converts the MOST signal output into an input for aftermarket amps. OP wants to be able to input into the MOST loop and playback on OEM system.

[ctuna]

Shoot first aim later
I guess I have been watching Donald Trump to much.

You could get a Dension 500s bt at least its usb direct
to most bus. Or for than matter if you have BMW usb
its still digital direct as much as possible.

[Varjo]

Thanks for the help guys. Sounds like I may be out of luck. I'll try a ground loop isolator on the aux in and see if that improves things.

As for the why, the stock system doesn't sound bad to my ears when playing CDs; I just want that audio quality fromy other sources (also the Chromecast audio is crazy convenient, makes it duper easy for passengers to switch off playing music).

[ctuna]

Aux input is noted to be low fi
Some say feeding it with a high quality head phone dac helps.
and/or described in the following thread.
http://www.e90post.com/forums/showthread.php?t=1002984

See entry 80 and most of agentfishes comments.

[Varjo]

I'll check it out; thank you! It looks like this guy has exactly the same goal as me, but with airplay/idevices instead if Chromecast/Android.

[Varjo]

Ok, looks like I could use something like this: http://www.amazon.com/gp/aw/d/B00934...SXBV6PSR4PVVDJ

Still seems a shame we can't get digital input. I have 6fl, any hope in that avenue (some way to convert TOSLINK to USB)?

[mathematics]

All you can do really is recode to hifi and do something like match pp82 and then you can have a better amp and have your toslink

[Varjo]

Alright, so I bought that DAC I linked above as well as a ground loop isolator. Also bought a 12v to USB adapter in case the car's is noisy.

The end result massively exceededy expectations! Holy crap this sounds so much better; given high quality source I can't distinguish between this and a CD.

[ctuna]

So what is your exact sound chain
From your source music to the aux input I assume.

[maddmatt02]

I don't feel that my cheap little Bluetooth receiver plugged into aux in has SQ anywhere near Bluetooth streaming right to my stereo in my accord... Are you saying you stream music to Chromecast, optical out to that DAC, then the line out from the DAC to the aux in and that makes it sound better?

[ctuna]

Bluetooth streaming is not as good as Wi Fi or USB
the bandwidth is more limited. The big limitation is your
stereo equipment and the source data . And in the case of
a BMW the aux is crappy.
Also any direct analog output form a phone is suspect.

[Varjo]

Originally Posted by maddmatt02

I don't feel that my cheap little Bluetooth receiver plugged into aux in has SQ anywhere near Bluetooth streaming right to my stereo in my accord... Are you saying you stream music to Chromecast, optical out to that DAC, then the line out from the DAC to the aux in and that makes it sound better?

Yep, exactly. The exact chain is:

Chromecast Audio (TOSLINK) -> Fiio D3 DAC (Line Out) -> PAC SNI-1 Ground Loop Isolator -> AUX In.


In order to use the Chromecast you need an active WiFi network in the car. I am using an ATT OBD2 powered hotspot that turns on with the car. I will update this post with pictures of everything later.

A few thoughts:

The Chromecast directly to aux in sounds pretty bad, not sure why. The ground loop isolator helped a bit, but I still wasn't happy.

The ground loop isolator may not be needed with the Fiio D3, the sound with and without is very close. I think I noticed a subtle improvement with it, so I kept it in the chain.

Powering things from a USB charger instead of the car USB port made a small difference, perhaps due to cleaner power or perhaps due to a ground loop reduction.


Here are some pictures of the setup. I have tried to keep things semi neat (I may get a shorter optical cable in the future, but I had this one on hand and it was high quality so I shouldn't have issues with it coming loose). Although it's not exactly an invisible install, it does leave the console pretty much free and still provides access to the cup holder. I used a right angle flat OBDII extension cable and filed a tiny notch in the back of the door to run the cable through. This way I can leave the door cover on and mount the hotspot with a little bit of Velcro.

[maddmatt02]

that seems a little unnecessary to need a hotspot to connect the phone and chromecast audio... wonder why they didnt make it so that you could set up an adhoc network or whatever its called and connect directly to the phone.

[ctuna]

BMW is really behind on car electronics
for entertainment and communication.
It wasn't till 2011 that they had bluetooth streaming
in there cars. Plus when car manufacturers integrate
this stuff into the car they don't consider how easy they
can make it for aftermarket addon's.
It was much easier when the stereo was a standalone
piece of equipment.

[Varjo]

Originally Posted by maddmatt02

that seems a little unnecessary to need a hotspot to connect the phone and chromecast audio... wonder why they didnt make it so that you could set up an adhoc network or whatever its called and connect directly to the phone.

It's somewhat annoying, yes. The issue is that the Chromecast needs both internet access (it streams directly from it's Audio source most of the time) and to be on the same WiFi network as a phone. You may be able to get it working by enabling tethering and using Chromecast guest mode, but it was no big deal for me to add the hotspot to my att account.

[ctuna]

ATT data plan is not cheap
are you streaming from an Internet Service or simply
playiing files from your phone?

[Varjo]

Originally Posted by ctuna

ATT data plan is not cheap
are you streaming from an Internet Service or simply
playiing files from your phone?

You can stream files from your phone to the Chromecast without using any data. I also use some internet radio apps which cause the Chromecast to pull the info directly from the cloud. It's the same as with Bluetooth, you can use local media or data intensive apps. I use a mix.

[Stream]

Mulf2 and mulf2h have aux in which works through ADC. There is I2s bus between ADC and MOST-bus transmitter. So you can use any source with i2s output. I'm planning to mate airplay device (air enabler) and "usb to i2s" transport (based on pcm 2706). I'll report if it will works or not.