I would like to share my findings regarding my recent Samsung S10 upgrade to Android 10 and problems with the audio output when using it with my 2019 Ford Edge with the Sync3 system with Android Auto with the phone directly connected ot the car via the USB cable.
After the Android 10 upgrade, I noticed a significant deterioration in the quality of the audio. I traced it to the fact that the Galaxy S10 was using the Bluetooth connection to send audio output to the Sync3 system rather than using the USB cable. I assume with the Android Pie it was using the cable automatically. I worked around the problem as. follows:
1. Connect the phone via USB and. start the car. Wait for Android. Auto to activate.
2. Flip down the settings drawer at the top of the screen and tap the Media icon.
3. Tap the active media app (Amazon Music, Google Play, etc,) and select "My phone" as the output device. This switches the audio to use the USB cable.
After this, the audio output returns to the previously good state I enjoyed prior to the upgrade (louder, more clear sound). It does this for all audio application from then on, until I disconnect the phone. I have to go through this procedure every time I start the car.
I would like to know what changed between Android Pie and 10. I believe the auto audio selection is not working correctly with Ford Sync3 phones.
I could not find a setting under Android Auto to do this. Ideally it would be nice if Samsung Smart Things could work as an Android auto app, so that you could switch it there.