When I use a VoIP application on my iPhone plugged in with a Lighting cable and Bluetooth enable, the other parties on the call get an echo. When I disconnect the Lighting cable, the echo goes away. This makes me believe there are two systems competing with each other - the Bluetooth audio and the audio going across the Lighting cable. I could buy a charge only cable, but that's yet another compromise I'd have to inflict on my Volt Entertainment System. (I've already abandon CarPlay because of it's lack of reliability and support for more than three useful apps).
Does anyone know the details of the audio path for the Volt entertainment system?