I want to use Android Auto (AA) on my Pixel phone to feed the wireless android AA Adapter I purchased ( It's an Ottocast clone) for navigation and visual music/route selection, but listen to the music and the navigation prompts from my phone, and issue voice commands through, my SENA SRL 1 headset in my SHOEI Neotec 2 helmet.

I was able to pair the Sena with the AA device as a "GPS", but the volume is very low and seems unable to be adjusted using the volume control on either the phone or the SRL. 

Hoping someone is able to offer some guidance on how to make this work properly.

Thanks!