i tested the SRL with my new Neotec II.
I has pairing:
1. a phone and a second phone (as Navigation) or
2. a phone and a navigation system Zumo or
3. a phone (as Navigation) and the FM Radio
It does not matter which variant I use, the announcement quality of the navigation commands is bad and distorted. If I use only one device and at the same time listen to the navigation and music I have no problem.
I think your second Bluetooth is not powerful enough
I hope you has a software solution with the next firmware!!!