I've experienced this issue with Sena SRL (ver 1.1.2).
GPS (Garmin Zumo XT) is connected to GPS channel. Motorbike TFT is connected to Phone Channel.
When music is playing on phone channel and interrupted by GPS navigation voice indications, the quality of the GPS voice is extremely bad and distorted. When music is not reproduced or paused, the quality of GPS voice indications is not excellent but at least understandable.
Has anybody else experienced this? Any suggestions to solve this?