Back on 27 August, DCarver said:
Well, I'm in the fray now. Sena20S, Zumo 550, Zumo 590LM.
- Audio, music, sounds like crap blue toothed to Send from 550. Horribly bad. Starcomm sounds great.
- Sena20s - no cloning feature? What up with dat? Get one set up, clone to another.. NOPE.
- It's all confusing.. iPhone connected, Pandora going, iPhone to Zumo.. Zumo to Sena.. Results? Crappy audio, better than 550 but far far short of StarCom analog, Zumo550 with Sirius XM.
Not sure how this will end. May need to follow FjRays advice and put .45 in place.
Hopefully you've figured this out by now already, Don, but the Bluetooth output from the zumo 550 is via the "Headset" profile, which is low fidelity, monaural, and duplex. No good for music. The bluetooth input to the zumo is "Handsfree" just to connect the phone to the GPS. There is no A2DP (stereo) profile supported in or out of the zumo 550.
I bought a Sena SM10 Dual Stream Bluetooth Transmitter, which I have hard wired to the stereo output from the zumo 550, as well as the mono output from my Passport Radar Detector. The output of the SM10 is A2DP, so the audio is stereo, and fairly good fidelity, but s not Duplex (bi-directional), so will not pass microphone through back to the phone.
There are two ways to work around the phone connection. If you want to keep the phone display and call screening functions on the zumo 550, go into the zumo setup / bluetooth and select the audio button at the bottom. On that screen set the zumo bluetooth audio output to "Phone only", which will keep the Navigation and Music audio on the audio output jack and the duplex phone audio will be on the Bluetooth. Then pair your headset to the zumo as a phone (headset profile) and the SM10 transmitter as a "media device" (A2DP).
The other way would be to pair the phone directly to the headset and lose the onscreen functions of going through the zumo. I think that method actually works more reliably. In either case, when you are taking a phone call all other audio (music / GPS, or Radar Detector) from the SM10, or intercom audio between headsets will all be blocked.