Sena 20S and Mixit

Please help me connect my Sena 20S to my mixit and Garmin 550.

Now, I have the 550, a radar detector, and an ipod hard wired into the mixit, and a dongle as the output of the mixit. My andoid phone is paired to the 550. I am able to pair the dongle with the Sena so i can hear everything, including phone calls. However, how do I get my telephone audio out from the headset to the GPS or phone so other people can hear me?

As far as I know, you can't do that with a Zumo 550 via BT, so either pair the phone directly with the Sena headset or if you want to go through the Zumo you'll need to hard-wire it, including a mic line. Of course that kind of defeats the point...

I use a Sena SM10 BT hub, and a mixer (from AmpliRider) to plug the rest of the gear (RD, Laser Jammer, etc.) into the SM10, including the hardwired Zumo 550 audio output through the AmpliRider for stereo music (as the crappy 550 only does mono via it's native BT). The phone is paired directly with my Sena SMH10R.