I have the sena smh10 headsets with an android smartphone and the zumo 660 which all work. I just received the sena sm10 today so both of us can hear the gps and the harley radio using Sena 3.5 jack to 7 pin cable that connects to the SM10.
I'm not sure if I got a defective SM10 but I've tried everything to get the SM10 to pair with the SMH10's to no avail. I use firmware 4.1 for the SMH10's. Anyone else get the SM10 to pair and if so any step by step's would be appreciated.

 

Wife and I have the smh10 headsets. I use a Clear Sound Bluetooth stereo transmitter to do what you are doing. Have no trouble syncing the Clear Sound and the SMH headsets. I've had great luck with their tech support guys, give them a call. Good Luck!