Stu:
I don't know the answer to that question. I suspect it goes something like this: The 2820 GPSR simply acts as a 'network gateway' between the various Bluetooth devices. It connects them all together very well, but it doesn't do anything other than connect them.
So, the analogy is like this: If you went down to the local electronics store, and bought two landline telephones (old fashioned desk telephones), would you be able to connect the two of them together with a wire and then have a conversation from one end to the other? No, because there would be no amplification system in between them. I think the same is true for two headsets (helmets) that are hooked up via the 2820.
I do know that if you have the WCS-1 audio system that is sold by BMW, you can pair one (only) of the helmets with the GPSR, and it will cope with all of the GPSR functions (route guidance, music player, speed camera alerts, phone calls), and you can also pair that same helmet with another WCS-1 helmet, and it will work as an intercom between rider and passenger. But, in this specific case, BMW has designed the helmet to support two Bluetooth sources at the same time.
I have a small over-the-ear Bluetooth headset that is designed for use with a cell phone (you know, the kind that you see every twenty-something wearing on the subway on the way to work in the morning - all looking like they are on their way to a Star Trek audition). I can pair that up with the GPSR and it will function just fine - same as if it was a helmet - but I can't pair two of these things up with each other and use them as walkie-talkies, as you would want if you were setting up a rider to pillion intercom.
I have suggested to Garmin that the explore whether or not the GPSR could support something like this, but I kind of suspect - even with my very limited knowledge of electronics - that the GPSR could not support the hardware end of things, meaning, the switching and amplification. However, that is just a guess.
Michael
