assuming you are talking about bike to bike
I decided to comment on how well I think bluetooth works for bike to bike communications. all of the units obviously have other advantages such as hearing your radio, hearing your phone, gps, and so on. talking on the phone, the noise canceling at least using the SMH10 and an iPhone5s is excellent. Those are all good things as others have mentioned. I was just going to talk about using it for bike to bike.
I have in the past had the Interphone F4, and now have the SMH10 and for a blue tooth intercom it is great.
as for how bluetooth intercoms work as a wireless communications solution. Well, that depends. If you have some good top of the line units they will have really good quality and good speaker volume etc that is a given.
I think bluetooth works best if you are on the same bike or ride relatively close together. when riding with my girlfriend (her on her bike me on mine) (we do ride two up but very rarely) this also works well but when I ride with her we ride slow and we can be quite close together and rarly does the intercom disconnect or get lots of static. The range no mater what they say is in my opinion small. My girlfriend and I rarely get separated by a few trucks for instance but when we do it does introduce static or completely drops it. that said it is very good and being full duplex (like a phone) it is natural to use.
When I am riding with my friends we don't ride as close, for one thing at faster speeds you need more spacing. we are more aggressive and often in the woods as well. either way when their is something between us such as the trees in the bend etc. or just space as we are running at our own pace. this causes static to come across the thing and or it disconnects and you have to do something (depending on make and model) to get them to connect again. this is quickly annoying. the SMH10 is supposed to reconnect automatically and most of the times it does this unless something weird happened or you have been disconnected for a longer time.
A prefered solution to me and some of the guys I ride with is a 2-way radio. as I am a ham radio operator as are some of the guys I ride with then I use my 2-meter handy talkie but a simple FRS radio (costing as little as 20 bucks) is an ideal solution. I realize that most people are not ham radio operators (license required, expensive equipment, legal penalties for cussing, etc) this is where FRS comes in as anyone can pick up a radio and use it.
As for how to talk with the radio while riding for that I use a Sena SR10 which is a little bluetooth enabled device to connect my SMH10 to my 2-way radio. (by the way the SR10 will work with any bluetooth headset not just Sena) so I get the benefit of hearing my music, gps, phone etcetera and having no wires connected to my helmet. All the while instead of connecting the intercom to Rich I just connect it to my SR10 and anyone on the frequency I can talk with. no connect, disconnect, pairing etc.
the advantage hear is also much much grater range. this also alleviates the one brand of device talking only to the same brand. though some of them are coming to the point that they can talk to other brands this is not universal. also no limits to who can be on the same frequency where as I believe my SMH10 is limited to three. and it is PTT (Push-To-Talk) which I prefer, though you can use VOX if your radio has it. I noticed when first riding with Rich actually that I tend to mutter to my self offered kind of under my breath (years of feeling like I am in my helmet with my self I suppose) but the SMH10 is good enough that it picks this up and well it is annoying to me and I must assume it is annoying to others. having the convent button is much better.
Mind you the 2-Way radio solution is Simplex meaning that only one person talks at a time. while talking you don't here what others say. this is actually not a problem and in someways a benefit but you should be aware of it.
By the way the SR10 does not have to be installed on a bike. it has it's own battery and is designed to be portable to use where ever you like. another advantage as I see it.
The short is for bike to bike (other than with my girlfriend, basically puttering around) I prefer the using of a 2-way radio over bluetooth intercom. however in some circumstances the bluetooth intercom works very well and might just be better.
Another note on how the SR10 works, I can connect to it for the 2-way with everyone else but also connect to my girlfriend via the bluetooth intercom (she stays near me and it is always on so she hears my intimate little grunts and things) it is like being at a party but having a private side conversation.
well there is my nickel's worth, here are some links
SMH10 - Sena
SR10 - Sena
my radio setup
https://youtu.be/gqQuSHKLLHM
Ritch
https://youtu.be/CB7vUWR7SyM
while I am not trying to stump for a brand here as for brands I would have to say that Sena is by far the best software and electronics wise that I have ever come across. I am sure that others will catch up or eclipse them in the next few years, then back and forth, and back and forth and in the end We win! keep fighting for our dollars you manufacturing guys
