When you are talking to just one friend, microphone position and the loudness of your voice is no problem. If you're too loud the friend can simply reduce volume or enhance it if your voice is not loud enough or the microphone is not directly in front of your mouth.
But when you are riding with more than one buddy, and one has a loud voice and one's voice is very low, this is a problem!
So please add the possibility to reduce microphone volume in several steps (like 10 or so steps), I'd say in the configuration menu or (with the 20S) in the App, so that we can adjust our output volumes to one level.
