I was wondering same thing about internal vs external microphone. Has anyone compared the quality of the external mic supplied with the dudu7 unit to the internal/built in mic? I installed mine with the external mic that came with the unit and would have to pull everything out to disconnect the external mic to compare (unless there is some setting somewhere to select which mic to use)? Was curious if they both work about the same or if one sounded better than the other. By "better" I mean the person you are talking to hears less noise from AC or wind, and overall better clarity of your voice.