Did not notice that with my 2km, - but yes its primary function is sound.
I did a take with it last year: [nomedia]http://www.youtube.com/watch?v=b7VtJc5WYJA[/nomedia]
Not too much vibration if you ask me ...
I did a take with it last year: [nomedia]http://www.youtube.com/watch?v=b7VtJc5WYJA[/nomedia]
Not too much vibration if you ask me ...