This video explains how to connect a Voicelive Extreme 3 and a BeatBuddy, so that the BeatBuddy controls the looper and you can hear the BeatBuddy in the output, be that to a PA or to headphones.
It is important to note at 1:45ish, that as well as midi tempo being switched to 'on', immediately to the left on the screen under 'source' it says 'midi ports'. This needs to be changed from the default 'usb'. I would have put that in the video, but I'm hopeless at this video lark!
Any queries or questions, let me know and I'll do what I can to help.