Akai Advance problem when slaving Ableton
I'm trying to slave Ableton Live 9 to my Korg EMX-1 through the MIDI IN on my Akai Advance 49. The Advance is connected via USB to the computer. I'm trying to get Ableton to sync to my Advance, which syncs to my EMX-1's via MIDI. Ableton syncs and follows the tempo of my EMX-1 and all bpm changes. But when I choose External in Ableton the sound is chopped of on my Advance, only playing short "blips" of the sounds that it is controlling.
Any ideas on how to fix this?!