Hello. When I use LP-16 associated with iMAC and I am replaying playback (video + audio) from the Ableton Live, after some time (depending on the latency setting) begins to rattle sound. How do I get rid of this sound. From the beginning , sound is normal, and after a time slowly goes in rattling. I am using 4 outputs 1/2 synths for PA and 3/4 playback and click for drummer. I have got MacBookAir.