Hi, I have a Mac Pro running Yosemite 10.10.15, and I'm having trouble with firewire. With Logic Pro, I'm able to choose what channel I want music to come through on my Studiolive 16.0.2 mixer, but when I use Youtube, or anything else, I can only get sound through channels 1 and 2. Does anyone know why this would happen, or how I can change it to a different channel? All feedback is appreciated.