I am a singer who needs to perform online using Garageband tracks. My instrumentation is saved as a backing track on Garageband (which has the filters I need to add to my voice to make up for the fact that the location I have to sing at is less than ideal, acoustically) I've set the output for Garageband to Soundflower ch 2, and BUTT to pick up said input on soundflower ch 2... not a problem. Both have monitor on. The problem? I can't hear the backing tracks OR myself singing. I turn monitor on...and you CAN hear it on the stream I am broadcasting, both my vocals and the backing tracks... but I get none of it back on my headphones. Which... is an issue when you're singing with a backing track.