I couldn't figure out why my iMac had no sound and after checking the speakers, power, and cables I went to the System Prefs for Sound and found output set to Soundflower (2ch) rather than headphones. Never had seen this before. I recently recorded something streaming with Snapz Pro X. That is the only thing I can think of that would have changed my sound. But even that was a while ago. Not sure what else I may have installed since then that would have done that. Possibly an Audio Hijack Pro update, but I never even use that. What App typically installs Soundflower? I have never even seen it before in my Sound settings. Certainly not on my MacBook and I'm in the settings all the time messing with Mic volumes and such for better iChats.