Hell all, While using Airflow I noticed I am unable to mute my MAC'S internal speakers so that audio only comes out of my externals via airport express. This has become frustrating since there is a latency issue when playing back through my externals. Can someone help me with muting the internals while streaming audio through the externals? Also, I tried to 'mute' the comps internals by plugging a headphone jack into the comp. Interestingly enough, when plugged into the headphone jack the earbuds acted as a microphone and so did the internal speakers and audio was returned via the external speakers. Can someone explain the theory behind that? thanks in advance to those who respond!