PA does not appear to be adhering to OS X system setting changes for 'sound output' selection, in cases involving external sound devices (such as monitor-based speakers). Scenario: A secondary sound output device (external speakers, in this case) is selected in system settings. PA is started, and at this point all sound is audible from the external speakers. Then headphones are plugged in. OS X detects the state change and all sound is re-routed to the headphones, except for the sound from PA, which continues playing from external speakers. A similar scenario involving internal speakers and headphones is handled properly; the sound from PA toggles back and forth between headphones and the internal speakers, along with all the other system sounds. *Note that the internal speakers and the headphones share a single device designation which toggles its name based on which is available. This is not the case for external sound devices, which are listed individually. Other cases where I've attempted to change the sound output device while PA is running, are handled improperly. It's as though PA is locked on to it's sound output target and isn't adhering to system selection changes between audio output devices 1, 2 and 3. My workaround is to quit PA entirely, select the newly desired sound output, and restart PA. I'd call this one a low priority for me, but it occurs frequently enough for me that it should be reported and probably tracked. Long matches lead to taking uncomfortable headphones off sometimes. =)
It's not only on Mac. Windows version basically have same problem. Use Bluetooth headphones and I'm happy that on Linux there I can re-assign output for applications on my own.
