OSX sound output split across two USB devices <p>If two headsets are both connected to USB ports in OS X, the Preferences => Sound => Output pane only allows the user to select one of them at a time.</p> <p>I thought at first that there might be a way to "split" the output so that both USB devices receive it, as one can do with minijack-headsets connected to the audio output jack using a splitter. But I find that using a USB hub does not change how the operating system treats the two devices as distinct.</p> <p>However, is there a way to direct the same output to two or more devices simultaneously?</p>