Not sure why Apple chooses to do this but as of now my late 2012 iMac will not allow me to switch to internal speakers when I have headphones plugged into the aux port. I want to purchase a set of wireless headset such as these and would want to be able to switch between headset and built-in speakers on the fly without having to unplug. So what options do I have? The headset supports S/PDIF digital optical output, does this output method prevent the iMac from disabling the built-in speakers option? How are most of you guys handling this problem? Would rather not have to use a set of usb speakers or iMic (as their sound qualities are suspect).