Hi All, I've searched all over but I cannot not get this figured out. When I'm using my 2012 iMac I select airplay mirroring (at the top right) to my apple tv. The video and the sound transfer to my TV/Apple TV. I still see the video portion on the iMac. However, I don't get sound on the iMac, only on the TV. Is there a setting where the iMac and the TV show both the video and play the sound? Thanks!