Not sure if I'm on the right forum but here is my issue.
I have a 2011 MBP 11" with OS X (Lion) that has a mini HDMI (Thunderbolt) port for display connection. I checked that audio does go thru the HDMI port. So I bought a mini adapter like this one from Amazon:
System Preferences > Displays >> Arrangement >>> Mirror Displays (but know, that the display with the lowest resolution determines the maximum resolution used on both, thus one display will have a lower than native resolution, except when both displays have the same native resolution)
Or you just drag the windows you want onto the TV. It acts as extension as it is currently set up.