Of course! You just set up different activities - one that uses the TV for sound and another that uses the A/V receiver. The trick is being able to shut off the TV sound if that's an issue. You can add commands to the entry and exit of each activity so it can be done but it gets tricky if there isn't a simple command.

An alternative is to simply use the A/V receiver all the time - you get better sound and don't have to worry about flipping the TV sound off and on. Remember, you don't have to turn the sound up.