OK. I have a customer that in their Master Bedroom, they have a 7.1 surround with several input and a tv. When they have guests over, the 7.1 speakers are too loud and disturbe the guests in the room above them. At these times they prefer to have the TV as the primary endpoint. When there are no guests they want the 7.1 as the primary audio. What is the most reliable way to give them the ability to choose which audio they want to use?