OK I have connected my ATV4 to my Vizio TV through an HDMI input. I have the Bose sound system connected to the Vizio TV though an optical cable since the Bose has no HDMI inputs. My Vizio TV supports ARC. I have the Vizio TV speakers off. THE SIRI REMOTE THAT CAME WITH THE APPLE TV DOES NOT CONTROL THE VOLUME. The bar on the screen moves but volume does not change. Surely the ATV4 should be able to make the volume louder and softer??? When my computer is air-playing music the volume changes when I adjust it through iTunes. I should be able to leave the receiver volume constant and change the volume using the ATV4, right? It is a computer after all just like my Mac and should let the volume go up and down just like the Mac does with iTunes. Please give me your input, it's driving me crazy. On a separate note the Vizio TV turns ON with the ATV4 but not off when ATV4 is sleeping... Minor issue but if anyone knows a solution it would be helpful.