A system of wall-mounted audio system zone controllers, each having a digital display of a QR code that is unique to that particular wall-mounted controller. By scanning the QR code with a smart phone, or the like, where that smartphone is connected to the same network as the audio processing assembly that is communicatively connected to the particular wall-mounted zone controller, a user gains access to a website that provides expanded and remote audio control functionality over and above that provided by the wall-mounted zone controller itself. A wireless network router is in communication with the audio processing assembly and with the smart phones used to scan QR codes.