Patent ID: 6868296

Claim:
An audio component system comprising (a) a plurality of components for outputting audio signals, (b) a signal processing control unit connected to the components, the signal processing control unit comprising a plurality of signal input terminals for receiving audio signals from the components, selector means connected to the signal input terminals for selecting the audio signal received by a desired one of the signal input terminals, a signal processing circuit for processing the selected signal and outputting the resulting audio signal, and (c) a control circuit of the signal processing control unit connected to a respective control circuit of each of the components the control circuit of the signal processing control unit comprising signal transmitting means for automatically transmitting at a suitable time a call signal to the control circuit of at least one of the components which is to be checked for connection or non-connection, the control circuit of each component comprising signal response means for sending an answer signal to the signal processing control unit in response to the call signal from the control circuit of the signal processing control unit; (d) muting means, comprised in the signal processing control unit, for automatically reducing substantially to zero the sound volume of the audio signal selected by the control circuit which is to be output from the signal processing circuit when the audio signal selected by the selector means is from the component not responding to the answer signal.