An audio device, having a primary channel count, which is configured to amplify an audio signal supplied from a source device so as to output the amplified audio signal via a plurality of audio output terminals (23a, 23b, 25) adapted to be connected to a plurality of audio output-targeted devices (24, 26, 40) having secondary channel counts, said audio device comprising: a memory configured to store a plurality of audio reproduction ability information describing the primary channel count and the secondary channel counts supported by the plurality of audio output-targeted devices (24, 26, 40); an input part configured to receive and store the audio reproduction ability information describing the secondary channel counts supported by the plurality of audio output-targeted devices (24, 26, 40) in the memory, thus providing the source device with the audio reproduction ability information indicating a maximum channel count among the primary and secondary channel counts, and to provide the source device with arbitrary audio reproduction ability information representing an arbitrary channel count which is selected from among the primary and secondary channel counts except for a smallest channel count among the primary and secondary channel counts; and a signal processor which is configured to perform down-mixing on the audio signals supplied from the source device in accordance with the arbitrary audio reproduction ability information with respect to the audio output-targeted device (24, 26, 40) whose secondary channel count is smaller than the arbitrary channel count, and which is configured to perform signal processing on the audio signals supplied from the source device in accordance with the arbitrary audio reproduction ability information with respect to the audio-output targeted device (24, 26, 40) whose secondary channel count is larger than the arbitrary channel count. a memory configured to store a plurality of audio reproduction ability information describing the primary channel count and the secondary channel counts supported by the plurality of audio output-targeted devices (24, 26, 40); an input part configured to receive and store the audio reproduction ability information describing the secondary channel counts supported by the plurality of audio output-targeted devices (24, 26, 40) in the memory, thus providing the source device with the audio reproduction ability information indicating a maximum channel count among the primary and secondary channel counts, and to provide the source device with arbitrary audio reproduction ability information representing an arbitrary channel count which is selected from among the primary and secondary channel counts except for a smallest channel count among the primary and secondary channel counts; and a signal processor which is configured to perform down-mixing on the audio signals supplied from the source device in accordance with the arbitrary audio reproduction ability information with respect to the audio output-targeted device (24, 26, 40) whose secondary channel count is smaller than the arbitrary channel count, and which is configured to perform signal processing on the audio signals supplied from the source device in accordance with the arbitrary audio reproduction ability information with respect to the audio-output targeted device (24, 26, 40) whose secondary channel count is larger than the arbitrary channel count.