Signal combining circuit signal processing circuit including the signal combining circuit stereophonic audio reproduction system including the signal processing circuit and an audio-visual reproduction system including the stereophonic audio reproduction system

摘要

The signal combining circuit 1 has a first input 2 and a second input 3 and an output 4 which receive the signals having frequencies in the audio frequency spectrum. The signal path between the first input 2 and the output 4 has a first transmission characteristic H1 * H3. The signal path between the second input 3 and the output 4 has a second transmission characteristic H2 * H3. The propagation characteristics indicate inconsistencies that cause a phase shift between signal components passed through the first signal path and signal components passed through the second signal path. The amplitude transfer determined by the transfer characteristics decreases above the predetermined frequency. There is a phase difference between the phase transfer characteristics that decrease with frequency. For frequencies below a predetermined frequency, the amplitude transfer determined by the first transfer characteristic exceeds the amplitude transfer determined by the second transfer characteristic. By interconnecting the first input 2 and the second input 3, the amplitude transfer [(H1 + H2) * H3] between the mutually exclusive inputs and outputs becomes substantially constant.;Signal combining circuits are used in stereo audio reproduction systems to enhance stereo images, and the stereo audio reproduction systems form part of an audio-visual reproduction system, for example.