PURPOSE: To improve the sound qualities of main and sub-sound, by demodulating the sub-sound signal at a demodulation circuit of the split carrier system, and the main sound signal at the demodulation circuit of the intercarrier system.

CONSTITUTION: A main sound signal is obtained from a sound demodulation circuit of the intercarrier system comprising a filter 4, an amplifier 5, a sound signal detection circuit 6, a frequency discrimination circuit 7, and an LPF 8, and sub-sound signal is obtained from a sound demodulation circuit of the split carrier system comprising a filter 12, an amplifier 13, a mixing circuit 14, a local oscillation circuit 15, a ceramics filter 16 and a frequency discriminating circuit 17, via a BPF 18, a limiter circuit 19, and a frequency discriminating circuit 20. Both the signals are applied to a matrix circuit 9, the output is switched into a monaural broadcast or a multiplex broadcast program at a switching circuit 10, and a stereo program and a sound multiplex program at the multiplex broadcast are picked up through switching at a switching circuit 11.