| 摘要 |
PROBLEM TO BE SOLVED: To improve the separation of a matrix circuit by sufficiently attenuating a sound sub signal in the signal path of a main signal (L+R). SOLUTION: A sound multiplex signal demodulating circuit is equipped with an LPF (8) which is applied with a sound main signal of an FM-demodulated base band and has a secondary or more cutoff property of passing a signal of frequency in the audible band, an FM demodulator (6) which demodulates an FM-modulated sound secondary signal, and a matrix circuit (10) which forms matrices with the sound main signal from the LPF and the sound secondary signal from the FM demodulator, thereby the LPF (8) can sufficiently attenuate the sound secondary signal in the sound main signal path.
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