Apparatus demodulates frequency-modulated information signals on a radio frequency signal carrying on a suppressed superaudio carrier signal, amplitude-modulated spectral components in a subcarrier channel frequency range above the audio frequency range and frequency modulated spectral components within the audio range. A demodulator demodulates the frequency-modulated information signals to provide detected audio signals having spectral components within the audio frequency range and detected superaudio signals having spectral components including those within the subcarrier channel frequency range above the audio frequency range in response to modulated radiated radio frequency signals arriving at the apparatus over a number of paths of different lengths. There is a reference signal source responsive to the detected superaudio signals that provides a reference signal of the frequency of the suppressed subcarrier characterized by a phase shift substantially the same as that imparted to the detected spectral components within the subcarrier channel frequency range. The reference signal is combined with the detected spectral components within the subcarrier channel frequency range to provide an audio signal.