A self-correcting audio equalizer is disclosed for use in a high fidelity sound reproduction system. The equalizer (46) responds to the audio signal to provide an equalized audio signal to a sound reproducing device (28) for generating a corresponding acoustic signal. The equalizer includes circuitry (48- 58) for dynamically measuring the differences between the frequency versus amplitude characteristics of the audio and acoustic signals. Another circuit (60- 68) automatically adjusts the frequency versus amplitude characteristics of the equalized audio signal so that the measured differences are reduced. The adjustment of the equalizer thus takes place automatically and substantially continuously during normal operation of the system.