Self-Adjusting Audio Equalizer, A

One goal of an audio equalizer is to adjust an audio signal to compensate for the acoustics of the speakers playing the signal as well as the room in which the signal is played. Certain frequency bands are amplified while others are attenuated, so that any damping of the sound in the room is 'equalized' and, ideally, the frequency response of the audio system in combination with the room is flat. The system achieves this by measuring the power of a calibration tone in each frequency band and comparing to it a measurement taken by a microphone. It then adjusts each band accordingly in an effort to produce a flat frequency response, saving and reporting the settings to the user.