Automatic correction of power spectral balance in audio source material

摘要

An audio system that automatically corrects for variations in spectral balance in audio source material. The audio system comprises a power spectrum analyzer and a source correction equalizer unit coupled to receive an audio input signal, and an index control unit coupled to a spectral balance correction data memory. A reference spectral balance may initially be established by playing a reference source medium with desired sound attributes. The power spectrum analyzer characterizes the spectral balance of the reference source medium, storing the results in non-volatile memory. When a particular source medium is played for the first time, the index control unit reads an identifying parameter from the particular source medium. Because there is no entry for the identifying parameter in spectral balance correction data memory, the particular source medium has not been previously played on the audio system. The particular source medium is then played in its entirety, with the index control unit signaling the power spectrum analyzer to characterize the spectral balance of the particular source medium. When the particular source medium is finished playing, an equalizer settings compute unit compares the reference spectral balance and the spectral balance for the particular source medium and calculates equalizer correction settings, which are then stored in spectral balance correction data memory. These settings can be used to adjust the spectral balance of the particular source medium to match that of the reference source medium. When the particular source medium is subsequently played, the identifying parameter may be used to recall these desired equalizer settings.