Patent ID: 8290180

Claim:
A signal processing device, comprising: a bass signal extractor that extracts a low-frequency band signal from an input audio signal; a harmonic wave generator that generates a harmonic signal from the low-frequency band signal that was extracted by the bass signal extractor; a level detector that detects a level of the low-frequency band signal extracted by the bass signal extractor; an adjustment controller that controls an adjustment of both the level of the low-frequency band signal extracted by the bass signal extractor and the level of the harmonic signal generated by the harmonic wave generator, the adjustment being conducted according to the level of the low-frequency band signal detected by the level detector; and an adder that adds, to the input audio signal, the low-frequency band signal and the harmonic signal that were level-adjusted by the adjustment controller; and a first filter that applies set signal characteristics to combined signal components that result from the adder adding together the low-frequency band signal, the harmonic signal, and the input audio signal.