PROBLEM TO BE SOLVED: To provide an audio signal processing apparatus capable of rightly localizing a sound image in a case where a satellite speaker is small-sized. SOLUTION: From small-sized satellite speakers 3L and 3R, middle- and high-pitched sounds of strong directivity are outputted and for an audio signal S4 of a middle or low range having a certain degree of directivity, the correlation to the relevant middle- and high-pitched sounds is reduced by a correlation reduction filter 16 and further delayed a little rather than the relevant middle- or high-pitched sounds by a delay circuit 17, so that a middle- or low-pitched sound in which a frequency component is maintained and the contribution to a sound image is reduced, can be outputted from a sub woofer 4. Thus, the sound image formed from the middle- and high-pitched sounds from satellite speakers 3L and 3R is not disturbed by the middle- and low-pitched sound outputed from the sub woofer 4, so that a degree of freedom in the install place of satellite speaker can be improved, the sound image is rightly localized and a listener 100 can listen to sounds of excellent frequency characteristics. COPYRIGHT: (C)2008,JPO&INPIT