Patent ID: 8879747

Claim:
An audio system with at least one audio output channel comprising: a digital audio processor in which at least one digital filter is implemented for each of a plurality of audio channels; the digital filter of each of the audio channels comprises: an analysis filter bank configured to receive an input audio signal and divide the input audio signal into a plurality of sub-bands as sub-band signals having equal bandwidths, a spectra of the sub-band signals constituting a spectrum to of the input audio signal; a sub-band filter for each sub-band, the sub-band filter for each sub-band configured to provide respective filtered sub-band signals; and a synthesis filter bank configured to receive and combine the filtered sub-band signals to provide a broad-band output audio signal; where a delay is associated with each of the respective sub-band signals, the delay of one of the sub-band signals being applied to the input audio signal before division by the analysis filter bank, and residual delays being applied to at least some of the sub-band signals divided by the analysis filter bank.