Audio signal processing circuit

摘要

An audio signal processing circuit (12) for an audio reproduction apparatus which is designed to be of simple structure and of high accuracy. The processing circuit is of shuffler type and comprises a first filter (12SUM) for producing a sum signal of left and right channel signals, together with the second filter (12DIF) for producing a differential signal between the left and right channel signals. The accuracy of each second filter is chosen higher than that of the first filter in the low frequency region of the processing band. To this end the first filter and the second filter can be FIR filters, with the tap number of the second filter being larger than that of the first filter. In an alternative arrangement the first filter is an FIR filter while the second filter is composed of a parallel combination of an FIR filter and a secondary IIR filter.