In a mixer system including: a plurality of mixer engines each provided with a programmable DSP; and a PC controlling operations of the respective mixer engines, the PC stores, as zone data, a plurality of configuration data each indicating a configuration of signal processing to be executed by one mixer engine or more out of the mixer engines under the control of the PC, accepts the selection of the zone data, and when the necessary mixer engines are in a controllable state, transfers data on a part of the aforesaid configuration which is to be assigned to each of the mixer engines, to the corresponding mixer engines. Then, when the selection of the configuration is accepted, each of the mixer engines to which the configuration is transferred is caused to execute the audio signal processing according to the selected configuration.