Method and, apparatus for implementing the method, the method comprising determining control signal data for an array of loudspeakers, the control signal data being such as to control the loudspeakers to produce a desired sound field associated with an audio signal, the method comprises determining control signal data for different frequency components of the desired sound field in respect of respective different positions in a listening volume of the loudspeaker array, wherein determination of the control signal data comprises sampling the desired sound field at the surface of a control volume (V).