Spectral compensation filters for close proximity sound sources

A method of generating a signal for driving a first linear array of multiple coherent sound sources, wherein said first linear array of multiple coherent sound sources comprises a primary sound source and one or more secondary sound sources, the method comprising the steps of:

• receiving an audio signal for a first channel of an audio system;
• deriving, from the audio signal, a first drive signal for driving the primary sound source and a second drive signal for driving the one or more secondary sound sources;
• applying a low-pass filter to the second drive signal for driving the one or more secondary sound sources, the low-pass filter reducing energy at higher frequencies where destructive interference would otherwise occur between sound from the primary sound source and the one or more secondary sound sources;
• and
• applying a corresponding high-frequency shelving filter to the first drive signal for driving the primary sound source, the high-frequency shelving filter compensating for reduction of energy at higher frequencies due to the low-pass filter, wherein a gain, g, of the high-frequency shelving filter is g=20 log10 (N+1), wherein Nis the number of secondary sound sources.