Pressure-matching beamforming method for loudspeaker arrays with frequency dependent selection of control points

The Pressure-Matching Method (PMM) is a signal processing technique used to generate the digital filters required by a loudspeaker array to reproduce a desired sound field. System performance depends on the choice of a number of parameters of the numerical algorithm, such as the target field and the regularization factor. If a target sound field is chosen with large amplitude variation between the so-called control points, performance might also depend on the relative distance between these points in relation to a the wavelength of the sound to be reproduced. If this distance is too small, the accuracy of the reproduced field may be reduced at the listener location. A strategy is proposed to improve the PMM that is based on a frequency-dependent selection of the control points that contribute to the PMM cost function. By means of numerical simulations and experiments in anechoic environment, it is shown that the proposed method allows for accurate control of the response of the reproduced field at the listener location