Application of radiation mode in desired sound field generation using loudspeaker array

The paper presents two preprocessing methods for the task of generating a desired response in a target region while simultaneously depressing the sound pressure level (SPL) in a stop region using a loudspeaker array. The first is a least squares method applying a commonly used cost function. The complex source strengths/weights are obtained by optimizing the cost function. The least squares solution may cause a low gain problem. The problem can be solved by the second method, which incorporates a radiation mode filter in the cost function. Simulations show that the second method offers the flexibility of controlling the gain of the array and still maintains the fidelity of generating the desired sound field.