Audio Precompensation Controller Design Using a Variable Set of Support Loudspeakers

A system for determining an audio precompensation controller for an associated sound generating system comprising a total of N>2 loudspeakers, each having a loudspeaker input, said audio precompensation controller having a number L>1 inputs for L input signal(s) and N outputs for N controller output signals, one to each loudspeaker of said sound generating system, said audio precompensation controller having a number of adjustable filter parameters, with said system comprising:

• means for estimating, for each one of at least a subset of said N loudspeaker inputs, an impulse response at each of a plurality M>2 of measurement positions, distributed in a region of interest in a listening environment, based on sound measurements at said M measurement positions;
• means for specifying, for each one of said L input signal(s), a selected one of said N loudspeakers as a primary loudspeaker and a selected subset S including at least one of said N loudspeakers as support loudspeaker(s), where said primary loudspeaker is not part of said subset;
• means for specifying, for each primary loudspeaker, a target impulse response at each of said M measurement positions with said target impulse response having an acoustic propagation delay, where said acoustic propagation delay is determined based on the distance from the primary loudspeaker to the respective measurement position;
• and
• means for determining, for each one of said L input signal(s), based on the selected primary loudspeaker and the selected support loudspeaker(s), filter parameters of said audio precompensation controller so that a criterion function is optimized under the constraint of stability of the dynamics of said audio precompensation controller, with said criterion function including a weighted summation of powers of differences between the compensated estimated impulse responses and the target impulse responses over said M measurement positions.

A computer program product for determining, when running on a computer system, an audio precompensation controller for an associated sound generating system comprising a total of N>2 loudspeakers, each having a loudspeaker input, said audio precompensation controller having a number L>1 inputs for L input signal(s) and N outputs for N controller output signals, one to each loudspeaker of said sound generating system, said audio precompensation controller having a number of adjustable filter parameters, with said computer program product comprising:

• program means for estimating, for each one of at least a subset of said N loudspeaker inputs, an impulse response at each of a plurality M>2 of measurement positions, distributed in a region of interest in a listening environment, based on sound measurements at said M measurement positions;
• program means for specifying, for each one of said L input signal(s), a selected one of said N loudspeakers as a primary loudspeaker and a selected subset S including at least one of said N loudspeakers as support loudspeaker(s), where said primary loudspeaker is not part of said subset;
• program means for specifying, for each primary loudspeaker, a target impulse response at each of said M measurement positions with said target impulse response having an acoustic propagation delay, where said acoustic propagation delay is determined based on the distance from the primary loudspeaker to the respective measurement position;
• program means for determining, for each one of said L input signal(s), based on the selected primary loudspeaker and the selected support loudspeaker(s), filter parameters of said audio precompensation controller so that a criterion function is optimized under the constraint of stability of the dynamics of said audio precompensation controller, with said criterion function including a weighted summation of powers of differences between the compensated estimated impulse responses and the target impulse responses over said M measurement positions.