Audio precompensation controller design with pairwise loudspeaker channel similarity

A system for determining an audio precompensation controller for an associated sound generating system comprising a total of N≧2 loudspeakers, each of said loudspeakers having a loudspeaker input, said audio precompensation controller having a number L≧2 inputs for L input signals 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, wherein said system comprises:

• 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 signals, a selected one of said N loudspeakers as a primary loudspeaker;
• means for specifying, for each of the L input signals, a loudspeaker pair, if feasible, where said loudspeaker pair is required to be symmetric, or similar, with respect to the listening position;
• means for specifying, for each primary loudspeaker, a target impulse response at each of said M measurement positions;
• and
• means for determining, for each one of said L input signals, based on the selected primary loudspeaker and the selected loudspeaker pair, 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, or a subset of said M, measurement positions, and a weighted and permuted summation of powers of differences between at least one pair of equalized symmetrical room transfer functions.

A computer program product encoded on a non-transitory computer-readable recording medium that, upon execution by a processor device of a computer system, causes the computer system to operate as an audio precompensation controller for an associated sound generating system including a total of N≧2 loudspeakers, each of said loudspeakers having a loudspeaker input, said audio precompensation controller having a number L 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, wherein said computer program configured to cause the computer system to perform the functions of:

• estimating, for each one of at least a subset of said N loudspeaker inputs, an impulse response at measurement position(s) in a listening environment, based on sound measurements at said measurement positions;
• specifying at least one loudspeaker pair, where said loudspeaker pair is required to be symmetric, or similar, with respect to the listener position;
• and
• determining, for each one of said L input signals, based on the selected loudspeaker pair, 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 and permuted summation of powers of differences between at least one pair of equalized symmetrical room transfer functions.