Variable control of the pre-response error in mixed phase audio precompensation

Abstract

We introduce a method for controlling the spatial robustness of a mixed phase loudspeaker equalizer design. The emphasis is on time domain behaviour and the pre-response error that is always present in mixed phase design. Based on measurements from a small spatial region, a mixed phase compensator is regularized to be valid also over a large spatial region. The regularization can be applied gradually to match any size of listener region, while fulfilling a set of constraints for the pre-response error. The compensation thus avoids the unacceptably high pre-response error levels that generally occur outside the measurement region. The proposed compensator design, which is validated on measurements in both small and large spatial regions, is shown to produce excellent results.