1. A method for determining an inverse filter for a loudspeaker having an impulse response, including the steps of: measuring the impulse response of the loudspeaker at each of a number of different locations relative to the loudspeaker; time-aligning and averaging the measured impulse responses to determine an averaged impulse response; and determining the inverse filter from the averaged impulse response and a target frequency response, including by applying critical frequency band smoothing, wherein the step of determining the inverse filter includes a step of normalizing the inverse filter against a reference signal, and said normalizing the inverse filter adjusts overall gain of the inverse filter so that perceived loudness of audio determined by the inverse filter applied to the averaged impulse response applied to the reference signal does not shift relative to perceived loudness of audio determined by the averaged impulse response applied to the reference signal.