1. A method for adapting sound pressure levels in at least one listening location, the sound pressure being generated by first and second loudspeakers, each loudspeaker having a supply channel arranged upstream thereto, where at least the supply channel of the second loudspeaker modifies the phase of an audio signal transmitted therethrough according to a phase function, the method comprising: supplying an audio signal to the supply channels and generating an acoustic sound signal; measuring the acoustic sound signal at the listening locations and for each listening location providing corresponding electrical signals representing the measured acoustic sound signal; estimating updated transfer characteristics for each pair of loudspeaker and listening location based upon the measured acoustic sound signals; calculating an optimum offset phase value based on a mathematical model using the estimated transfer characteristics, wherein the optimum offset phase function is achieved when a resulting frequency response of the sound pressure levels at the listening location matches a predetermined target function; and updating the phase function by superposing the optimal offset phase function thereto.