A method and apparatus in a sound-reproduction system, in which method an electrical calibration signal is formed, an audio signal is formed in the loudspeaker from the calibration signal, the response of the audio signal is measured and analysed, and the loudspeaker system is adjusted on the basis of the measurement results. The operator is permitted to made additional alterations to the settings of the loudspeaker system on the basis of the measurement performed, the effects of the alterations are calculated and displayed to the operator without additional measurements, and the additional settings are implemented in real time in the loudspeaker system.