Amplitude Modulation Method for Measuring Linear Excursion of Loudspeakers

A simple method for measuring the peak linear excursion capability (Xmax) of loudspeaker drive units is presented. The method measures the acoustic amplitude modulation of a small high-frequency signal by a very low-frequency signal. The low-frequency signal is increased to produce a target peak-to-peak modulation. A physical measurement of the peak-to-peak diaphragm excursion is made and defined to be twice Xmax.