Time-domain measurement of loudspeaker driver parameters

A new method for the measurement of the Thiele-Small small-signal parameters of a moving-coil electromagnetic transducer driver is described. The technique is based on a time-domain analysis of the transient response of the loudspeaker voice-coil circuit to a current step of excitation. By sampling the damped sinusoidal transient generated by such an excitation, the loudspeaker parameters can be calculated from a linear predictive analysis of the recorded data. The technique has been implemented with a digital computer and measurement examples are presented. The method is simple and can be implemented with a microprocessor configuration for rapid assembly line testing.