Comparison and verification of analogous circuit models for dynamic moving-coil transducers

For decades, analogous circuits have been used to model the electro-mechano-acoustical properties of moving-coil transducers. In recent years, many enhanced models have been proposed to improve the accuracy of their estimated voice-coil impedances. In this work, an iterative complex curve-fitting routine has been used to best fit and compare the various models to the measured complex input impedance data of several loudspeaker drivers in free air. The estimated blocked electrical impedance of each driver was extracted and used to predict its frequency-dependent cone velocity while under operation. Actual driver cone velocities were measured experimentally using a scanning laser Doppler vibrometer, and the predictions were compared to further substantiate the accuracy of each model. The results highlight those models with the greatest predictive capabilities and reliability.