Comparison between voltage and current driving methods of a micro-speaker

Since its inception, most audio amplifiers control the loudspeaker in voltage. However previous studies highlighted the importance of the loudspeaker control in current. These studies have been done only with large size loudspeakers (bass or midrange loudspeakers) and this is certainly not transposable for the type of loudspeaker in interest i.e. micro-speaker. First of all, this paper describes a model of loudspeaker (voltage driven and also current driven) represented by a comprehensive set of data based on a minimal number of measurements. Simulation results based on these models are presented using single frequency signals such as multi-frequencies signals to compare the two driven methods. At this level of modelling, simulation results show that, contrary to the woofer applications, current driving of micro-speaker does not affect significantly in terms of harmonic distortions, intermodulation distortions and transient behavior.