Nonlinear Adaptive Controller for Loudspeakers with Current Sensor

Nonlinear loudspeaker distortions are predictable and can be compensated by inverse preprocessing of the electric input signal. Control schemes developed so far require an acoustic or mechanic output signal measured at the speaker. An additional sensor increases the costs and is impractical under harsh environment. However, a motional signal can also be derivedfrom the back-induced EMF by monitoring the input current of the transducer only. Following this approach a novel nonlinear adaptive detector system is presented providing a robust and cost-effective DSP solution.