Compensating the distortion of micro-speakers in a closed box with consideration of nonlinear mechanical resistance.

For micro-speakers in a closed box, commonly used nonlinear compensation methods only compensate the distortion caused by the force factor and the stiffness. In this letter, a method to compensate the distortion with consideration of the nonlinear mechanical resistance is proposed based on the feedback linearization criterion. The proposed method is further improved by minimizing the variation of the output power spectrum after compensation. The simulations and experiments show that the total harmonic distortion and the intermodulation distortion of the sound pressure can be reduced significantly with little influence on the sound pressure level.