Increasing the efficiency of the electro-acoustical conversion is the key to modern audio devices generating the required sound output with minimum size, weight, cost and energy. There is unused potential for increasing the efficiency of the electro-dynamical transducer by using a nonlinear motor topology, a soft suspension and cultivating the modal resonances in the mechanical and acoustical system. However, transducers optimized for maximum efficiency are more prone to nonlinear and unstable behavior. Nonlinear adaptive control can compensate for the undesired signal distortion, protect the transducer against overload, stabilize the voice coil position and cope with time varying properties of the suspension. The paper discusses the design of modern active systems that combine the new opportunities provided by software algorithms with the optimization of the hardware components in the transducer and power amplifier.
展开▼
