Loudspeaker and Headphone Design Approaches Enabled by Adaptive Nonlinear Control

Traditional loudspeaker and headphone design sacrifices efficiency for sound quality. Nonlinear, adaptive control can compensate for undesired signal distortions, protect the transducer against overload, stabilize the voice coil position, and cope with time-varying properties of the suspension. This paper discusses the consequences of new software opportunities for designing optimum hardware components that exploit available resources, such as a nonlinear voice coil gap configuration, a softer suspension, and modal vibrations in the diaphragm, panel, and in the acoustical systems to increase the efficiency of the electroacoustical conversion. Digital signal processing (DSP) software complementing transducer hardware is the key to modern audio devices generating the required sound output with minimum size, weight, cost, and energy.