Abstract
Cone velocity of loudspeakers has been long recognized as an important parameter for loudspeaker compensation. In the paper, a cone velocity observer that requires no sensor is developed on the basis of state-space estimation. Linear quadratic Gaussian (LQG) theory in conjunction with multirate processing is employed in the design of the observer. The experimental results show close agreement between the velocities obtained by using the proposed technique and the measurement by a laser vibrometer. In addition, the system allows for self-identification and automated filter synthesis. The compensation filters are designed using the quantitative feedback technique (QFT) and implemented on a digital signal processor (DSP). The system is applied to two audio problems in loudspeaker compensation: bass enhancement and room response equalization. Experimental results are discussed.