1. Shanghai Acoustics Lab, Institute of Acoustics, Chinese Academic of Sciences, Shanghai 200032，China；2. Jiaxing Engineering Center, Institute of Acoustics, Chinese Academic of Sciences, Zhejiang, 314006， China
Abstract：Volterra model is often applied in analyzing nonlinear vibration of loudspeaker diaphragm. However, with higher input voltage, the error of frequency response has the trend of becoming larger. Therefore, the model is limited to the analysis of systems with weak nonlinearity. Due to the problem, an improved model is proposed. In order to provide a more accurate result, the displacement of rest position of diaphragm was adopted to modify the nonlinear parameters, and the high-order intermodulation terms were evolved in calculating displacement response. A laser measurement system which can be used for measuring instant displacement of diaphragm was built. In the experiment, the displacement of rest position and linear response of displacement were recorded and calculated. The result of improved Volterra model showed a better agreement comparing with the conventional model.
2012, Vol. 31 
