Abstract: Direct current (DC) offset has undesirable influence on loudspeaker performance. The relationships of the main nonlinear characteristics of loudspeaker, such as force factor, stiffness coefficient and inductance, with the DC components in the corresponding driving force, recovery force and magnetic resistance are studied. Then the DC components of voice coil displacement caused by the DC components of these forces are analyzed. A loudspeaker DC offset estimation method based on lumped parameter model (LPM) is proposed. Firstly, the nonlinear parameters such as Bl(x), K (x) and L (x) of loudspeaker are obtained based on numerical simulation analyses or measurements, and then they are substituted into the LPM model. The displacement response is calculated by solving the model, and the DC offset is obtained by further post-processing. By using this method, the DC offsets of a 6.5 in (1 in=2.54 cm) automobile loudspeaker and a 2 in full range loudspeaker are estimated, and the influences of various nonlinear parameters on the DC offset are analyzed. The measurement results of speaker DC offset show that the trends of the estimated curves are basically consistent with the measured curves. By properly adjusting the nonlinear parameters, the DC offset can be adjusted or reduced, thus optimize the design of high-quality speakers.