Personal sound zones (PSZ) allow several people sharing the same room to listen to different audio content without using headphones. Loudspeaker arrays with filtered inputs are typically used to create the PSZ. The driving filters are calculated from the transfer functions between each loudspeaker and the points sampling each listening zone. These filters are usually computed once and are no longer relevant if the loudspeakers are driven at higher levels, especially for low-cost drivers which can exhibit a strong non-linear behavior. In this paper, a state space model is used to predict the nonlinear behavior of loudspeakers. Nonlinear parameters (force factor, stiffness and inductance) as a function of the diaphragm displacement are measured for each 2" Tectonic loudspeaker using a Klippel R&D system. Then, the accuracy of the state space model is checked by comparing the predicted harmonic distortion to the measured one for several input levels. Finally, the state-space representation is used to predict the effect of non-linearities on PSZ metrics. Simulation results show that the contrast can be reduced by about 10 dB and the error can increase by a factor of about 1000 in the low frequency range when large input signals are required.