In the paper the method of creating the dynamical model of the mechanical system is considered. The transient process measured after the hammer blow is used as input data. Prony method with its improvements is used for the estimation of unknown parameters of the model. Using the FFT and IFFT procedures the sample data is decomposed into two parts: a high frequency component and a low frequency component. Each part is investigated separately. While the high frequency component was modeled by using a simple six poles model, the low frequency component was modeled by a single multiple pole. The correctness of the model was checked by RMSE criteria. The RMSE of the low frequency component model versus the multiplicity of the pole was investigated. The results show good agreement with experimental data. The full final model was used to get the amplitude-frequency response of the system.