All electromechanical systems are prone to nonlinear distortions. Small loudspeakers and full-range loudspeakers are especially sensitive in this respect, since they have to perform long excursions due to the dynamic range. These types of distortions have been normally observed with methods that were developed for identification and quantification of individual types of nonlinear distortions. Most of them use well known test signals and extensive digital processing, usually switching from time domain into frequency domain and vice versa. In only few cases have nonlinear distortions been studied where they incorporated the nonlinear convolution operator into the convolution integral. The main objective of this work is to identify nonlinear operator of electromechanical system in the convolution integral for the purpose of simulating the nonlinear response. A comparison, between nonlinear response of electromechanical system with simulation, using convolution with incorporated nonlinear operator, is introduced in this work. To make this system applicative, all tests were performed on three different loudspeakers, because they are prone to nonlinear distortions. We developed a new test signal forcing the operation of the loudspeaker into nonlinear regime, which enables fast and lucid identification of nonlinear distortions.