Many real-world systems exhibit nonlinear behavior that must be taken into account when modeling such systems. In practise, especially in the field of electro-acoustics, nonlinearities appear with increasing input level. These nonlinearities are usually modeled by adding nonlinear parameters to the linear model, but the determination of nonlinear physical parameters is rather difficult problem. The authors present a simple method for analysis and identification of nonlinear systems, based on swept-sine signal excitation. The method is based on nonlinear convolution, firstly proposed by Angelo Farina [1], which serves for analysis of nonlinear amplitude characteristics. The result of the nonlinear convolution method is the set of harmonic distortion products (higher order nonlinear impulse responses) that can be expressed either in the form of the separated impulse responses or in the form of frequency dependent components. The original method [1] was improved in order to analyze also the phase characteristics of all the nonlinear parts. Therefore, the excitation sweep signal from the improved method [2] has to be setup very properly. The precisely measured nonlinear amplitude and phase characteristics can be used for analysis of the nonlinear system under test, or for identification of a nonlinear model (i.e. generalized Hammerstein model). The method is presented here when studying an electrodynamic loudspeaker from the nonlinear point of view. More precisely the electrodynamic loudspeaker under test is characterized by its electrical impedance leading to Thiele/Small parameters in a nonlinear framework. [1] A. Farina, "Simultaneous measurement of impulse response and distortion with a swept-sine technique", in Proc. 108th AES Convention, Paris, February, 2000. [2] A. Novak et al., "Nonlinear System Identification Using Exponential Swept Sine Signal", accepted for publication in IEEE Instrumentation and Measurement, 2009