The variation of the system parameters as a function of the voltage value sent to the speaker terminal for the first configuration: h_m1 = 0.23 mm, R_m1 = 5 cm, f_m1 = 45 Hz. The blue squares correspond to the result given by the HBM and the green triangles by the CX-A method. The beginning and the end of the energy pumping are presented by the two grey bands. (a) F as a function of the excitation amplitude. (b) ω_t as a function of the excitation amplitude. (c) λ as a function of the excitation amplitude. (d) c_η as a function of the excitation amplitude. (e) k_l as a function of the excitation amplitude. (f) k_nl as a function of the excitation amplitude. (g) β as a function of the excitation amplitude. (h) γ as a function of the excitation amplitude.