This paper proposes new methods which improve the robustness and the performance of the passive vibration suppression by a dual electrical absorber using piezoelectric elements and analog circuits. Two types of methods which use two inductances were proposed in this paper. Because the electrical systems of new methods have two resonance frequencies, those new methods could improve the performance and the robustness by choosing the inductances and resistances of the circuit. Optimum values of the circuit were derived for both cases with and without the variation of the stiffness of the main system. The effectiveness of new methods and the optimum values of the circuit were verified by calculation and experiment.