Flexible couplings together with resonance phenomenon are present mainly in the field of servodrives where high accuracy and dynamic requirements are crucial. When dynamics doesn’t correlate with mechanical system design, unwanted frequencies in the system are exited. Sometimes we haven’t conditions (whether material or space) to design mechanical system with resonant frequencies too high to be exited. In that case we must choose compensating methods which can eliminate these phenomenons. This paper is dedicated to them.