An active vibration control system using an inertial actuator for suppression of multiple unknown and/or time-varying vibrations will be presented. The objective is to minimize the residual force by applying an appropriate control effort through the inertial actuator. The system does not use any additional transducer for getting in real-time information upon the disturbances. A direct feedback adaptive regulation scheme for the suppression of multiple unknown and/or time-varying vibrations will be used and evaluated in real time. It uses the internal model principle and the Youla-Kucera parametrization. In the Appendix, a comparison with an alternative indirect adaptive regulation scheme is presented.