The paper presents experimental and numerical results for the Electromagnetic Particles Impact Damper (EPID). The damper consists of a container and freely moving metallic grains, which constitutes 30% of the total mass of the system. The damper is mounted on a cantilever beam subjected to resonant harmonic excitation. An electromagnet integrated into the damper enables real-time control of the amount of freely moving particles. Four distinct operating states are defined, corresponding to 100%, 66%, 33%, and 0% of the grains being allowed to move, depending on the applied electromagnetic field. While the volume of the cavity containing the granulate remains constant over time, several different container geometries are proposed. The dynamic structure of the system changes with each configuration, enabling dynamic mitigation of resonant vibrations. This feature is particularly critical in the case of sudden changes in excitation. Appropriate selection of the amount of freely moving granulate is essential for effective vibration suppression. The second part of the study focuses on the development of a theoretical model of the damper, which reduces the system to a multi-degree-of-freedom model with impacts modeled using the soft-contact theory. The proposed numerical model of the damper accurately reproduces the dynamic response observed in the experimental studies. For many years, researchers have investigated the Particles Impact Damper (PID) in terms of how its design parameters affect damping performance. Numerous constructions can be found in the literature, some of which allow for adaptive tuning of the damper’s volume. The innovative aspect of this paper lies in the proposal of a novel type of Impact Damper that allows for dynamic modification of the system’s structural dynamics by controlling the amount of freely moving granulate within the enclosure. This solution expands the control capabilities of PID technology, making it a promising candidate for widespread application in future engineering industries.