This paper presents the modal control applied to motion systems, in particular for machine tools. This control approach is particularly suitable for over-actuated systems that have more actuators than degrees of freedom. By using the modal approach, the parameterisation of the control loops is simplified since each control loop corresponds to a specific eigenmode. A four-variable modal control of a linear motor-driven gantry system equipped with additional active damping devices is presented to achieve active vibration suppression. This approach is experimentally compared with a conventional control method that does not consider the eigenmodes of the system. The influence of the vibration controllers on the closed position loops is investigated.