An experimental implementation of a rapid active control strategy for flexible structures combined with a modal filter for state reconstruction is presented. The control law, which builds upon Komornik's original idea, is designed so as to achieve an arbitrarily large decay rate of the energy of the system, at the price of solving once and for all a well-conditioned small-size linear system, instead of a Riccati equation. It is applied to a slender beam. The fundamental ideas and properties of this simple but efficient strategy are explained. The emphasis is put on the practical implementation and on the experimental results, which show an important increase of the apparent modal damping even for values of the resulting gain that do not generate spill-over. The proposed feedback outperforms the standard LQ control. The actual behaviour of the closed-loop system is accurately predicted by a complete electro-mechanical model that accounts for the identified dynamics of the shaker.