This paper deals with an active vibration protection (p-reduction) of the beam-actuators mechanical system, hence it concerns separate modes. The paper's aim is an eectiveness analysis of the p-reduction assuming dierent number of actuators. It is assumed a priori that actuators are bonded to the beam in the sub-domain with the largest curvatures and they are exactly the same. The beam clamped at one end is chosen as the research object. Next, as required by the p-reduction condition, the number and distribution of actuators are changed. It turns out that the best reduction eectiveness, measured via any eectiveness coecient, is obtained for one actuator bonded in the sub-domain with the largest curvature. The validation of theoretical considerations is conrmed numerically.