sensor for monitoring the rotational velocity of drum 108 or an accelerometer that monitors drum vibration the sensor is fixedly mounted on the housing drum 106 but may be fixed in any suitable location for example alternatively the accelerometer may be fixed to the housing 102 to measure the housing vibration during use when power is supplied continuously to the washing machine 100 a and the drum 108 is spinning with a rotational velocity or drum spin speed that is within a range of speeds predetermined to coincide with a resonance condition in the drum for example the range between points a and b in fig2 a damper activating signal in the form of a current is sent from the master controller 120 to the dampers 10 a in the manner represented schematically in fig3 a the resonance condition typically occurs during the machine spin cycle the current signal sent by controller 120 to the dampers changes the rheology of the field controllable material as the viscosity of the material is increased the dampers 10 a provide the damping required to absorb the vibratory loads present during the resonance condition at predetermined intervals the sensor 122 delivers signals indicating the measured rotational velocity of the drum 108 to the master controller 120 and the controller logic determines when the speed of the drum is outside the resonance spin speed limits when the speed is outside of the spin speed range defined between points a and b the controller stops sending the current signal to the dampers and the damping provided by dampers 10 a is reduced the apparatus 100 a also includes a first embodiment means for limiting vibration in the apparatus 100.