Active mounts allow you to tune out specific frequencies or adapt the damping characteristics of the mount depending on the driving mode or conditions.
A good example of this is a switchable hydramount. This technology has been critical in overcoming buyer perceptions that diesel engines are noisy and shaky. One of the major problems manufacturers face with diesel engines is that on ignition vibration and noise is greater than when the engine has warmed up.
With a switchable mount the stiffness and damping properties can be adapted using an actuator according to the engine load. So for example the hydraulic damping characteristics of a mount can be switched off when an engine runs in idle to achieve optimum noise isolation. Whilst when the engine moves into drive, the damping can be switched on to improve engine shake performance. For more information contact 