An adaptive three parameter isolator assembly, comprising: a three parameter isolator having opposing hydraulic chambers (44, 46) configured to be filled with a Magneto-Rheological damping fluid; an MR valve (34,100) external to the three parameter isolator and fluidly coupled between the opposing hydraulic chambers, the MR valve configured to generate a magnetic field through which the MR damping fluid passes when flowing between the opposing hydraulic chambers; and a control device operably coupled to the MR valve and configured to control the strength of the magnetic field to adjust the viscosity of the MR damping fluid during operation of the three parameter isolator; wherein the three parameter isolator comprises: a first mechanical input/output; a second mechanical input/output; a damper (44, 46, 48) containing the opposing hydraulic chambers and positioned within a first load path extending between the first mechanical input/output and the second mechanical input/output; and a main spring (52, 84) mechanically coupled in parallel with the damper, as taken along a second load path extending between the first mechanical input/output and the second mechanical input/output; and characterized in that the three parameter isolator has (i) a main spring constant (K A) primarily defined by the main spring, and (ii) a tuning spring constant (K B) at least partially defined by a volumetric stiffness of the damper when filled with the MR damping fluid. a three parameter isolator having opposing hydraulic chambers (44, 46) configured to be filled with a Magneto-Rheological damping fluid; an MR valve (34,100) external to the three parameter isolator and fluidly coupled between the opposing hydraulic chambers, the MR valve configured to generate a magnetic field through which the MR damping fluid passes when flowing between the opposing hydraulic chambers; and a control device operably coupled to the MR valve and configured to control the strength of the magnetic field to adjust the viscosity of the MR damping fluid during operation of the three parameter isolator; wherein the three parameter isolator comprises: a first mechanical input/output; a second mechanical input/output; a damper (44, 46, 48) containing the opposing hydraulic chambers and positioned within a first load path extending between the first mechanical input/output and the second mechanical input/output; and a main spring (52, 84) mechanically coupled in parallel with the damper, as taken along a second load path extending between the first mechanical input/output and the second mechanical input/output; and a first mechanical input/output; a second mechanical input/output; a damper (44, 46, 48) containing the opposing hydraulic chambers and positioned within a first load path extending between the first mechanical input/output and the second mechanical input/output; and a main spring (52, 84) mechanically coupled in parallel with the damper, as taken along a second load path extending between the first mechanical input/output and the second mechanical input/output; and characterized in that the three parameter isolator has (i) a main spring constant (K A) primarily defined by the main spring, and (ii) a tuning spring constant (K B) at least partially defined by a volumetric stiffness of the damper when filled with the MR damping fluid.