Abstract: An isolation system includes a platform, a plurality of isolators for the platform electronically switchable between a soft mode of isolation resulting in a first natural frequency and a stiff mode of isolation resulting in a second natural frequency, and a controller responsive to a signal representing the frequency of a machine on the platform and configured to switch the isolator to the stiff mode of operation when the frequency of the machine approaches or reaches, the first natural frequency to avoid resonance magnification, and otherwise switch the isolation to the soft mode of operation.