A vibrating screen separator comprising a tuned suspension system for controlling a sifting screen and a resiliently isolated vibrator drive system for efficiently vibrating the screen cloth. The separator may be configured with stacked decks and serially connected sections involving multiple cooperating sifting planes. A rigid frame inclined above a supportive surface suspends the cloth for sifting material. The cloth is tensioned between frame sides by mounting rails, and it overlies a reinforcing subframe. The rails are tensioned by eye nuts externally accessible at the sides of the frame. Material gravitationally flows over the vibrating screen towards the discharge end. The cloth is shaken by an elongated, center strip aligned with the direction of material travel. The center strip is oscillated by the vibrator drive system disposed above it, which is coupled thereto by linkage. The tuned suspension system comprises a pair of generally cylindrical, rubber buffers mounted in shear that connect each end of the center strip to the subframe. Thus the center strip ends are resiliently isolated relative to the subframe. Through this arrangement vibrations are uniformly distributed throughout the surface area of the cloth. The vibrator drive system comprises a rotary, electric vibrator mounted in shear by sets of rubber buffers. The axis of rotation of the motor is aligned with the direction of material travel.