Abstract: A vibratory apparatus includes a surface having an input end and an output end, and a vibratory generator coupled to the surface to cause material to move along the surface. The apparatus also includes a barrier coupled to the surface and having a plurality of openings disposed therethrough to provide for controlled passage of materials from an upstream side of the barrier to a downstream side, and a solid gate disposed to one side of the barrier, the gate moveable relative to the barrier between a first position wherein a first portion of the plurality of openings are occluded and a second position wherein a second portion of the plurality of openings are occluded, the first portion being different than the second portion. A method of operating such an apparatus is also provided.