An impact crusher for crushing a feed material received through an opening of the crusher is provided. The crusher includes: a housing defining a crushing chamber; at least one elevation adjustable impact barrier mounted in the crushing chamber; a barrier adjustment mechanism configured to adjust an elevation of the at least one impact barrier within the crushing chamber; and a rotor mounted in the crushing chamber and turned by a drive mechanism. The rotor is configured to direct feed material toward the at least one impact barrier. The bather adjustment mechanism includes at least one hydraulic cylinder mounted to the at least one impact barrier. The cylinder includes a sensor for detecting an absolute extension of the cylinder. A system for crushing a crushable material including an impact crusher and controller is also provided herein.