This paper presents the design and implementation of a closed-loop control scheme to regulate shock location within a Mach 1.8 wind tunnel isolator test section. As part of the feedback controller, the sensing scheme for shock localization utilizes a set of high frequency Kulite pressure transducers to sample the static pressure at various points along the wind tunnel test section. A geometry-based shock localization algorithm is then executed at 250 Hz to determine the location of the shock in real time. The closed-loop controller generates actuation commands for a motorized flap downstream of the test section every 100 ms toward regulating the shock at the desired position. Several forms of closed-loop implementation are addressed including: (a) simple logic-based controllers; (b) Proportional-Integral (PI) controllers, and (c) Proportional-Derivative (PD) controllers. In addition to using the geometry-based shock localization schemes, the paper also describes the implementation of a novel Kalman-filter-based framework for fusing estimates from other shock localization schemes such as standard deviation and sum-of-squares. It also explores important design criteria that should be considered for satisfactory control performance as a function of pressure transducer spacing, shock localization speed, flapmotor's actuation speed and actuator resolution. Experimental results are presented for various test scenarios such as regulation of the shock location in the presence of stagnation pressure disturbances as well as tracking of a time-varying reference input. Performance and robustness analysis of the control system during these tests is discussed. Further areas of improvement for the closed-loop control system in both hardware and software are discussed along with possible applications. Nomenclature DTR= Dense Transducer Region PD = Proportional-Derivative