The integration of head-tracking can improve the achievable performance of active noise control headrest systems by allowing the mismatch between the plant model used by the controller and the physical plant response to be reduced. Although previous studies have shown that the performance improvement achieved through head-tracking is limited by the resolution of the tracking system, this limitation can be addressed by either interpolating between plant models obtained at different head positions and then calculating the required controller, or interpolating between a set of pre-computed optimal controllers obtained for different head positions. The differences in performance between the two interpolation strategies, however, have not been explored, despite various interpolation strategies being previously utilised in head-tracked active control systems discussed in the literature. This paper presents a comparison between the two approaches to spatial interpolation for a head-tracked active headrest system. Assuming a tonal disturbance, it is shown through numerical simulations that the performance benefit brought by spatial interpolation differs between the two approaches to interpolation. .