An experimental study was conducted to investigate the pressure fluctuations on the entire side wall of a rectangular cavity with an L/D of 5.67 using fast-response pressure sensitive paint. Additionally, the performance of four different passive flow-control devices was quantified. Experiments were conducted in the Trisonic Gasdynamics Facility at the Air Force Research Laboratory at Mach 0.7 and 1.5. The frequency spectrum (including Rossiter tones) and sound pressure levels (SPLs) obtained from the pressure sensitive paint (PSP) measurements are validated against data taken with conventional dynamic pressure sensors. The complex flow phenomena over the cavity wall were visualized, and full wall pressure spectra were calculated. The rod in cross flow showed the best peak suppression, followed closely by the flat spoiler. The large triangular step showed some peak suppression, while the ridges did not suppress the peaks at all. High resolution measurements of pressure fluctuations on the wall allowed for the visualization of SPL distribution over the entire cavity wall. This revealed a strong dependence between the Rossiter tone modes and the spatial distribution of SPL that was not possible to resolve with discrete pressure transducers.