A test apparatus is provided. The test apparatus includes a fluid release mechanism having a nozzle. The test apparatus furthers include a pressure plate coupled to a pressure sensor and a grille mounting plate disposed between the nozzle and the pressure plate. The grille mounting plate is disposed at a first distance from the pressure plate and a second distance from the nozzle. When activated, the fluid release mechanism releases a cleaning fluid at a first pressure through the nozzle and towards a first speaker grille mounted on the grille mounting plate. The first speaker grille includes a first hole pattern which diffuses the released cleaning fluid, causing the diffused cleaning fluid to strike the pressure plate at a second pressure. The pressure sensor records the second pressure when the diffused cleaning fluid strikes the pressure plate.