On the effect of the grille on the acoustic frequency response of a tweeter loudspeaker

Loudspeaker grilles are placed in front of loudspeakers to protect the high-frequency producing transducers (tweeters). Because of their placement, they are an essential part of the visual design of the loudspeaker. These grilles often have a perforated structure to allow sound transmission and prevent direct contact with the loudspeaker. This study examined the effect of tweeter grilles on frequency response (sound quality). The grille’s thickness, type and size of the holes in the grille were chosen as study factors. In this study, to minimize the frequency response deviations, it was found that the grille thickness for loudspeakers in the frequency range of 3 kHz to 20 kHz should be as thin as possible, considering mechanical strength. The grille openness ratio should also be chosen as 50% or higher. At the same openness ratio, circular and shrinking holes result in the least frequency magnitude deviation, while radial-type grilles exhibit 3dB less deviation than grilles with homogeneously distributed holes.