A linear bar diffuser includes a grille frame and blades in a stacked arrangement within the grille frame such that space is provided between adjacent blades to facilitate flow of an incoming air flow therethrough. One of the blades includes a leading edge configured to face the incoming air flow, the leading edge including an undulated contour extending along a length of the blade and into a width of the blade, the width of the blade extending transverse to the length and between the leading edge and a trailing edge of the blade.