We propose a system for rectification of acoustic waves. The system consists of an array of triangular holes drilled in an elastically isotropic material. Assuming the propagation of transverse acoustic waves with polarization parallel to the holes, we confirm numerically that the rectification of acoustic waves occurs even in the frequency region with corresponding wavelength comparable to the dimensions of the scatterers. The rectification effects appear above a threshold frequency due to the Bragg diffraction owing to the periodic structures. The threshold frequency depends on the structural parameters, which enables the realization of a tunable rectifier.