<p>Seismic waves are vibrations that propagate through a soil mass due to an external mechanical pulse. Depending on wave velocity and wave type, a mechanical evaluation can be obtained for a soil mass. Subsequently, certain devices and techniques are required to produce and detect seismic waves. Although commercial devices exist for this task, they are expensive, and few institutions have access to them. This study aims to evaluate the effect of water on P- and S-wave velocities in unsaturated compacted granular soil specimens, using a proposed experimental setup for each wave type and low-cost piezoelectric sensors. Unlike the conventional Bender element procedure, seismic vibrations were generated externally by gently striking the upper cap of the specimen. The sensor signals were improved using a low-pass filter to eliminate noise. Additionally, the vapor transfer technique was used to control moisture in the specimens, thereby achieving various degrees of saturation for each specimen subjected to seismic testing. Results indicate that, in the unsaturated condition, as the saturation in the specimen increases, the P-wave velocity tends to decrease. However, this behavior is not clearly defined in S-wave velocity measurements, where the data showed significant dispersion. Although a poor pattern was observed, it is possible to conclude that S-wave velocity is not closely related to the degree of saturation.</p>