Fused Deposition Modeling (FDM), an extrusion-based additive manufacturing (AM) technique, enables the fabrication of complex lattice structures with tailored mechanical properties. Despite its widespread use and technological advancements, the layer-by-layer deposition process introduces unavoidable geometric imperfections, which can significantly influence the mechanical behavior of the printed components [1]. Besides, a comprehensive overview of the impact of such imperfections on the properties of lattice metamaterials is still lacking. Among the various applications of AM designed structures, wave filtering and vibration control are of particular interest and can be tuned through the microstructural geometry of the metamaterials. This work investigates the dynamic response of 3D printed lattice structures made of thermoplastic polyurethane (TPU) [2], focusing on their ability to control vibrations and filter waves. The study explores how these features are affected by the presence of manufacturing-induced geometric imperfections [3]. A combined numerical–experimental approach is employed [4] to assess how FDM specific defects, such as node positions irregularities, section variations and axis offsets, affect dispersion relations and energy transmissibility. Digital Image Correlation techniques are also employed to capture the real geometry of the specimens. Preliminary results show that these deviations can induce local resonance effects and shift bandgap frequencies, ultimately altering the wave-filtering capabilities of the metamaterial. This research is aimed at understanding how these deviations from the original configuration affect the mechanical response of the specimens and how these can be modeled and possibly exploited. The ultimate goal is to move beyond the conventional idea of perfect configurations, to open possibilities for innovative applications in engineering and materials science.