Optimizing low-frequency performance within enclosed spaces is often achieved through solutions involving acoustic absorption, including Helmholtz resonators. This thesis specifically focuses on the design of a "damped" variant of these resonators, characterized by the absence of sound-absorbing material inside. The main objective is to experimentally explore and validate the differences between the effects of a real resonator and a theoretical one, also confirming a modal division phenomenon previously observed in simulations. Within the scope of this thesis, the methodology, both simulation-based and experimental, that guided the design and realization of the resonator is carefully discussed. In designing this resonator, it is crucial to identify the frequency to focus on to adjust the resonator's absorption.