Broadband Sound Absorption with Low-Perforation Micro-Perforated Panels Coupled with Space-Coiling and Helmholtz Resonators: Numerical and Experimental Study

This study proposes a new sound absorbing panel designed for broadband low-frequency performance. The panel integrates a fixed low perforation rate micro-perforated panels (MPPs) with space-coiling and Helmholtz resonator slit-type structures, forming single- and double-layer units capable of wideband absorption. A hybrid series–parallel configuration, investigated using finite element analysis (FEA), creates multiple resonance peaks and enhances absorption bandwidth across low, mid, and high frequencies. To get optimum efficiency, a genetic algorithm (GA) is employed to optimize key geometric parameters. Experimental tests are conducted on both unoptimized and optimized prototypes, each with a 41 mm air cavity. The unoptimized design provides an absorption bandwidth of 1250 Hz (350–1600 Hz), while the optimized panel extends this slightly to 1255 Hz (345–1600 Hz). The Impedance tube measurements were validated against numerical predictions and, with the optimum design having a bandwidth-to-thickness ratio of 30.60 and being excellent performance than current absorbers documented in the literature. The proposed sound absorbing panel is thin and lightweight, making it particularly suitable for applications where weight and space constraints are critical, such as aerospace, civil engineering, and transportation, while providing a compact and practically feasible solution for broadband passive noise control.