How does perforation size impact the sound absorption of mesh panels?

Perforation size directly affects the sound absorption characteristics of aluminum mesh panels by altering the acoustic impedance and airflow through the panel. Larger perforations (2.5–4 mm diameter) with open-area ratios above 20 % facilitate greater air movement into the backing cavity, improving mid-to-high-frequency absorption (1,000–4,000 Hz). Conversely, micro-perforations (0.5–1.0 mm) with lower open area (< 10 %) offer better low-frequency attenuation when paired with deeper air cavities (≥ 100 mm) and dense backing materials. The ideal perforation diameter and open-area ratio depend on targeted frequency ranges and desired NRC ratings. For a broad-spectrum NRC of 0.6–0.8, specify 2 mm perforations at 15–25 % open area with a 50–75 mm cavity filled with mineral wool. To enhance bass response, increase cavity depth and reduce perforation size to focus on lower Hz. The backing material’s flow resistivity and the cavity depth are equally critical; without adequate backing, even optimally perforated panels underperform. By tuning perforation parameters and backing configuration, designers can achieve precise acoustic goals in ceilings and wall panels.