How to Optimize the Acoustic Performance of Perforated GRC Panels?

Optimizing the acoustic performance of perforated GRC panels requires systematic design across three aspects: hole parameters, rear cavity, and material properties. Based on experience from multiple concert hall and conference center projects, Qinglong Group has developed a technical solution that jointly optimizes perforation rate, hole diameter, and cavity depth.

Hole parameter design is the foundation of acoustic optimization. Through acoustic simulation, Qinglong Group determined the optimal perforation rate to be 8%-15%, with hole diameters of 2-5mm. In the Zengcheng Cultural Conference Center project, a tapered hole design (4mm surface diameter, 6mm rear diameter) was adopted, effectively broadening the sound absorption frequency band. Hole spacing is controlled at 2-3 times the hole diameter to avoid sound wave interference that creates peaks and troughs.

Rear cavity design determines the resonance frequency. The cavity depth is typically 50-100mm, filled with centrifugal glass wool (density 32kg/m³). By adjusting the cavity depth, the main sound absorption frequency band can be tuned to the 500-2000Hz range, where human hearing is most sensitive to speech. In multi-cavity designs, cavities of different depths are used in combination to achieve broadband sound absorption.

The material's own properties also affect acoustic performance. Qinglong Group incorporates rubber particles (1-3mm particle size, 3%-5% dosage) into the GRC matrix to improve damping performance. Surface treatment uses a microporous coating to avoid sealing the holes and impairing sound absorption. This comprehensive optimization enables perforated GRC panels to achieve a noise reduction coefficient (NRC) above 0.7.