How effective are polyester fiber acoustic panels?

Polyester fiber acoustic panels perform particularly well in the mid-to-high frequency range, with a noise reduction coefficient (NRC) typically between 0.8 and 1.10. Within the 125–4000Hz noise range, the NRC can reach over 0.9, making it a broadband, highly efficient sound absorber. By leaving a cavity in the back, the sound absorption performance can be further enhanced.