Study on the predictions of acoustic characteristics of microspeakers based on the specific airflow resistance of ventilation materials: Mesh type

Abstract

In this study is presented a method for predicting the acoustic characteristics of microspeakers with mesh-type ventilation materials that combines specific airflow resistance with equivalent circuit model. The specific airflow resistances of eight types of ventilation materials were quantified using a self-made measurement system. These materials were then used to simulate the acoustic properties of 40 φ and 20 φ microspeakers, respectively. The results were compared with simulation results obtained using Dr. Maa’s porous plate acoustic impedance and actual measurements. After applying a stable correction factor, the self-made measurement system accurately determined specific airflow resistance values with high reproducibility and stability. A regression curve based on scanning electron microscope obtained porosity and measured specific airflow resistance effectively predicted the specific airflow resistance of materials with known porosity. Applying these values to acoustic simulations, the proposed method significantly improved accuracy, outperforming Dr. Maa’s method by a factor of six, and closely matched actual measurements. This innovative approach is versatile and applicable to various conditions and types of ventilation materials, as well as enhances predictions of their impact on electro-acoustic product performance.