A single layer of four parallel-arranged inhomogeneous microperforated panels (iMPP) absorber is proposed to achieve low-frequency sound absorption and wider frequency bandwidth. The hole diameter of the four parallel-arranged iMPP is set to be equal to or less than 1 mm. The theoretical formula for calculating the absorption coefficient under normal incident sound is established based on an electrical equivalent circuit model (ECM). The parametric study has been performed on the MATLAB software, and the expected results are obtained. The results indicate that the proposed model can produce a wider absorption bandwidth of 195–455 Hz in the low-frequency region with an average absorption coefficient of more than 90% (α = 0.91). To achieve the desired effect, the absorption coefficient and the bandwidth can be tuned by adjusting the aperture size, perforation ratio, thickness of iMPP with depth and width of the back cavity. Also, it is found that iMPP can produce wider bandgaps with good absorption peaks in the low-frequency region by designing sub-MPP of smaller hole diameter, large perforation ratio, and with large cavity depths and the sub-MPP of large hole diameter, small perforation ratio, and with short cavity depths. The finite element method has been employed on COMSOL Multiphysics 5.5a to simulate the acoustic absorption performance of the model and compared with the ECM-based predicted and square impedance tube-based experimental results. Compared with other homogeneous MPPs of different arrangements, this absorber provides exceptional absorption performance in a low-frequency range due to its lightweight structure, and convenient manufacturing availability, this enhanced form of iMPP absorber has great potential in acoustics and noise control applications.

提出了单层四个平行排列的非均匀微穿孔板 (iMPP) 吸收器，以实现低频吸声和更宽的频率带宽。四个平行排列的iMPP的孔径设置为等于或小于1mm。基于电气等效电路模型（ECM）建立了计算法向入射声下吸收系数的理论公式。在MATLAB软件上进行了参数研究，得到了预期的结果。结果表明，该模型可以在低频区域产生 195-455 Hz 的更宽吸收带宽，平均吸收系数超过 90% ( α = 0.91）。为了达到预期的效果，可以通过调整孔径大小、穿孔率、iMPP 的厚度与后腔的深度和宽度来调整吸收系数和带宽。此外，还发现通过设计孔径较小、穿孔率大、腔深大的sub-MPP和大孔径的sub-MPP，iMPP可以产生更宽的带隙，在低频区域具有良好的吸收峰，穿孔率小，腔深短。已在 COMSOL Multiphysics 5.5a 上采用有限元方法来模拟模型的吸声性能，并与基于 ECM 的预测和基于方阻抗管的实验结果进行比较。与其他不同排列的同类 MPP 相比，