Low-frequency acoustic isolation performance of Helmholtz cavity acoustic metamaterials with bilateral single openings

In this study, we designed a single-opening Helmholtz chamber type acoustic metamaterial with two sides. The complexity of the open channel results in the material having a low frequency of the first sound insulation peak and excellent sound insulation performance. The research indicates that this type of acoustic metamaterial has many sound insulation peaks in the frequency range of 20–1200 Hz. The first sound insulation peak exhibits a low frequency of 36 Hz and a bandwidth of 10 Hz, resulting in a maximum sound insulation volume of 43.15 dB. We used an equivalent model to perform sound-force analogy and the transfer matrix method to construct the equivalent model of this type of metamaterial. We studied the resonance frequencies of multiple sound insulation peaks and used 3D printing technology to obtain physical samples for experimental analysis. The results obtained from physical experiments are consistent with the theoretical calculation results.