Effective low-frequency and large-scale noise reduction are crucial in industrial applications. Conventional passive methods lack the effective low-frequency performance, and existing hybrid methods are costly to realize large-scale absorption. Hence, an effective and simply actuated solution for low-frequency and large-scale absorption is urgently needed. In this study, the low-frequency (100–500 Hz) quasi-perfect absorption characteristics of a hybrid structure which adopts the active force control (AFC) strategy are confirmed by experiment and its large-scale properties are analyzed. By using a flexible plate driven by a concentrated force as the AFC component and a passive MPP absorber, the large-scale model is established to absorb the normally incident plane wave. The structural–acoustic coupling characteristics are analyzed in detail and validated both by the experiment and finite element method. It is observed that by the acoustic–structural coupling, the frequency shift of the first structural mode will be inversely proportional to the total depth of the air cavities. Key parameters relating to the control force and other specifications of the hybrid system are analyzed to improve the broadband performance of the hybrid structure. Owing to the optimized control force, the coupled structural modes could be used to realize commendable large-scale (up to ten times larger than conventional hybrid absorber) absorptions. Compared with conventional methods, the designed absorber is able to realize low-frequency broadband quasi-perfect absorptions while dramatically reducing the number of secondary sources.

有效的低频和大规模降噪在工业应用中至关重要。常规的无源方法缺乏有效的低频性能，并且现有的混合方法实现大规模吸收的成本很高。因此，迫切需要一种有效且简便的低频和大规模吸收解决方案。在本研究中，通过实验确定了采用主动力控制（AFC）策略的混合结构的低频（100-500 Hz）准完美吸收特性，并分析了其大规模性能。通过使用由集中力驱动的柔性板作为AFC组件和无源MPP吸收器，可以建立大规模模型来吸收法向入射平面波。对结构-声耦合特性进行了详细分析，并通过实验和有限元方法对其进行了验证。可以看出，通过声-结构耦合，第一结构模式的频移将与气孔的总深度成反比。分析了与混合动力系统的控制力和其他规格有关的关键参数，以改善混合动力结构的宽带性能。由于优化的控制力，耦合的结构模式可用于实现值得称赞的大规模吸收（比常规混合吸收器大十倍）。与传统方法相比，设计的吸收器能够实现低频宽带准完美吸收，同时大大减少了次级光源的数量。