Manipulation of Low-Frequency Sound with a Tunable Active Metamaterial Panel

We propose the design of a flat active wall panel and demonstrate its effectiveness in modulating impedance, which can lead to total absorption incident sound waves low-frequency range 50--120 Hz, or alter reflection phase. Such an acoustic frequency is usually most difficult handle for passive components, owing long wavelength, consequently, bulky size materials required. The actuated by piezoelectric transducer, with vibrational displacement amplified specially designed mechanical amplifier. Through both simulations impedance-tube experiments, we show that simply tuning panel's amplitude vary impedance from hard wall, matching air (leading absorption), zero phase reversal). No feedback loop necessary active-panel device; only initial adjustment during installation necessary. simulate room-acoustics application 1 \ifmmode\times\else\texttimes\fi{} ${\mathrm{m}}^{2}$ occupies 1/48 area room it introduce switchable elements audio experience.