Figure 4
From: Sound Pressure Level Gain in an Acoustic Metamaterial Cavity
Enhancing the amplification using a quarter-wave resonator:
(a) schematic of metamaterial cavity (Sample 1) with a quarter-wave resonator; incoming acoustic signal was amplified as it was reflected back inside the cavity by an acoustic hard wall; (b) SPLs inside the quarter-wave resonator enhanced the metamaterial cavity with three different gap sizes (C) and the metamaterial cavity with no quarter-wave resonator (O); (c) sound intensity magnitude (RMS) and (d) particle velocity (RMS) across the metamaterial cavity enhanced by the quarter-wave resonator for three different gap sizes.
