Experimental study of high-amplitude standing-wave field in standing-wave tube with uniform cross-section

The transfer function of sound pressure was used to analyze the properties of the peak and the valley resonance frequencies of a Standing-wave Tube with Uniform cross-Section(STUS).By improving the test system,the high-amplitude standing-wave field of 182.1 dB was obtained in the standing-wave tube with uniform cross-section excited at the first peak resonance frequency,meanwhile,the evolution properties of harmonics and the distortion of waveforms were studied experimentally from the first to the fifth peak resonances.It was found that,at the first peak resonance frequency,the distortion of waveform was the lowest and the saturation did not appeared even the sound pressure level reached 182.1 dB,and the saturation trend appeared at the third peak resonance frequency.With the contrast experiment on the valley resonance frequencies,it was found that,at the first valley resonance frequency,the sound pressure level was the highest and the distortion of waveform was the most serious.Under the same driving voltage of loudspeaker,the sound pressure level at the first peak resonance frequency was found higher than that at the first valley resonance frequency.It was suggested that to excite a standing-wave tube with uniform cross-section at the first peak resonance frequency would be a good choice to obtain the high-amplitude standing-wave field.