Hi. The experiment is set up so that a loudspeaker is suspended oer a column of air. When sound is sent through the air column, the particls of air will vibrate. The amplitude is related to the loudness of the sound so when the particles vibrate at their maximum amplitude (resonance) the sound will be at its loudest. Would you expect the resonant frequency to be higher or lower of the air-column was longer? I would say the resonant frequency to be higher because the natural frequency of the air particles would be higher, is this correct?