Abstract: In this paper, the resonance frequency of the sound column is investigated both theoretically and experimentally, and the efficiency of the sound column at resonant frequency is also calculated. It is shown that the resonance frequency varies linearly with the number N of the loudspeakers in the sound column, and the efficiency of the sound column at resonant frequency is directly proportional to the number N of the loudspeakers if N<3, and it tends to increase slower gradually if N>4.
We have also proved that the radiation of the loudspeakers treated in according with the radiation of a plane piston on the terminal of the long tube in the sound column is fairly good coincident with the results of the experiment.