THE SHAPE AND THE ACOUSTICAL CHARACTERISTICS OF ANCIENT BELLS

Besides the Great Bell of the Yongle period, there are more than thirty ancient bells at the Temple of the Great Bell in West outskrit of Beijing. Most of them were cast in the Ming Dynasty and Qing Dynasty, only a few of them were cast in Song and Yuan Dynasty. The heights of these bells are in the range from 79 cm to 210 cm and corresponding weights are from 114 kg to 3108 kg. The largest and the smallest opening radius are 84 cm and 31.5 cm, respectively.
In this paper the dynamic spectrum of bell sound, beat frequency and sound decay for some of these bells are given. The relations between fundamental frequency and bell shape are discussed. For the bells with similar shape, fundamental frequency of bell is approximately proportional to T₀/R₀², where R₀, is opening radius of bells and T₀ is thickness of rim of bells. The subjective appraisal of the quality of bell sound is presented.