実際の撞木が和鐘の音色に及ぼす影響 : 和鐘の音色の研究その2

抄録

We made a few experiments on a Japanese bell in order to clarify the relation between the character of striking rod and the timbre. In a previous paper, a model experiment was tried to investigate how the material, mass and speed of a striking block in place of the striking rod effected on the timbre of Japanese bell. From the results of model experiment, we tried some experiments using the striking rod in real use and got light on the relation of the size, mass and speed of the striking rod to the timbre. Moreover, we made some observations on the striking rod suitable for the sound of Japanese bell. The evaluation of the timbre was done in the same way as in the previous paper, namely, by the difference of sound spectra, which were given by the strengths of the fundamental tone, the first overtone and other tones. The sound spectra were obtained by means of a 1/3 octave analyzer. The results obtained from the above experiments are as follows: (1) The pattern of sound spectrum is varied by changing the position of the striking point. As the position is moved from the low place of bell to the high, the pattern is changed from "down type" and to "roof type" and "up type" as shown in Fig. 6. (2) Even though the striking speed of the striking rod is changed, the pattern explained in (1) is hardly changed, but the sound level is only varied. (3) When the ratio of the length of striking rod to the diameter of the bell (L/D) is ranged from 1. 5 to 1. 8, the pattern of sound spectrum becomes "roof type". On the contrary, this pattern is turned to "down type, when the ratio of L/D exceeds 3. 0. (4) When the load is applied on the striking rod within 2 kg and L/D is changed from 2. 1 to 3. 5, the pattern of sound spectrum is not varied. (5) The most important factor which effects on the sound spectrum does not consist in the ratio L/D, but in the weight of striking rod. If the weight of striking rod is smaller than a suitable weight the sound spectrum does not indicate "roof type", which seems to be agreeable. (6) There are the weight and striking speed of the striking rod suitable for magnifying the sound of bell.