A simplified sound directivity measuring method based on the Chinese traditional pentatonic scale for the small Pipa of Dong Nationality

The small Pipa of Dong Nationality is a special four-string plucked musical instrument created by ancient minorities in the southwest of China with a history of hundreds of years. In order to re-examine a reasonable acoustic reference for the performance, composition, recording and development of this unique ethnic instrument, and due to the special sound directivity characteristic of the small Pipa, a simplified method of its measurement is introduced in this paper. Based on the Chinese traditional pentatonic scale and performing form, in an acoustical treated room, a spherical array in three circular planes with eight directional microphones of each is set to record the SPL at one meter away from the performer. Then the normalized SPL is used to represent the multi-directivity, an average spectrum to show the frequency response. Furthermore, the geographical economic environment and its time-space heterogeneity is the essential precondition for the music production, formation, developing and changing. In order to obtain greater loudness and better sound quality, a sound recording program suitable for the small Pipa is also proposed in this paper.