选取俄罗斯远东红皮云杉、东北长白鱼鳞云杉、西藏林芝云杉、美国西加云杉4个树种的试件,每树种2块共制作8块共振板,采用基于打击音的快速傅里叶变换(FFT)频谱方法分析共振板的振动特性,计算得出共振板不同方向的动态弹性模量、纵波传播速度、共振板边部剩余试件动弹性模量及共振板制作钢琴后的振动传播响应时间。利用共振板制作成试验用钢琴后,采用专家主观评价的方式对钢琴的声学品质进行评价。通过分析共振板振动特性参数与钢琴声学品质主观评价得分之间的关系得出,共振板y方向的振动特性参数与钢琴声学品质主观评价得分项目之间呈一定程度或显著的线性相关,而x方向的振动特性参数与主观评价得分项目之间的相关关系明显弱于y方向。因此,通过改善共振板y方向的振动特性可显著提高钢琴的声学品质,也说明了共振板y方向的振动特性参数检测对于钢琴声学品质评价的重要性。共振板y方向的振动特性参数与钢琴声学品质主观评价得分之间的相关性大于x方向的相关性,这一规律与音板上高、中音区域的琴弦排列和音板的y方向接近平行、低音区域琴弦排列及y方向的夹角小于x方向的结构特点有关。
Resonance board is an important component of piano, which predominates the acoustical quality of piano. This study attempts to establish a relationship between the vibration properties of resonance board and the acoustical quality of piano. The vibration properties of the two resonance boards made from each species of Picea glehnii, P. jezoensis, P. spinlosa and P. sitchensis were measured by analyzing the resonance spectrum based on FFT. The modules of elasticity (MOE), velocity of longitudinal wave (VL) of resonance board, the MOE of samples cut from the edge of the resonance board and the response time for vibration of soundboard of piano were calculated. Then the resonance boards were made to pianos, and piano experts evaluated their acoustical qualities. The results showed that it possesses a significant correlation between subjective evaluation and the experimental vibration properties of resonance board in the y-direction, but insignificant in the x-direction. That may be explained on the fact that the strings in high and intermediate frequency region array nearly parallel to y-direction,and that the angle between strings in low frequency region and y-direction is smaller than that between strings and x-direction of the soundboard. It suggests that the acoustical quality of piano may be bettered by improving the vibration properties in y-direction of resonance board.