Snare Drum 定音鼓 Drums make use of circular membranes which have many modes of vibration. The excitation of the various modes depends upon where the drum is struck. The timpani is struck near the side to excite certain preferred modes. By contrast, the snare drum is struck in the center and excites the 01, 02, 03, modes. The fundamental frequency for an ideal circular membrane with no air damping effects is given by 鼓使用圆形膜片，这些膜片具有多种振动模式。激发不同的振动模式取决于鼓被敲击的位置。定音鼓通常在侧面敲击，以激发某些特定的振动模式。相比之下，军鼓则在中心敲击，激发01、02、03模式。对于理想情况下无空气阻尼效应的圆形膜片，其基频由

The snare drum is a two-headed drum, as is the bass drum and other orchestral and band drums used in Western music. On the snare drum, eight to ten wire-bound gut strings, or snares, usually are stretched across the lower of the two heads; they vibrate against the heads as the membranes are struck.

The two membranes of the snare drum are acoustically coupled to each other, particularly at the low frequencies. This coupling via the enclosed air acts to double the modes. The lower frequency member of the mode pair involves both heads moving in the same direction and for the higher mode they move oppositely.

Note that the value of the constant in the above equation for the frequency assumes that MKS units are used, as in the calculation for the circular membrane.