反对称谐振
指这样一种模态：在同一谐振器的对称位置处，振幅的相位相差 180°（即相位恰好相反）；若只考虑振幅的大小（绝对值），该模态则呈现为对称的。由于振幅相位相差 180°，对称位置之间必然至少存在一个波节，在这种情况下该谐振必然是非轴向的。
示例：某条形变幅杆存在这样一种谐振——变幅杆端面一端在同一瞬时的振幅为 +100 微米，而端面另一端在同一瞬时的振幅为 -90 微米。请注意，端面两端的振幅相位（符号）相反，这表明其为反对称模态，尽管振幅的大小不一定相等（100 微米对 90 微米）。
Antisymmetric resonance
A mode in which the amplitude is 180° out of phase (i.e., exactly opposite in phase) at symmetric locations on the same resonator and for which the mode would appear symmetric if only the magnitudes (absolute values) of the amplitude were considered. Since the amplitudes are 180° out of phase, there must be at least one node between the symmetric locations in which case the resonance must be nonaxial.
Example: a bar horn has a resonance where the instantaneous amplitude at one end of the horn face is +100 microns, while at the same instant the amplitude at the other end of the horn face is -90 microns. Note that the amplitudes at either end of the horn face are opposite in phase (sign), which indicates an antisymmetric mode, even though the magnitude of the amplitudes is not necessarily equal (100 microns versus 90 microns).
Also see —
Asymmetric amplitude
Symmetric resonance