partial oscillation: Designates a term in loudspeaker technology. Idealized theoretically, a speakerMembran vibrate like a non-deformable piston. In practice, however, undesired wave movements occur on the membrane surface - similar to the surface of water: Partial areas of the membrane vibrate forwards, while other areas simultaneously vibrate backwards.
This phenomenon is more pronounced when the wavelength to be radiated is smaller than the diameter of the membrane. Partial vibrations can even form "standing waves" between the center and edge of the membrane. As a result of partial oscillations, parts of the actual music signal can sometimes be erased (see interference), which then turn an uneven frequency response conditional.