Displacement-resonance and velocity-resonance of loudspeaker
Zhang Pingk · Journal of Central South University(Science and Technology) · 2013
It is proved that the displacement resonance frequency of general speakers or sealed speaker box is much lower than its velocity resonance frequency. The displacement resonance will disappear when the total quality factor QT of the speaker system is less than 0.707. At this time, when constant amplitude pure tone signals drive, the lower the frequency is the higher the amplitude of the loudspeaker cones appears. Particularly, the signal which has much lower frequency will lead to serious distortion even damage the sealed speaker box which has higher velocity resonance frequency and smaller QT. This is because too large amplitude of loudspeaker cones will make the motion of voice coil exceed the linear region of pot-shaped magnetic field. So, for this kind of speaker box, high-pass networks should be set in the amplifier to cut the too low frequency signal.