Spider resonance frequency assessment using normal-incidence,transmission loss measurements

The spider in a loudspeaker driver ideally only behaves as a spring, providing a restoring force to bring the loudspeaker diaphragm back to its rest position. In concert with the surround, it also helps ensure that the motion of the diaphragm is unidirectional. Because of the finite area and mass of the spider, an independent resonance of the spider is possible, which serves to decrease the energy radiated from the loudspeaker at the spider’s resonance frequency. The goal of this work is to develop a new technique to identify the spider’s resonance frequency before the loudspeaker driver is ever installed into a box. A plane-wave tube method to assess the parameters through measurement of the sound transmission through the loudspeaker was developed previously [Leishman and Anderson, J. Acoust. Soc. Am. 134(1) (2013)] and will be utilized in this work. Here, the two-microphone transfer function technique and the two-load method are used to handle non-anechoic terminations to the tube. The assessment of this resonance frequency from transmission loss measurements will be compared to the ability to assess it from electrical impedance measurements.