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Transducer Parameters

Transducer Parameters

Small signal lumped parameters

  • Resonance frequency fs
  • Mechanical quality factor Qms
  • Electrical quality factor Qes
  • DC resistance Re
  • Force factor Bl(x=0)
  • Mechanical resistance Rms(v=0)
  • Stiffness Kms(x=0) and compliance Cms(x=0)
  • Additional Thiele-Small parameters (e.g. Vas)
  • Visco-elastic parameter (creep factor λ)
  • Lossy inductance parameters (Wright, Leach, LR2 model)

Transducer nonlinearities (curve shape)

  • Force factor Bl(x) versus displacement x
  • Mechanical compliance Cms(x) versus displacement x
  • Mechanical stiffness Kms(x) versus displacement x
  • Incremental stiffness Kinc(x) versus displacement x
  • Inductance L(x,i) versus displacement x and current i
  • Mechanical resistance Rms(v) versus velocity v
  • Force-deflection curve F(x)

Single-valued nonlinear parameters

  • Voice coil offset Xoffset
  • Suspension asymmetry Ak
  • Maximal peak displacement Xmax
  • Force factor limited peak displacement Xbi
  • Suspension limited peak displacement Xc
  • Inductance limited peak displacement XL
  • Stiffness Kms(x=0) at the voice rest position
  • Force factor Bl(x=0) at the voice coil rest position
  • Effective stiffness related to effective resonance frequency
  • Symmetry point xsym in force factor curve

Electrical impedance

  • Amplitude and phase response
  • Nominal electrical impedance Zn
  • Impedance measured by using a large signal model

Parameters of the enclosure

  • Port resonance fb
  • Quality factor Qlb of vented enclosure