Variable Fractional Order Analysis of Loudspeaker Transducers: Theory, Simulations, Measurements, and Synthesis

Bezzola A, Brunet P, Yuan S. Variable Fractional Order Analysis of Loudspeaker Transducers: Theory, Simulations, Measurements, and Synthesis. In: AES Convention 143. Audio Engineering Society; 2017. Paper 9839. Available from: https://aes.org/publications/elibrary-page/?id=19236

@inproceedings{Bezzola2017_19236,
  author = {Bezzola, Andri and Brunet, Pascal and Yuan, Shenli},
  title = {{Variable Fractional Order Analysis of Loudspeaker Transducers: Theory, Simulations, Measurements, and Synthesis}},
  booktitle = {AES Convention 143},
  note = {Paper 9839},
  year = {2017},
  month = oct,
  publisher = {Audio Engineering Society},
  url = {https://aes.org/publications/elibrary-page/?id=19236}
}

TY  - CPAPER
TI  - Variable Fractional Order Analysis of Loudspeaker Transducers: Theory, Simulations, Measurements, and Synthesis
AU  - Bezzola, Andri
AU  - Brunet, Pascal
AU  - Yuan, Shenli
T2  - AES Convention 143
M1  - Paper 9839
PY  - 2017
DA  - 2017/10/06
UR  - https://aes.org/publications/elibrary-page/?id=19236
PB  - Audio Engineering Society
LA  - en
AB  - Loudspeaker transducer models with fractional derivatives can accurately approximate the inductive part of the voice coil impedance of a transducer over a wide frequency band, while maintaining the number of fitting parameters to a minimum. Analytical solutions to Maxwell equations in infinite lossy coils can also be interpreted as fractional derivative models. However, they suggest that the fractional order a cannot be a constant, but rather a function of frequency that takes on values between 1/2 and 1. This paper uses Finite Element (FEM) simulations to bridge the gap between the theoretical first-principles approach and lumped parameter models using fractional derivatives. The study explores the dependence of a on frequency for idealized infinite and finite cores as well as in four real loudspeaker transducers. To better match the measured impedances and frequency-dependent a values we propose to represent the voice coil impedance by a cascade of R-L sections.
ER  -