Mechanical Properties of Ferrofluids in Loudspeakers

Lemarquand G, Ravaud R, Lemarquand V, Depollier C. Mechanical Properties of Ferrofluids in Loudspeakers. In: AES Convention 125. Audio Engineering Society; 2008. Paper 7533. Available from: https://aes.org/publications/elibrary-page/?id=14685

@inproceedings{Lemarquand2008_14685,
  author = {Lemarquand, Guy and Ravaud, Romain and Lemarquand, Valerie and Depollier, Claude},
  title = {{Mechanical Properties of Ferrofluids in Loudspeakers}},
  booktitle = {AES Convention 125},
  note = {Paper 7533},
  year = {2008},
  month = oct,
  publisher = {Audio Engineering Society},
  url = {https://aes.org/publications/elibrary-page/?id=14685}
}

TY  - CPAPER
TI  - Mechanical Properties of Ferrofluids in Loudspeakers
AU  - Lemarquand, Guy
AU  - Ravaud, Romain
AU  - Lemarquand, Valerie
AU  - Depollier, Claude
T2  - AES Convention 125
M1  - Paper 7533
PY  - 2008
DA  - 2008/10/06
UR  - https://aes.org/publications/elibrary-page/?id=14685
PB  - Audio Engineering Society
LA  - en
AB  - This paper describes the mechanical properties of ferrofluid seals in ironless electrodynamic loudspeakers. The motor is constituted of several outer stacked ring permanent magnets. The inner moving part is a piston. In addition, two ferrofluid seals are used which replace the classical suspension. Indeed, these seals fulfill several functions. First, they ensure the airtightness between the loudspeaker faces. Second, they act as bearings and center the moving part. Finally, the ferrofluid seals also exert a pull back force on the moving piston. Both radial and axial forces exerted on the piston are calculated thanks to analytical formulations. Furthermore, the shape of the seal is discussed as well as the optimal quantity of ferrofluid. The seal capacity is also calculated.
ER  -