Scanning the Magnetic Field of Electro-Dynamic Transducers

Klippel W. Scanning the Magnetic Field of Electro-Dynamic Transducers. In: AES Convention 130. Audio Engineering Society; 2011. Paper 8362. Available from: https://aes.org/publications/elibrary-page/?id=15829

@inproceedings{Klippel2011_15829,
  author = {Klippel, Wolfgang},
  title = {{Scanning the Magnetic Field of Electro-Dynamic Transducers}},
  booktitle = {AES Convention 130},
  note = {Paper 8362},
  year = {2011},
  month = may,
  publisher = {Audio Engineering Society},
  url = {https://aes.org/publications/elibrary-page/?id=15829}
}

TY  - CPAPER
TI  - Scanning the Magnetic Field of Electro-Dynamic Transducers
AU  - Klippel, Wolfgang
T2  - AES Convention 130
M1  - Paper 8362
PY  - 2011
DA  - 2011/05/06
UR  - https://aes.org/publications/elibrary-page/?id=15829
PB  - Audio Engineering Society
LA  - en
AB  - The magnetic flux density in the magnetic gap and the geometry of the moving coil determine the force factor Bl which is an important parameter of the electro-dynamical transducer. The magnitude of the. The paper presents a new measurement technique for scanning the flux density B(z, ö) on a cylindrical surface using a Hall sensor and robotics changing the position of the sensor versus vertical position z and angle ö. The results derived from the scanning process reveal the real B field in the gap considering the fringe field and irregularities in the magnetization which may initiate a rocking mode and rubbing of the voice coil at higher amplitudes. Using the geometry of the coil the static force factor Bl(x, i=0) can be calculated as a function of voice coil displacement x and compared with the dynamic force factor B(x,i) measured by using a voice coil current i. Discrepancies between dynamic and static force factor characteristics are discussed and conclusions for loudspeaker design and manufacturing are derived.
ER  -