Loudspeakers as Microphones for Infrasound

Vanderkooy J. Loudspeakers as Microphones for Infrasound. In: AES Convention 143. Audio Engineering Society; 2017. Paper 9856. Available from: https://aes.org/publications/elibrary-page/?id=19253

@inproceedings{Vanderkooy2017_19253,
  author = {Vanderkooy, John},
  title = {{Loudspeakers as Microphones for Infrasound}},
  booktitle = {AES Convention 143},
  note = {Paper 9856},
  year = {2017},
  month = oct,
  publisher = {Audio Engineering Society},
  url = {https://aes.org/publications/elibrary-page/?id=19253}
}

TY  - CPAPER
TI  - Loudspeakers as Microphones for Infrasound
AU  - Vanderkooy, John
T2  - AES Convention 143
M1  - Paper 9856
PY  - 2017
DA  - 2017/10/06
UR  - https://aes.org/publications/elibrary-page/?id=19253
PB  - Audio Engineering Society
LA  - en
AB  - This paper shows that a sealed-box loudspeaker can be used as the sensor for a very high-performance infrasound microphone. Since the cone displacement essentially responds directly to infrasound pressure, the velocity-induced loudspeaker output must be electronically integrated to give a flat response. The undamped resonance peak of the loudspeaker is avoided by feeding the short-circuit voice coil current into the virtual ground input of an integrator op-amp. Design equations are given and a complete response analysis is presented. A prototype is compared with a conventional microphone used for infrasound measurement, showing the improved performance of the sealed-box loudspeaker design.
ER  -