Beam Dithering: Acoustic Feedback Control Using a Modulated-Directivity Loudspeaker Array

Elko G, Goodwin M. Beam Dithering: Acoustic Feedback Control Using a Modulated-Directivity Loudspeaker Array. In: AES Convention 93. Audio Engineering Society; 1992. Paper 3384. Available from: https://aes.org/publications/elibrary-page/?id=6749

@inproceedings{Elko1992_6749,
  author = {Elko, Gary and Goodwin, Michael},
  title = {{Beam Dithering: Acoustic Feedback Control Using a Modulated-Directivity Loudspeaker Array}},
  booktitle = {AES Convention 93},
  note = {Paper 3384},
  year = {1992},
  month = oct,
  publisher = {Audio Engineering Society},
  url = {https://aes.org/publications/elibrary-page/?id=6749}
}

TY  - CPAPER
TI  - Beam Dithering: Acoustic Feedback Control Using a Modulated-Directivity Loudspeaker Array
AU  - Elko, Gary
AU  - Goodwin, Michael
T2  - AES Convention 93
M1  - Paper 3384
PY  - 1992
DA  - 1992/10/06
UR  - https://aes.org/publications/elibrary-page/?id=6749
PB  - Audio Engineering Society
LA  - en
AB  - The problem of acoustic feedback in public address systems has been with us since the advent of the electronic amplifier (and, of course, the loudspeaker and microphone). Various schemes to ameliorate the problem have been proposed: filters, frequency shifting, directional transducers, etc. One possible technique that has not been explored in the past is to allow the loudspeaker directivity to be modulated in time. The modal excitation of the room can be time-varied, thereby averaging the response at a point. Such directivity dithering reduces the peak response in the system transfer function (between loudspeaker and microphone). We have constructed a three-octave digital beamforming loudspeaker array whose directivity can easily be modified as a function of time. The presentation will discuss the theory of the use of the modulated directivity and report on the design and construction of the beamforming loudspeaker array.
ER  -