Coupled speakers directivity measurements for small acoustic omnidirectional source development

• Autorzy: Chojnacki Bartłomiej , Kamisiński Tadeusz , Juros Klara , Kaczor Daniel
• Języki publikacji: EN

Abstrakty

EN

Acoustic monopole construction is unsolved task, which engineers try to solve for many years. In the past they constructed many innovative solutions, such as spark or laser-gap sound sources, but those concepts caused many equipment troubles. It is impossible to select type of the measurements signal for this kind of sound sources, also any sparks and laser beams can provide strong electromagnetic distortions around the operation zone. In current state of art we are trying to provide non-standard solutions while traditional omnidirectional sound source, based on spatial configuration of electroacoustic transducers, is not described correctly and can be expanded. Paper presents concept of acoustic monopole source based on coupled configuration for electrodynamic loudspeakers, similar to isobaric setup but non-constant volume between the speakers. By using FEM modelling we will present directivity patterns and project ideas, describing how overall results corresponds with geometrical parameters of speaker configuration and parameters. Presentation summary contain results of prototype device directivity patterns measurements. Received characteristics shows big potential in using cone-to-cone coupled speaker setup to reach acoustic monopole in frequency range defined by distance between transducers. Achieved knowledge allows to provide broadband, easy to build and small acoustic monopole with many possible applications.

Słowa kluczowe

EN

omnidirectional; point sound sources; coupled speaker set; sound radiation patterns

PL

źródła dźwięku punktowego; zestaw głośników; wzorce radiacji dźwięków

• Wydawca: Poznan University of Technology. Institute of Applied Mechanics
• Czasopismo: Vibrations in Physical Systems
• Rocznik: 2019
• Tom: Vol. 30, nr 1
• Strony: art. no. 2019128
• Opis fizyczny: Bibliogr. 11 poz., il. kolor., fot., wykr.

Twórcy

autor

Chojnacki Bartłomiej

• AGH University of Science and Technology, Mickiewicza Av. 30, 30-059 Cracow, Poland

autor

Kamisiński Tadeusz

• AGH University of Science and Technology, Mickiewicza Av. 30, 30-059 Cracow, Poland

autor

Juros Klara

• AGH University of Science and Technology, Mickiewicza Av. 30, 30-059 Cracow, Poland

autor

Kaczor Daniel

• AGH University of Science and Technology, Mickiewicza Av. 30, 30-059 Cracow, Poland

Bibliografia

• 1. M. L. S. Vercammen, Improving the accuracy of sound absorption measurement according to ISO 354, Proc. Int. Symp. Room Acoust., 2010.
• 2. G. Z. Yu, B. S. Xie, D. Rao, Directivity of spherical polyhedron sound source used in near-field HRTF measurements, Chinese Phys. Lett., 2010.
• 3. A. Majchrzak, B. Chojnacki, M. Sobolewska, K. Baruch, A. Pilch, The Measurement of Sound Scattering in a 1:8 Scale-Validation of the Measurement Stand and Procedure, In: INTER-NOISE and NOISE-CON Congress and Conference Proceedings, (2018) 3287 - 94.
• 4. J. T. Larsen, J. R. Larsen, Isobaric loudspeaker, 1997.
• 5. C. Hak, R. H. C. Wenmaekers, J. P. M. Hak, L. C. J. van Luxemburg, The source directivity of a dodecahedron sound source determined by stepwise rotation, In: Proceedings of Forum Acusticum, 2011.
• 6. I. B. Witew, G. K. Behler, Uncertainties in measurement of single number parameters in room acoustics. Requirements Sources for Sound Data Analysis, 2291 - 5.
• 7. D. Shearer, Measuring absorption below 100Hz with a P-U sensor, 2016.
• 8. K. Baruch, A. Majchrzak, B. Przysucha, A. Szeląg, T. Kamisiński, The effect of changes in atmospheric conditions on the measured sound absorption coefficients of materials for scale model tests, Appl. Acoust., 1412018, 150 - 260.
• 9. R. Alden, Speaker Building 201: with 11 Completely Designed Speaker Systems including a 5.1 Home Theater System, Audio Amateur Press 2004.
• 10. https://www.vueaudio.com/isobaric-subwoofer-design/
• 11. B. Chojnacki, M. Ziobro, J. Rubacha, Piezoelektryczne wszechkierunkowe źródło dźwięku do akustycznych badań w skali w zakresie ultradźwięków, In: A. Pilch, editor. Studium badawcze młodych akustyków. Kraków, Wydawnictwo AGH 2016.

Uwagi

Opracowanie rekordu ze środków MNiSW, umowa Nr 461252 w ramach programu "Społeczna odpowiedzialność nauki" - moduł: Popularyzacja nauki i promocja sportu (2020).