Archives of Acoustics, 46, 1, pp. 79–85, 2021
10.24425/aoa.2021.136562

Effect Analysis of Loudspeaker’s Placement Angle and Direction on Frequency Response and Sound Pressure Level in TV Applications

Ibrahim DEMIREL
Arçelik Aş. Electronics HW Design
Turkey

In a television, obtaining a good acoustic response is a challenging issue because of slim mechanical structures. The area dedicated for speaker’s placement is limited and inadequate space inside the cabinet of a TV prevents possible solutions to increase the sound performance. In addition, frame of the TV’s is getting narrower as the customers searching for the highest screen to body ratio. These designing aspects restrain optimal speaker positioning to achieve good sound performance. In this paper, an analysis related to speaker’s placement and mounting angle is proposed. A rotation setup compatible with a TV was prepared to measure different facing position of the speaker. This paper proposes the analysis of speaker’s rotation and facing direction in a flat panel television and its effects on sound pressure level together with deviation of the acoustic response. Measurement results are analyzed with an audio analyzer together with a statistics tool to achieve precise results.
Keywords: acoustic transducers; frequency measurement; frequency response; loudspeakers
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References

Aerts J.R.M., Dirckx J.J.J., Pintelon R. (2009), Measurement of nonlinear distortions in the vibration of acoustic transducers and acoustically driven membranes, Optics and Lasers in Engineering, 47(3–4): 419–430, doi: 10.1016/j.optlaseng.2007.12.010.

Bai M.R., Liu C.Y., Chen R.L. (2008), Optimization of microspeaker diaphragm pattern using combined finite element-lumped parameter models, IEEE Transactions on Magnetics, 44(8): 2049–2057, doi: 10.1109/TMAG.2008.923316.

Been K.H., Je Y.U.B., Lee H.S., Moon W.K. (2015), A parametric array PMUT loudspeaker with high efficiency and wide flat bandwidth, 2015 Transducers – 2015 18th International Conference on Solid-State Sensors, Actuators and Microsystems (TRANSDUCERS), Anchorage, AK, pp. 2097–2100, doi: 10.1109/TRANSDUCERS.2015.7181371.

Christensen S.T., Olhoff N. (1998), Shape optimization of a loudspeaker diaphragm with respect to sound directivity properties, Control and Cybernetics, 27(2): 177–198.

Cruz A., Martinez M.H. (2014), Frequency band displacement for optimizing acoustic boxes above the natural frequency of the loudspeaker, 2014 XIX Symposium on Image, Signal Processing and Artificial Vision, Colombia.

Dobrucki A. (2006), Diffraction correction of frequency response for loudspeaker in rectangular baffle, Archives of Acoustics, 31(4): 537–542.

Gan W. S., Kuo S. M., Toh C. W. (2001), Virtual bass for home entertainment, multimedia PC, game station and portable audio systems, IEEE Transactions on Consumer Electronics, 47(4): 787–796, doi: 10.1109/30.982790.

Hwang G.Y., Kim H.G., Hwang S.M., Kang B.S. (2002), Analysis of harmonic distortion due to uneven magnetic field in a microspeaker used for mobile phones, IEEE Transactions on Magnetics, 38(5): 2376–2378, doi: 10.1109/TMAG.2002.803579.

Hwang S.M., Kwon J.H., Hong K.S. (2005), Development of woofer microspeakers used for cellular phones, IEEE Transactions on Magnetics, 41(10): 3808–3810, doi: 10.1109/TMAG.2005.854928.

Jaskula M., Mickiewicz W. (2013), The effect of lowering the resonant frequency of the loudspeaker during impedance measurement as a function of the signal power, 18th International Conference on Methods & Models in Automation & Robotics (MMAR), Miedzyzdroje, Poland, 2013, pp. 701–704, doi: 10.1109/MMAR.2013.6669997.

Kim W., Jang G.W., Kim Y.Y. (2010), Microspeaker diaphragm optimization for widening the operating frequency band and increasing sound pressure level, IEEE Transactions on Magnetics, 46(1): 59–66, doi: 10.1109/TMAG.2009.2025271.

Kitagawa S., Kajikawa Y. (2009), Dynamic distortion measurement for linearization of loudspeaker systems, 2008 International Symposium on Intelligent Signal Processing and Communications Systems, Bangkok, Thailand, 2009, pp. 1–4, doi: 10.1109/ISPACS.2009.4806674..

Klippel W. (2005), Loudspeaker nonlinearities – causes, parameters, symptoms, 119th Audio Engineering Society (AES) Convention, USA.

Klippel W. (2005), Large signal performance of tweeters, micro speakers and horn drivers, 118th Audio Engineering Society (AES) Convention, Spain.

Kwon J.H., Hwang S.M., Kim K.S. (2007), Development of slim rectangular microspeaker used for minimultimedia phones, IEEE Transactions on Magnetics, 43(6): 2074–2706, doi: 10.1109/TMAG.2007.893784.

Lee C.M., Hwang S.M. (2011), Optimization of SPL and THD performance of microspeakers considering coupling effects, IEEE Transactions on Magnetics, 47(5): 934–937, doi: 10.1109/TMAG.2010.2089502.

Lee C.H., Kwon J.H., Kim K.S., Park J.H., Hwang S.M. (2010), Design and analysis of microspeakers to improve sound characteristics in a low frequency range, IEEE Transactions on Magnetics, 46(6): 2048–2051, doi: 10.1109/TMAG.2010.2042793.

Medley P., Billson D.R., Hutchins D.A., Davis A.J. (2019), A new design of thin and flexible loudspeaker, University of Warwick, UK.

Merit B., Lemarguand G. (2008), Ironless low frequency loudspeaker working under its resonance frequency, Archives of Acoustics, 33(4): 59–64.

Nakajima H., Sakata N., Hashiro K. (2015), Non-linear distortion reduction for a loudspeaker based on recursive source equalization, 2015 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), Brisbane, Australia, pp. 281–285, doi: 10.1109/ICASSP.2015.7177976.

Novak J. (1959), Performance of enclosures for low-resonance high-compliance loudspeakers, IRE Transactions on Audio, AU-7(5): 5–13, doi: 10.1109/TAU.1959.1166180.

Ouaegebeur N., Chaigne A. (2008), Mechanical resonances and geometrical nonlinearities in electrodynamic loudspeakers, Journal of the Audio Engineering Society, 56(6): 462–472.

Pawar S.J., Weng S., Huang J.H. (2012), Total harmonic distortion improvement for elliptical miniature loudspeaker based on suspension stiffness nonlinearity, IEEE Transactions on Consumer Electronics, 58(2): 221–227, doi: 10.1109/TCE.2012.6227416

Ravaud R., Lemarguand G., Lemarguand V. (2010), Ranking of the nonlinearities of electrodynamic loudspeakers, Archives of Acoustics, 35(1): 49–66.

Ravaud R., Lemarguand G., Roussel T. (2009), Time-varying non-linear modeling of electrodynamic loudspeakers, Applied Acoustics, 70(3): 450–458, doi: 10.1016/j.apacoust.2008.05.009

Rustighi E., Kaal W., Herold S., Kubbara A. (2018), Experimental characterisation of a flat dielectric elastomer loudspeaker, Actuators, 7(2): 28, doi: 10.3390/act7020028.

Satoh K., Takewa H., Iwasa M., Kikkawa T. (1997), A high fidelity small-sized loudspeaker, IEEE Transactions on Consumer Electronics, 43(3): 972–979, doi: 10.1109/30.628776.

Sun P., Park J.H., Kwon J. H., Hwang S.M. (2012), Development of slim speaker for use in flat TVs, IEEE Transactions on Magnetics, 48(11): 4148–4151, doi: 10.1109/TMAG.2012.2197676.

Takewa, H., Saiki S., Kano S., Inaba A. (2006), Slim-type speaker for flat panel televisions, IEEE Transactions on Consumer Electronics, 52(1): 189–195, doi: 10.1109/TCE.2006.1605046.

Zhu H., Rajamani R., Dudney J., Stelson K.A. (2003), Active noise control using a distributed mode flat panel loudspeaker, ISA Transactions, 43(3): 475–484, doi: 10.1016/S0019-0578(07)60148-7.




DOI: 10.24425/aoa.2021.136562

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