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Number of results: 5
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Effect Analysis of Loudspeaker’s Placement Angle and Direction on Frequency Response and Sound Pressure Level in TV Applications

Ibrahim Demirel
Archives of Acoustics | 2021 | vol. 46 | No 1 | 79-85 | DOI: 10.24425/aoa.2021.136562
Keywords acoustic transducers frequency measurement frequency response loudspeakers
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Abstract

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.
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Authors and Affiliations

Ibrahim Demirel
1
  1. Arçelik AS., Electronics HW Design, Turkey

Modified pressure-pressure sound intensity measurement method and its application to loudspeaker set directivity assessment

Witold Mickiewicz Michał Raczyński
Metrology and Measurement Systems | 2020 | vol. 27 | No 1 | 181-194 | DOI: 10.24425/mms.2020.131720
Keywords sound intensity pressure-pressure intensity probe loudspeaker set measurements
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Abstract

Sound intensity measurements using special sensors in a form of pressure-velocity and pressure-pressure probes are becoming more and more often the method of choice for characterization of sound sources. Its wider usability is blocked by the probes’ costs. This paper is on a possible modification of the well-known pressure-pressure sound intensity measurement method. In the proposed new approach a synchronized measurement procedure using only single microphone is used. The paper presents the basics of the sound intensity theory, a review of currently usedmethods of intensity measurement and requirements and limitations of the new method. In the proposed approach one microphone and a properly designed positioning system is used. The application of the method to study the directional characteristics of an active loudspeaker system have been described in detail. The obtained results were compared with those of measurements performed with a commercial p–u probe. The paper contains conclusions indicating advantages of the applied method in comparison with standard pressure measurement methods.

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Authors and Affiliations

Witold Mickiewicz
Michał Raczyński

Influence of Loudspeaker Configurations and Orientations on Sound Localization

Shu-Nung Yao
Archives of Acoustics | 2022 | vol. 47 | No 1 | 57-70 | DOI: 10.24425/aoa.2022.140732
Keywords audio quality ambisonics immersive sound loudspeaker array spatial effect virtual reality
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Abstract

As the virtual reality (VR) market is growing at a fast pace, numerous users and producers are emerging with the hope to navigate VR towards mainstream adoption. Although most solutions focus on providing highresolution and high-quality videos, the acoustics in VR is as important as visual cues for maintaining consistency with the natural world. We therefore investigate one of the most important audio solutions for VR applications: ambisonics. Several VR producers such as Google, HTC, and Facebook support the ambisonic audio format. Binaural ambisonics builds a virtual loudspeaker array over a VR headset, providing immersive sound. The configuration of the virtual loudspeaker influences the listening perception, as has been widely discussed in the literature. However, few studies have investigated the influence of the orientation of the virtual loudspeaker array. That is, the same loudspeaker arrays with different orientations can produce different spatial effects. This paper introduces a VR audio technique with optimal design and proposes a dual-mode audio solution. Both an objective measurement and a subjective listening test show that the proposed solution effectively enhances spatial audio quality.
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Authors and Affiliations

Shu-Nung Yao
1
  1. Department of Electrical Engineering, National Taipei University, No. 151, University Rd., Sanxia Dist., New Taipei City 237303, Taiwan

High-Directional Sound Propagation Over the Earth’s Surface

Denis S. Rakov Aleksandr S. Rakov Yury A. Chursin Vsevolod V. Pavlichev Artyom O. Igumnov
Archives of Acoustics | 2020 | vol. 45 | No 4 | 747-752 | DOI: 10.24425/aoa.2020.135280
Keywords parametric loudspeaker ultrasound primary frequency difference frequency radiation pattern outdoor propagation of sound sound attenuation
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Abstract

The article discusses the issues of accounting the direction pattern of parametric antenna array the propagation of sound over the Earth’s surface. As a radiator, a parametric antenna array is used. A description is given of measuring equipment and experimental research methods. The Delaney-Bezley model was used as a model of the Earth’s surface impedance. The research results showed the importance of accounting the direction pattern of parametric antenna array in predicting the sound pressure level of a propagating acoustic signal over the Earth’s surface. On the example of a difference signal with a frequency of 2 kHz, the calculation of the sound pressure level on a 100-meter path with the influence of the Earth’s surface is shown. The results obtained showed a good agreement between the theoretical calculation and experimental data.

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Authors and Affiliations

Denis S. Rakov
Aleksandr S. Rakov
Yury A. Chursin
Vsevolod V. Pavlichev
Artyom O. Igumnov

Measurement of Compound Sound Sources with Adaptive Spatial Radiation for Low-Frequency Active Noise Control Applications

Marios Giouvanakis Christos Sevastiadis George Papanikolaou
Archives of Acoustics | 2021 | vol. 46 | No 2 | 205-212 | DOI: 10.24425/aoa.2021.136576
Keywords Low-Bl loudspeakers compound sound sources adaptive spatial radiation active low-frequency noise control
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Abstract

The proposed compound sound sources for low-frequency noise control applications are composed of dipole sources. Their spatial radiation, which is critical in the modal field of small, closed spaces, is intended to be controlled with independent driving signals of each dipole. The need for small and efficient low-frequency elementary monopole sources led to the proposed vented sub-woofer loudspeaker design with low force factor (low-Bl) drivers. The investigated sources are set up in quadrupole configurations and measured in terms of polar near field response patterns to verify the theoretical predictions. The measurement results consist of the validation of the proposed compound sound sources on the implementation of active noise control problems in the low-frequency range. Also, their small size and modular construction make them interesting for use in other applications.
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Authors and Affiliations

Marios Giouvanakis
1
Christos Sevastiadis
1
George Papanikolaou
1
  1. Department of Electrical and Computer Engineering, Aristotle University of Thessaloniki

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