主题：第三届电声技术国际研讨会于2011年11月12日―13日在深圳虚拟大学园召开

Steve F. Temme，Brian Fallon，Pascal Brunet

所有制造商都希望在他们的装配线上生产出优良声品质、高产量的扬声器和耳机。在不牺牲产品质量的前提下，一种提高产量的方式是用自动可感知破擦 声检测模型取代传统检测模型，对产品进行破擦声缺损检测。这种模型仅仅用于检测可听破擦声缺损而非所有的破擦声缺损。自动可感知破擦声测量装置不仅能够重 现听音员获得的结果，还能提高生产量并且能与自动生产线融为一体。

本文阐述了一种新型的用于自动可感知破擦声检测的方法，并讨论其原理，同时与其他破擦声检测方法所得出的结果进行比较。此外，本文还阐述了此方法如何使得限度设置较传统方式更为简单，从而能更便捷地在生产线上得到应用。

 

 

Steve F. Temme，Brian Fallon，Pascal Brunet

All manufacturers want two things from their loudspeaker and headphone assembly lines – good sound quality and high yields. One way that higher yields can be achieved without sacrificing product quality is to detect Rub & Buzz defects using an automated PERCEPTUAL Rub & Buzz detection model rather than a conventional one. This is a model which detects only AUDIBLE Rub & Buzz faults rather than ALL Rub & Buzz faults. Automated perceptual Rub & Buzz measurement better reproduces the results obtained by a human listener but with higher throughput and full integration with automated production lines.

This paper explains a newly-developed method for automated perceptual Rub & Buzz detection, discusses the theory behind it, and shows test results in comparison to other Rub & Buzz detection methods. It also explains how this method makes limit setting much simpler than with conventional methods which makes it much easier for use on the production line.

史密特·葛瑞格

一个典型的扬声器最终测试需要测量包含10个或者更多的参数，每个参数都有其对应的公差来判定扬声器是否通过测试，进而影响产线的良率。本文介绍了工业上常用公差计算方法和步骤，并为选择正确的公差方案来实现良率、质量以及产量的最大化，提供了系统的指导。

 

 

Gregor Schmidle

A typical end-of-line loudspeaker test comprises ten or more different parameters tested. Each parameter has its own pass/fail limits contributing to the overall test result of the loudspeaker and therefore to the yield of the production line. This paper gives a comprehensive overview about commonly used limit calculation methods and procedures in the industry. It also delivers systematic guidance for choosing the right limit scheme for maximizing yield, quality and throughput.

D. B. (Don) Keele, Jr.

Seven types of loudspeaker line arrays were ranked considering eight performance parameters including 1) Beamwidth uniformity, 2) Directivity uniformity, 3) Sound field uniformity, 4) Side lobe suppression, 5) Uniformity of polar response, 6) Smoothness of off-axis frequency response, 7) Sound pressure rolloff versus distance, and 8) Near-far polar pattern uniformity. Line arrays analyzed include: 1. Un-shaded straight-line array, 2. Hann-shaded straight-line array, 3. “J”-line array, 4. Spiral- or progressive-line array, 5. Un-shaded circular-arc array, 6. CBT circular-arc array, and 7.CBT delay-curved straight-line array. All arrays were analyzed assuming no extra drive signal processing other than frequency-independent shading. A weighted performance analysis yielded the following ranking from best to worse 6, 7, 5, 4, 3, 2, 1, with the CBT Legendre-shaded circular-arc array on top and the un-shaded straight-line array on the bottom.

刘云峰, 沈勇, 董桂官, 蒋伟

利用QR时间延迟、QR相位延迟、采用sinc函数理论或二次剩余序列设置阵列等方法对多点激励源的声梁水平方向指向性进行优化， 指向性与声功率级二者兼顾，声梁在偏离轴线方向其频率响应也随之得到改善；经过优化后得到的宽指向性声梁适用于会议室、教室和平板电视等场合，且安装便 捷，美观大方。

 

 

Liu Yun-feng, Shen Yong, Dong Gui-guan , Jiang Wei

After the optimization of both the sound girder's directivity in the horizontal direction and its acoustic power by QR timing or phase delay, sinc setup or quadratic rasidue setup, its frequency response is also improved in directions deviated from its axis. Omni-directivity sound girder can be installed easily in classrooms, meeting rooms , flat panel TVs and looks artistic.

Xiaoli Zhong, Bosun Xie

Virtual auditory display (VAD) recreates desired spatial auditory events by synthesizing binaural signals with head-related transfer function (HRTF) and rendering them through headphone. VAD has been widely used in research of binaural hearing as well as consumer electronics and entertainments in recent decades. Existing studies have emphasized that faithful performance of VAD needs incorporating individualized HRTFs. Empirical measurement is a conventional way to accurately obtain individualized HRTFs. However, it is difficult to measure individualized HRTFs for each of potential users with high spatial resolution. A variety of approaches to approximating or customizing individualized HRTFs have been developed, which become hot issues in research of VAD. Although moderate success has been achieved, further validation and improvement of those customization approaches are required. This article reviews latest development in this field with emphasis on existing problems and future directions.

冯声振，王超

有源消噪技术从工业噪声控制走向移动终端产品，提升用户在任何嘈杂的场合听音乐或是通话时的信噪比和可懂度等聆听体验。针对在移动终端应用有源消噪技术所面临的信号因果性问题，提出了模拟系统和数字系统两种解决方案。其中，瑞声科技推出的有源消噪模拟芯片EMT6903，可方便地应用于移动终端产品。在某型号开放式耳塞和手机上应用后，得到了200—2500 Hz以上的消噪频带，平均降噪量达到13—16 dB以上，同时对回放音频的音质没有影响，主观聆听体验提升明显。

 

 

FENG Shen-zhen, WANG Chao

Active noise cancellation (ANC) technology becomes applicable in mobile terminal products, not only in industry noise control. The experience of listening including signal to noise ratio (SNR) and intelligibility will be improved when enjoying music or calling in a noisy environment. Considered the signal causality problem when ANC is employed in mobile terminals, both an analog system solution and a digital system solution are proposed. Among these, an analog chip EMT6903 provided by AAC Technologies can be applied into mobile terminal products conveniently. Tests on some earphone and mobile phone show that the band of noise cancellation is over 200 ~ 2500 Hz and noise cancellation is above 13 ~ 16 dB in average. In the mean time, there is no loss of original playback audio quality and subjective experience increases.

蒋伟，乐意，杨小军，沈勇

吸声材料的吸声系数的准确度是建筑声学研究和设计的基础，而吸声系数又是通过在混响室中测量混响时间来计算得到的。本文通过统计声学和波动声学 的基本原理对混响室中混响时间测量的空间偏差和重复偏差产生的原因进行了分析，并在南京大学混响室内进行了定量的试验统计研究，找到了影响混响时间测量空 间偏差和重复偏差的因数，并提出了改善建议。

 

 

Jiang Wei, Le Yi, Yang Xiao-jun, Shen Yong

The accuracy of the absorption coefficient is the base of architectural acoustics research and design. Now the absorption coefficient is calculated by the reverberation time measured in the reverberation room. The cause of the spatial variance and ensemble variance of the reverberation time are found, and some practical suggestions are proposed.

陈瑞祥

扬声器振动元件材料的杨氏模量的准确测量,长期以来存在疑问，曾经有过多种的测试方法，但是均存在明显的缺陷和不足，原因是扬声器振动元件所用 材料的杨氏模量数值跨度比较大，而绝对值比较小，因此传统的杨氏模量测试方法在扬声器振动元件材料的测量中不实用.本文介绍的测试方法是利用光学投影仪将 被测样条的挠曲变形放大并测量其挠度，再利用近似微分方程进行计算得到准确的杨氏模量值，该方法简单、可以多次重复测试、精度满足工程设计需要。

 

 

Chen Rui-xiang

Young’s modulus of material using in loudspeaker vibrational components can’t be measured accurately for long time. There were some method be introduced before. But there are blemish in it obviously. There are very wide range in numerical value was main reason and absolute value is very small compare with metal. So Young’s modulus of meterial using in loudspeaker viberational components can’t be measured by traditional measuring method. A newly measure method is introduced here. Firstly it measure the deflection of sample by optics projector to blowup flex image. Then calculate Young’s modulus value by approximate equation. The method is simple and repeatable. Measure’s precision meet the needs of engineering.

Jose Martinez, Jaime Ramis, Enrique Segovia, Alejandro Espí, Jesús Carbajo

本文提供了小尺寸直接辐射式扬声器单元在追求低频的高声压级（SPL）时有可能遇到的问题的解决方法。为了定量的分析诸如支撑系统（弹波）波纹的个数、支撑系统之间的距离或者扬声器结构中不均衡的应力之类扬声器单元结构及材料特性的微小变化的影响，本文将利用有限元模型（FEM）深入研究扬声器振动系统的动态特性。以某个6英寸扬声器单元为例，比较了理论模拟和实验测量的结果。

众所周知，振动系统的辐射声功率是由振膜所推动的空气量及气流的速度决定的。因此，振动系统在有限元模型的帮助下经过仔细的设计和优化可以获得 大的振膜位移。为了确定扬声器单元振动系统的动态特性和模型各节点的位移，利用模态分析和谐波分析工具获得合适的模型库。这项工作在某些场合相当关键。而 且在这个过程中会发现一些不足，通过模型的改进可以获得更好的结果。另外，将探讨如何进一步改进锥盆和防尘帽，以增加辐射阻，尽量提高扬声器的效率。

最后，研究了以“短音圈”结构（音圈卷幅小于磁隙高度）代替传统常见的“长音圈”（音圈卷幅大于磁隙高度）结构的可能性。

 

 

Jose Martinez, Jaime Ramis, Enrique Segovia, Alejandro Espí, Jesús Carbajo

This paper intends to provide solutions to some of the problems that may appear in small size direct radiation loudspeakers when trying to reach high Sound Pressure Level (SPL) at low frequencies. A deep study related to structural dynamic behaviour of the moving assembly using a finite elements model (FEM) was necessary in order to quantify the influence of small changes in geometry and material characteristics such as number of folds in the suspensions (spiders), distance between these suspensions or effect of unbalanced forces inherent in the speaker construction. Theoretical and experimental work is carried out at the same time and results are compared using a six inch loudspeaker development as reference.

It is well known that acoustic power radiated by vibrant systems depends on the amount of air moved by the diaphragm and its velocity (air flow). For this reason, large diaphragm displacements are proposed and moving assembly must be carefully designed and optimized, solving all the existing problems with the aid of a finite elements model.

Modal base was obtained with the use of modal and harmonic analysis tools in order to determine dynamic behaviour of the moving assembly and also the displacements of every model nodes, which may be especially critical in some locations. Moreover, the work also describes these drawbacks and proposes solutions to reach better results. In addition, further improvements – cone and dust cap – are investigated in order to increase radiation resistance and thus maximizing loudspeaker’s efficiency.

Finally, the possibility of considering an underhung geometry instead of the overhung one, which is the most conventional one, is also studied for the voice coil assembly.

 

Richard Little

这篇报告已经提前在声学楼年会发布了！