玩转RMAA6.0——音频测试全攻略

无论是玩电脑音乐还是玩HIFI，大家一定对权威测试软件RMAA不会陌生，全称为Right Mark Audio Analyzer，从字面上来理解就是“正确打分的音频分析器”。其母公司Symplex也就是俄罗斯最大的IT网站（www．iXBT．com）于2001年在莫斯科注册了Rightnlark网站（www．rightmark．com），注重于发展PC的免费测试软件，至今为止Rightmark旗下已经有CPU、内存、主板、声卡、显卡等测试软件，而其中RMAA这款音频测试软件凭借其易用、

Right Mark Audio Analyzer（RMAA）客观评测所用的软件

这是一款由俄罗斯硬件资讯网站IXBT．com开发的音频硬件测试软件，它能完成许多价格昂贵的专业仪器才能完成的工作。其测试项目有频率响应、信噪比、动态范围、总谐波失真、立体声分离度和互调失真共5项。其中，我们用于判定MP3手机音质的最重要的两项．是频率响应和总谐波失真。

金耳朵用RMAA检验MP3播放器的音质

很多朋友都拥有MP3播放器，音质好坏都靠耳朵听。不是每个玩家都有一对金耳朵，但软件RMAA却可以告诉你一个量化的结果。RMAA全名是“Riht Mark Audio Analyzer”（下载地址：http：//audio.rightmark.org）该软件的工作原理是对所测量的音频信号进行FFT变换，然后把时域信号转交为频域信号，在此基础上进行各种分析，从而判断音质的好坏。

用RMAA测试和设计音箱

声学测试和计算机辅助设计音箱是许多电子爱好者迫切希望做而又难以具备条件去做的，昂贵的仪器设备一般人根本无法拥有或使用。现在好了，用RMAA就可以进行快速的测试和设计!

虚拟音频测试仪RMAA的使用

随着信息产业数字化的发展,广播电台越来越趋向于数字化,使用数字设备录音,使用数字播出设备取代模拟设备,基本上数字信号为主模拟信号为辅。如何测量数字信号的指标,判断数字设备的性能成了当前需解决的问题。文中着重谈了如何使用音频测试软件测试数字信号及设备。

OSH star enterprise pilot scheme——a partnership approach to improve the safety performance of construction industry in Hong Kong SAR

Background: The Occupational Safety and Health Council(OSHC) is committed to improve the safety performance of the high risk construction industry.In the past three years,about 40% of the fatal accidents in the construction industry were related to Renovation,Maintenance,Alteration and Addition(RMAA).Due to the poor safety record,some of the RMAA contractors have difficulty in obtaining the Employees' Compensation Insurance(ECI) cover in the market,or if they could obtain the ECI,the premium rate would be exceedingly high.In view of this,the OSHC,the Labour Department jointly launched"OSH Star Enterprise-Pilot Scheme on Safety Accreditation for the RMAA Industry",which prompts the industry to take practicable safety measures to improve the safety of working environment and reduce occupational injuries.The program also helps the stakeholders and insurers to identify safety-conscious contractors and thereby provide them with a favourable premium rate under the Employees' Compensation Insurance Residual Scheme(ECIRS).Objectives: The OSHC launches the Pilot Scheme to improve the safety performance of the RMAA industry through providing safety training,subsidizing enterprise to purchase safety equipment and providing safety audit.We also use financial incentive to encourage RMAA enterprises to join the Pilot Scheme-for those who are accredited as "OSH Star Enterprise"could receive a premium discount from the ERIRS when obtaining the ECI.The scheme also differentiates those safety-conscious and law-abiding enterprises from the poor performers,which helps the industry and public identifying the RMAA contractors who pay attention to work safety.Methods: The Pilot Scheme targets RMAA enterprises that employ less than 50 employees in Hong Kong.A three-pronged approach is used to improve the safety performance of the RMAA industry: the Pilot Scheme provides(1) financial support for the RMAA contractors to buy a transportable temporary anchor device and full body safety harness and its anchor system;(2) safety training on RMAA work safety and safety & health supervisor course;and(3) safety audit.Results: Enterprises that successfully pass the safety audit and satisfied the Scheme requirements will be accredited as"OSH Star Enterprise",which will be valid for two years.These enterprises can also be upgraded to"OSH Gold Star Enterprise"based on their continuous improvement in safety performance.OSHC will set up a register of OSH-accredited enterprises in RMAA works for reference of the public to facilitate their choosing of accredited contractors.The Employees' Compensation Insurance Residual Scheme Bureau will provide privileged premium rate for enterprises with OSH accreditation."OSH Star Enterprise"could enjoy 40% discounts when joining their insurance scheme.For example,a skilled worker's annual premium can be reduced by about HK $ 36,000.While,the "OSH Gold Star Enterprise"could enjoy 50% discounts when joining their insurance scheme,which means a skilled worker's annual premium can be reduced up to HK $ 45,000.Achievements: This Pilot Scheme offers practical assistance as well as attractive financial incentives for the RMAA industry to improve their safety performance.The Employees'Compensation Insurance Residual Scheme provides premium discounts for enterprises that have a good safety record.It provides incentive for RMAA contractors to actively participate in the Pilot Scheme.The Scheme demonstrates that by providing a safe working environment and appropriate personal protective equipment to workers,the enterprise not only helps to reduce the accident rate of the industry but also receive an economic return.The Pilot Scheme bridges stakeholders of RMAA industry,the government and the insurance industry creating an "all-win"situation.This partnership approach to prevent injuries and accidents in the construction industry could be an effective model for other industries.

漫谈声卡音质

音质，据《辞海》解释为：“传声系统”（如房间电话，录音等声电系统）的声音品质，优良的声电系统要求无干扰，失真等现象。但大多数人对于音质的理解却进入了一个误区，即声音好听，音质就一定好，其实不然……

多普达的"苹果派" 多普达585评测

在机身内部,575和585是完全相同的,都使用了德州仪器OMAP730芯片,都拥有130万像素摄像头,SDRAM和Flash ROM也都分别为32MB和64MB。内置的软件也基本上没有区别。因此,对585的评测,我们将着重评测其独特外观和对第5期575评测进行一些必要的补充。本次评测最为遗憾的是,因为工程样机只装有30万像素摄像头,而正式上市的585将会是百万像素级的可拍照手机。故此摄像头评测只能留待以后补充。585的表面工艺与iPod类似,都有一种牛奶般的质感。与iPod不同的是,585两侧有银灰色的防滑条,正面的功能键和数字健则采用了半透明的塑料键,这让585从正面看上去与索尼爱立信的T628颇有几分相似。585更独特的地方在于其4个圆形快捷按钮--其中3个为媒体播放快捷键--这清楚地表明了585的市场定位--一台时尚、精致的Smartphone、一个操纵便捷的随身娱乐设备。

凤凰涅槃之电脑多媒体音箱(下)

2.功放电路以一个声道为例,运放型的功放IC,其闭环电压增益等于R11和R15的比值或者在此基础上加1,单位是V/V,很多设计中,似乎更多的注意了两个电阻的比值的大小,对二者的具体阻值关注不够。

MP3播放器音质测试

如果你以为MP3播放器的音质都差不多，那可以大错特错了，尽管你会说自己不是“金耳朵”，对音质要求不高，但是我们相信在你听过我们测试中音质评价得分最高和最低的产品之后，你会改变看法的。高坦的MP3播放效果和CD唱片很接近，可是我们发现有的MP3播放器的声音还不如磁带随身听，甚至和收音机差不多。

制作一台高性能的台式声卡

笔者测试音响器材时．用的是RMAA溅试软件和声卡．但限于电脑自带声卡的性能一般．测试结果受到一定影响。而浏览市面上的声卡．模拟输入通道也大多只是个摆设．于是我产生一个念头：使用高性能的ADc和DAC芯片。自己动手制作一个高性能的USB声卡。

用实验板来装配LM4780

今年第5期我刊为广大读者联系了LM4780的样片。虽然LM4780的外围电路形式与大功率运放非常相似，但在业余条件下要想装好不太容易，为此，我们从本期起给广大音响爱好者提供一个交流的平台，就制作中出现的问题，谈自己的体会。本系列的文章包括：用实验板来装配LM4780；如何选择和获得LM4780的外围元件；用单面板做LM4780的印板；给LM4780配一套合适的电源；用RMAA测试你的成果等几个专题，欢迎广大音响爱好者积极参与。