很难找到任何一个方盒子，如同BBC LS3/5A一般，能勾起如此多的情绪反应，或是製造出这麽多的迷思与误解。光是它的名字，就引起了困惑，而实际上它只是单纯的遵循了BBC的器材编码方式。依循此一方式，音箱cabinets最前面的两个字母以CT代表，分音器filters为FL，而喇叭loudspeakers则为LS。编码中的3表示此一设计主要是供外製转播(outside broadcast-OB)所用。如果此一编码为5，则代表供录音室广播用，如LS5/9即是。在斜线后的5则是型号。LS3/5即取代较早的OB喇叭如LS3/1。所以我们可以理解LS3/5是当初开始製造时的编号。编号最后的A则是后来加上去的，用以表明第一次也是唯一一次的设计修正。如果有后续的修改的话，则会以B来标示，但那从未发生，也不太像会发生，其原因后文将述明。
There can hardly be another single box which as provoked as much emotive comment，or given rise to so many myths and misunderstandings，as the BBC LS3/5A。The very name has caused confusion，but in fact it simply follows the BBC's coded equipment format。In this，cabinets have the prefix 'CT'，filters 'FL'，and loudspeakers 'LS'，hence the first two letters。The figure '3' in the code indicates that the design is primarily for outside broadcast (OB) use。A figure '5' would mean studio broadcasting，as LS5/9。The number '5' after the stroke is the model number，the LS3/5 supplanting previous
OB speakers like the LS3/1。So we arrive at LS3/5 which was the title of the initial model。Later the 'A' was added to indicate the first and only design alteration to the original specification。Any further specification change would result in a 'B'; but that hasn't happened，and isn't likely to，for reasons which will become apparent。
此一喇叭的设计概念，是为因应BBC的某些製作环境：当以耳机监听并不能令人满意，而又没有足够空间来使用Grade I监听喇叭时。Grade I监听喇叭是用来调整广播节目较具决定性的音调平衡，或麦克风的摆位等。现役的Grade I监听喇叭是LS5/8与LS5/9。Grade II 监听器则可用以监听节目的品质，但音调平衡或麦克风摆位等则一般属于Grade I喇叭的工作范围，除非别无选择。设计者因此体认到：前述情况将需要一种小型的Grade II喇叭，而为达成体积小巧的目的，牺牲部分低频响应与响度便无可厚非。此种喇叭较可能的使用者为：电视外製转播车的主控区，这些製作者需要以较正式溷音时低的音量做监听。
The concept of this speaker was to suit those BBC environments where monitoring on headphones was not satisfactory and yet there wasn't sufficient room for a 'Grade I' monitor。A Grade I monitor can be used for critical tonal balancing of programme material，setting of microphone positioning，etc。Current Grade I monitors are the LS5/8 and LS5/9。A grade II monitor may be used for checking the quality of programme，but balance and mic positioning are normally Grade I-checked unless there is no alternative。It was recognized that what would be required was a small Grade II unit with some sacrifice of bass response and loudness reproduction，this being justified for the sake of achieving compactness。The likely users were，for instance，the production control areas of television OB control vans，where there producer needs to listen at a lower level than that used for the actual mixing。
当时市面上并没有现成合适的商业产品，因此BBC设在Kingswood Warren的研究部门就被要求设计一对这样的喇叭。才不到一个星期，原型机就被做出来，并进行实地测试与评估。之所以能这麽快，是因为LS3/5的设计，是脱胎于一对实验性喇叭，该喇叭已经在Kingswood被用来做一些音频比例测试(acoustic scaling test)的初步工作。
There was no suitably available commercial unit，and so the Research Department of the BBC was asked to design one，at its headquarters in Kingswood Warren。Less than a week elapsed between this request and the first prototype being offered for field trials and evaluation。This came about because the LS3/5 was based around an experimental loudspeaker which had been developed for some preliminary work on acoustic scaling tests at Kingswood。
当时是以1/8比例的模型，并在1/8的波长(也就是8倍高的频率)下录音，某些音响技术的优缺点就可以被评估出来，而不必花大钱建构1：1的环境。当然，正因为如此，这也暗示了整个模型的再生过程所使用的器材，从放音机，喇叭，麦克风到录音机，都要能在极高的水准下运作，其所处理的频宽为400Hz到100kHz，以便能正确模彷一般频宽的40Hz到15kHz。
By using one-eighth scale models，and one-eighth wavelengths (IE，8-times frequencies)，recordings can be made by which the merits of particular acoustic techniques can be assessed without the expense of a life-size environment。
Naturally，though，this implies that the entire model reproduction chain，of tape player，loudspeaker，microphone and recorder，must be capable of operating at very high quality with a frequency range of 400Hz to 100kHz，in order to be able to model accurately a typical bandwidth of，say，40Hz to 15kHz。
照片中就是BBC在1972至1980年间所使用的的这种模型喇叭，它代表了模製过程(modeling process)的一大进步。虽然它在音质及最大输入功率方面有其侷限，这种小喇叭的组件却被认为具有足够高的水准，能满足户外广播所要求的特殊小型监听器。因此，这种组合就被称为LS3/5，并显示出当初的模型实验者其实已经获致很好的成果。
Pictured is the model speaker the BBC used from 1972 until 1980，which represented a major step in the modeling process。Although it had its limitations，primarily in terms of its tonal quality and maximum power handling，components of this small loudspeaker were found to be of a sufficiently high quality to help fulfil the demand for the unusually compact monitor needed in outside broadcast use。This was therefore packaged and called the LS3/5 and showed the model experimenters to have achieved good results。
BBC自行製作了一小批这种喇叭，使用在电视转播车的控制室中，并提供了令人满意的效果。而后BBC终于面临一种状况：需要邀请外面的厂家在认证许可下製造LS3/5。实际上，Rogers在1974年2月19日发出了一则新闻稿，骄傲的宣称将在该年4月的SONEX ’74大展中展示这种新喇叭。他们附上了一张照片与一组临时的规格：25瓦的输入功率，频率响应80-20，000Hz /-3db，或是60-20，000Hz /-4db。分频点设在3k Hz，低音单体为110m Plastiflex doped Bextrene 音盆，高音单体为27mm半球型Mylar振膜。定价为一只52英镑外加营业税!
A small number of these units where made in house by the BBC and used in television mobile-control-rooms where they gave satisfactory service。The BBC got to the stage of inviting applications to make the LS3/5 under license by outside manufacturers。Indeed，Rogers issued a press release on 19th February 1974 which proudly announced that they would be exhibiting the new design at SONEX '74，an exhibition to be held that April。They offered a photograph and a provisional specification：25W power handling with /-3dB 80-20，000Hz and /-4dB 60-20，000kHz。Crossover frequency was quoted at 3kHz and the units were a 110mm bass driver with a Plastiflex doped Bextrene cone and a 27mm Mylar dome tweeter。
