Monday, September 30, 2013

Janice : do you know

This is my old CD from Janice but I like it very much as the vocal is good and the overall Cd is pleasant to listen to. 2006, can't believe time has passed so quickly..

Advice on LS3/5A..


Advice from my friend Ginger in the LS3/5a thread on LS3/5a:

I recommend you buy only the original LS3/5A. I see many LS3/5A for sale in Hong Kong had been tampered or so called modified.
The better way to examine it is to open the cabinets to look into the crossovers. The crossovers will each have the brandname of the manufacturer. For example, when you open a Chartwell cabinet, you should see the crossover with the Chartwell logo.
You will not have chance to look into the crossovers, in this case you should look into the woofers, there is a visable difference between the SP1003 (15 ohm version) and SP 1228 (11 ohm version). 
You are also advised to know the history of different logo used by the manufacturer. Foe example, Rogers have different logo on the grilles, the oldest was made of metal in golden colour and the latest was made of plastic. It will be suspicious to see Rogers metal logo comes with so called White Belly SP 1003 as White Belly are the latest SP1003. Apart from the logos, the cabinet, the back label, T27, the speaker terminal also indicate whether the LS3/5A had been modified before.

For my hifi hobby, I must always thank John (Ginger), Richard (rcwy), Sing, KY and 老野 for all the sharing.....

葬心: 黃鶑鶑

This must be one of my most "expensive" CD as the main purpose is for the first song: 葬心 by 黃鶑鶑. This track is also often used by audiophiles to test their hifi system.. Haha. Actually, there are many other nice songs and recording in this Cd. Highly recommended ...

Ls3/5a 玩家分享

For those who wants to come into the world of LS3/5a can read 阿明's book on LS3/5a or the following review..

Rogers Ls3/5a black badge

I have always hated selling hifi items as you will encounter buyers who come with ridiculously low prices. Since I have found the Rogers Gold badge, I was planning to sell my Black badge and only keep the Chartwell for Singapore use and the Rogers Gold badge for use in Hong Kong.

I really hope the potential buyers knows what they are buying and look at the conditions of the speakers.. 

Perhaps I should just keep the Black badge...haha...

Goodmans Ls3/5a

A pair of Goodmans LS3/5a sold for £2706+190 shipping = £2896 coming to HK$36,350, hitch is very expensive in my opinion. Not sure why?

Rogers LS3/5a Gold Badge

My new Rogers LS3/5a Gold badge have finally arrived Homg Kong after traveling from UK, transit to Paris, Mumbai, Guangzhou and finally Hong Kong.

Even though the wait is a long one, it has been a very exciting wait as the anxieties and build up of expectations are quite a happy experience. 

The conditions of the Gold badge speakers are really nice both in term of cosmetic or sound. The corners of the speakers are still very sharp and even though this is a pair of 1977 speakers, it is still in very nice condition. Of all the pairs of LS3/5a that I have owned, these gold badge is the best followed by the Black badge. My friend KY has reminded me that good condition Ls3/5a is getting harder to find and I am sure I will treasure them dearly. I used to own an earlier Ls3/5a gold tag but I sold them after getting the Tannoy Cantebury, which I have regretted deeply. I must count myself lucky to be able to find an original condition gold tag from Uk.

For those who intend to look for the LS3/5a, my advice is to look for them from UK or from collectors who have bought from UK. Those found in Asia, May ran the danger of changing of parts and modifications. There are many Ls3/5a with the new cabinets! which in my opinion! is totally unacceptable. Moreover, I am a believer that the cabinet conditions cannot be worn out as it may affect the airtight enclosure, which in turn may affect the quality of the sound,..

Rogers LS 3/5a最利害的地方是它的音乐味非常浓郁,在播放人声、Jazz和小型室内乐时,其效果不仅可以乱真,更有令人静静听完后不肯离座的魅力。Enjoy!

Sunday, September 29, 2013

Latest Rogers Gold badge transaction

£2288+£180 shipping = £2468 about HK$30,800

Hifi 2013

My hifi 2013, sept 

Listening to 有空來坐坐:陳果 with Chartwell LS3/5a

I was packing my CD collection this afternoon, while watching Fringe season 5, and I found back this CD produced in 2004.

My son Keith also love this CD especially the part, where the ice was dropped into the glass and the drink was opened and poured... The recording is very good for this CD. Using Ls3/5a for listening the female voice is superb and is truly enjoyable.. Thanks My friend KY for the nice Chartwell LS3/5a..

I am a LS3/5a addict...again...

Saturday, September 28, 2013

Price of Ls3/5a in the 1987

蘇永康: 不想獨自快樂

This is an excellent cd with many good songs and vocal. My favourite is track 11: 越吻越傷心 where  蘇永康duet with 吳國敬 (作曲).. Good vocal and stereo vocal and guitars..

With the Musical Fidelity, I can hear better extension of music and warmer sound and clearer image and sound stage..

Chet Atkins in Hollywood

This is a very good guitar cd by Chet Atkins...

Friday, September 27, 2013

Musical Fidelity x 24

I have always wanted to try the Musical Fidelity X24 k DAC which will enhance the sound of my CDP. Even though this is old tech, but it really enhances the music. There are many newer version of the Musical Fidelity DAC in the market but those are made in Taiwan, and not UK..

I am glad to be back in the hifi a gentle way where I do small twick to enhance the system by  adding weight on top of speakers to diffuse the vibration of the speakers as well as using the X24 plus working on speakers placement.

Talking about speakers placement, I remembered have met up with 定位李 when he came for a hifi home visit me together with John many years ago. However, he didn't teach me about speakers placement.. How sad.. Perhaps I do not know how to "polish shoes"? 

Anyway, I have visited the various web pages teaching people how to work on speakers placement...which is also a fun experience....

I just bought a digital cable for using the Musical Fidelity X 24.

To avoid having too much digital sound, I have used the Maranntz 63 KI C D player + Musical Fidelity X24 together with my Western Electroc CD Isolation transformer..= Fantastic sound!

第一: X-24K能驳接DVD、CD、DAT、MiniDics和数码广播(Broadcast digital)。第二: X-24K可以边接16bit,18bit,20bit和24 bit以及32kHz,44.1kHz,48kHz,88.2kHz和96kHz的讯号。
第三: X-24K采用Burr-Brown 24bit delta-Sigma Converter,是真正的24 bit/96 KHz的科技。
第四: X-24K能自动把16bit,18bit,20bit的讯号转化为24 bit,使音源达臻无比准确的境界。
此外, X-24K设有两个Input(Coaxial和optical兼备),可以衔接两组数码音源(如CD机和DVD机)。因此,对于听CD又看DVD的发烧友而言,买一部 X-24K可以达到左右逢源的妙用。

For some review:

Sheryl Crow : Tuesday night music club

This is Sheryl first album.

From the net:
Tuesday Night Music Club is the debut album from American singer/songwriter Sheryl Crow, released on August 3, 1993. The lead single "Run, Baby, Run" was not particularly successful. However, the album gained attention after the success of the third single, "All I Wanna Do," based on the Wyn Cooper poem "Fun" and co-written by David BaerwaldBill BottrellSheryl Crow, and Kevin Gilbert. The single eventually reached number two on theBillboard Hot 100, propelling the album to number three in the US Billboard 200 album charts, selling over 5.3 million units there as of January 2008.[On the UK Album Chart,Tuesday Night Music Club reached #8 and is certified 2× platinum.

It is listed as one of 1001 Albums You Must Hear Before You Die

Even though the lead single "run baby run" was not particularly successful, it is my favourite!

Adele 21

Woke up early for some Adele music this morning.. Not sure if my neigh hour would love these loud music so early...

Thursday, September 26, 2013

Wednesday, September 25, 2013

陳奕迅: 幸福

This is a 1999 recording from 陳奕迅。

Tuesday, September 24, 2013

Vibb eaters

It is imperative for the sound from your speakers. If you imagine that the treble vibrates with 5-20 kHz, and the baffle on the speaker is having its own life and sometimes vibrates between 400 and 900 Hz, good sound can’t be produced as distortion is introduced. You also loose energy in the base since the power is lost when the speaker box is moving backwards. 

Vibb eaters
What do ‘Vibb eaters’ do? ‘Vibb eaters’ consists largely of copper-based sand and small quantities of precious metal that gives it interesting characteristics regarding magnetism as well as absorbing vibrations and transform them into heat. When you place the ‘Vibb eater’ on your speakers, or on your electronic equipment, the vibrations that come from the speaker box will be absorbed through friction between the copper grains and be transformed into heat. It is easiest to feel this on the speaker. If you place your hand on the speaker you find that it is almost free from vibrations. If you on the other hand put your hand on the ‘Vibb eater’ you will sense a heavy activity.

When it comes to speakers the ‘Vibb eater’ works on three fronts:
Through its weight it gives stability to the speaker box when the membranes move.
The vibrations that are generated in the speaker box are most intense at the top of the speaker where the vibrations can’t get any further. When placing a ‘Vibb eater’ on the speaker, the length of the speaker box is prolonged, so that the critical point where the vibrations are most intense is in the ‘Vibb eater’, which absorbs the energy and transforms it into heat.
The magnetic characteristics make the ‘Vibb eater’ have a positive impact on the magnetic fields.

In summary the treble tones become cleaner, free from overtone distortion of a vibrating baffle. The bass becomes quicker and tighter with a deeper bottom sound. Above all the sound picture is widened which gives you a more precise position in width, depth and altitude. Not least is a calm in the reproduction that you have not experienced before.

‘Vibb eaters’ for electronic equipment have a special sand mixture to optimise the magnetic characteristics. Apart from giving stability to the chassis and absorb vibrations, the ‘Vibb eater’ also neutralises a part of the magnetic field from the electronic equipment. One has to try where it is best to place the ‘Vibb eater’ but usually the best place is closest to the power cable or the transformer.

Monday, September 23, 2013

Blue chips gears..

KY has mentioned that good vintage gears such as the LS3/5a is like the blue true..

Saturday, September 21, 2013

Posts from the net


A Little Legend: BBC LS3/5A

原載於HiFi News & Record Review,1990年3月號
作者: Trevor Butler
翻譯: 阿蜜

很難找到任何一個方盒子,如同BBC LS3/5A一般,能勾起如此多的情緒反應,或是製造出這麼多的迷思與誤解。光是它的名字,就引起了困惑,而實際上它只是單純的遵循了BBC的器材編碼方式。依循此一方式,音箱cabinets最前面的兩個字母以CT代表,分音器filters為FL,而喇叭loudspeakers則為LS。編碼中的3表示此一設計主要是供外製轉播(outside broadcast-OB)所用。如果此一編碼為5,則代表供錄音室廣播用,如LS5/9即是。在斜線後的5則是型號。LS3/5即取代較早的OB喇叭如LS3/1。所以我們可以理解LS3/5是當初開始製造時的編號。編號最後的A則是後來加上去的,用以表明第一次也是唯一一次的設計修正。如果有後續的修改的話,則會以B來標示,但那從未發生,也不太像會發生,其原因後文將述明。
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。

此一喇叭的設計概念,是為因應BBC的某些製作環境:當以耳機監聽並不能令人滿意,而又沒有足夠空間來使用Grade I監聽喇叭時。Grade I監聽喇叭是用來調整廣播節目較具決定性的音調平衡,或麥克風的擺位等。現役的Grade I監聽喇叭是LS5/8與LS5/9。Grade II 監聽器則可用以監聽節目的品質,但音調平衡或麥克風擺位等則一般屬於Grade I喇叭的工作範圍,除非別無選擇。設計者因此體認到:前述情況將需要一種小型的Grade II喇叭,而為達成體積小巧的目的,犧牲部分低頻響應與響度便無可厚非。此種喇叭較可能的使用者為:電視外製轉播車的主控區,這些製作者需要以較正式混音時低的音量做監聽。
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。

當時市面上並沒有現成合適的商業產品,因此BBC設在Kingswood Warren的研究部門就被要求設計一對這樣的喇叭。才不到一個星期,原型機就被做出來,並進行實地測試與評估。之所以能這麼快,是因為LS3/5的設計,是脫胎於一對實驗性喇叭,該喇叭已經在Kingswood被用來做一些音頻比例測試(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。

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年間所使用的的這種模型喇叭,它代表了模製過程(modeling process)的一大進步。雖然它在音質及最大輸入功率方面有其侷限,這種小喇叭的組件卻被認為具有足夠高的水準,能滿足戶外廣播所要求的特殊小型監聽器。因此,這種組合就被稱為LS3/5,並顯示出當初的模型實驗者其實已經獲致很好的成果。
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自行製作了一小批這種喇叭,使用在電視轉播車的控制室中,並提供了令人滿意的效果。而後BBC終於面臨一種狀況:需要邀請外面的廠家在認證許可下製造LS3/5。實際上,Rogers在1974年2月19日發出了一則新聞稿,驕傲的宣稱將在該年4月的SONEX ’74大展中展示這種新喇叭。他們附上了一張照片與一組臨時的規格:25瓦的輸入功率,頻率響應80-20,000Hz +/-3db,或是60-20,000Hz +/-4db。分頻點設在3k Hz,低音單體為110m Plastiflex doped Bextrene 音盆,高音單體為27mm半球型Mylar振膜。定價為一只52英鎊外加營業稅!
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。The price,&52 each plus VAT! 

Alas,though,there were to be early problems。Although the BBC had confidence in the KEF B110 bass unit at the time,when a subsequent batch of in-house LS3/5s was needed it was found that the low and high frequency units had undergone significant changes and a re-design of the speaker would be required before production could resume。
Accordingly,the speaker was passed on to the BBC's Designs Department,then located in Great Portland Street,with a request to modify it so that it would once again be suitable。

當時的問題來自三方面:被改變後的B110單體,以不同於前的方式刺激箱體,導致染色的產生。這染色不僅來自低音單體,也來自音箱; 高音單體則產生出明顯的’唇齒’音(lipsy)。
The trouble was in three areas; the B110 had changed,exciting the cabinet in a different way,producing a coloration both from the LF unit and the cabinet; and the HF unit had developed a pronounced 'lipsy' quality。

In an attempt to ensure that cabinet resonance would not cause problems,the side panels had each been damped with a bituminized pad,and the top and bottom panels likewise,except that two layers were required here。In addition,a PVC edging was applied to the chassis of the LF unit and to de-couple it from the front panel and seal the join。In order to damp the air modes of resonance inside,all internal surfaces were lined with polyurethane foam。The cabinet was sealed to prevent air leaks,which might produce extraneous sounds from the high pressures produced - indeed even the screw holes were made airtight。The cabinet problems were associated with the softwood parana pine fillets which connected the back panel to the front; these had an insufficient impedance and were therefore replaced with beech。The back panel was re-specified from the precious sandwich of spruce to multi-ply birch,thus obviating the voids often associated with spruce。This then became the CT4/11A。

藉著此一修正機會,高音單體的高頻唇齒音也被加以處理。當時認為這個裸露的KEF T27 SP 1032高音單體很容易在工作場所打包綑綁時受到損害,故決定加上一層保護金屬格柵,並在Celestion HF2000單體上找到一個,稍事修改後即可適用。另外T27高音單體的振膜很小,其擴散方向近乎無指向性,故其外圍以一圈固定在前障板上的厚毛氈條加以圍繞,意在防止音箱突起的邊緣干擾造成聲音不連貫(acoustic discontinuity)。而前面網的效果也在設計中被考慮進來,因此聆聽時必須要裝上面網,以避免高音域的不平順。
The opportunity was also taken to sort out the treble lisp of the tweeter。It was felt that this unit,the KEF T27 SP1032,was vulnerable because it was exposed and could easily be damaged during rigging at a venue。It was decided to incorporate a protection grille and a suitable one was found,with some modification,from a Celestion HF2000。The tweeter is surrounded by a thick felt-strip mounted on the baffle in order to prevent acoustic discontinuity presented by the edge of the cabinet setting up an interference pattern,since the T27 radiating surface is small and the radiator nearly Omni-directional。The addition of the protection grille was wholly beneficial as it raised the output at higher frequencies and help cure the lisp。The effect of the Tygan cover on the front was taken into account in the design,and the loudspeaker should always be used with the grille on,to avoid discontinuities in the upper presence region。

Having carried out these changes,the crossover had to be adjusted to compensate and the new type,FL6/23 replaced the original FL6/16。Sporting these alterations the first variant of the LS3/5 was born - the LS3/5A。The 'A; suffix was necessitated because although the LS3/5A sounded similar to the LS3/5,the differences were significant enough for it not to be possible to use a mixed pair for stereo listening。Since only small quantities of the LS3/5 had been built,this did not present much of a problem and only 20 units had to be considered obsolete。

For those not fully acquainted with it,the design is still now very much as it was then,with just a few slight enhancements which came about over the years,as will be explained。

在1977年產生了一些明顯的問題,而幾乎每個夏天,製造者的不良率都會稍稍提高。80年代初期做了一個修正,當時單體懸邊的凹陷(surround-dip)似乎稍微被更動了。解決之道為將負責控制它的分頻共振器(crossover resonator)調整到一較低頻率並更改制振電阻(damping resistor)。任何一個這類的修正都由BBC發佈給當時的製造廠家並併入執照中。當時並對高音單體並聯電容(coupling capacitor)的數值做了一些修正,這是整個平衡調整的一部分。當高音單體的材質更動時,它的’Q’值也跟著變動,並在頻率響應上產生一個輕微的偏斜(tippling)。此一並聯電容影響電路的型態並決定其制振為過度或不足(under or over damped)。為調整高音域的平衡,對FL6/23上一個tapped transformer的輸出做了調整,並且改變並聯電容以維持其分頻點。
There were a few noted difficulties in 1977,and almost every Summer saw the reject rate at the manufacturers rise slightly。The early 1980s saw a change when the surround-dip was seen to have moved slightly。This was resolved when the crossover resonator controlling it was tuned to a lower frequency and the damping resistor changed。Any alteration like this is issued by the BBC to the current manufacturers and is incorporated into their license。There have been also some adjustments to the value of the tweeter coupling capacitor; these are part of the relative balance adjustment。As the material of the tweeter alters,the 'Q' changes and there is a mild 'tippling' of the response。This coupling capacitor affects the shape of the network and decides whether it is under or over damped。To adjust the treble balance,an output from a tapped transformer on the FL6/23 is adjusted,and the coupling capacitor changed to maintain the crossover frequency。

1987年的重大修改已經在專門雜誌中被廣泛報導過了,而這次的變動主要卻來自於製造廠商的要求。經過這許多年以後,授權廠商之一Rogers的Richard Ross解釋道,雖然當時製造LS3/5A使其聽起來與測量起來均符合規格是可行的,且可以被接受;但單體符合容許誤差的良率卻有變動,尤其是低音單體。因為LS3/5A的特殊設計,雖然B110單體符合KEF的規格,剛好卻有一種特點,那就是在這種喇叭設計上最關鍵的部分,此一單體的誤差卻最不穩定。在炎熱的夏天,低音單體的不良率可以從10%到85%。從授權廠商的經濟觀點而言,這是無法被接受的。
The major re-assessment of 1987 was widely reported in the specialist press; but this time the alterations had been requested primarily by the manufacturers。As one of the licensees,Richard Ross of Rogers,explained,over the years,whilst it had been possible to make an LS3/5A which sounded and measured within spec,and which was acceptable,the number of units,in particular the woofers which were within tolerance varied。Because of the particular design of the LS3/5A,the B100s,although being to KEF's standards,happened to have the point where their tolerance was most variable occurring at the most critical point in the speakers design。In hot summers the reject rate of the bass units could be anything from 10 to 85 per cent,and,for the licensees,this was not satisfactory from an economic standpoint。

在授權廠商發現難以製造品質劃一的單元的同時,BBC也有他們自己的問題。在1987年年底,成品品質似乎朝向能被接受的底限飄移。確切的說,它們被發現在1k Hz附近的八度有2db的隆起,而這正是影響聲音平衡的關鍵地帶。之前的LS3/5A在這一頻率通常也稍微隆起,但現在它隆起的程度卻開始使人不悅。必須要強調的是,它仍然可以在Grade II監聽喇叭的要求中運作,但以Grade I的標準而言,就無法被接受。
At the same time as the licensees were finding it difficult to make consistent units,the BBC was encountering their own problems。At the end of 1987 it was noticed that the units were tending to drift towards the limit of acceptability。
Specifically,they were found to be about 2dB up at a octave around 1kHz,a particularly critical area for balance。There had always been a slight lift on the LS3/5A here,but now it started to become objectionable。It should be stressed that the units were still operating within limit for a Grade II monitor,but would have been unacceptable in a Grade I。

The crux of the matter was again the 'surround-dip',the precise frequency of which varies by a few hundred Hertz over time。This had become interactive with the box resonance to the extent that action was needed。A change had to be brought about so that speakers could be manufactured which the BBC would find acceptable,to provide them with a consistent loudspeaker they designed,and wanted。

BBC將這件事知會KEF,而KEF派其”特殊產品部門”(Special Products Division)來做因應。此一問題被追本溯源,發現SP1003 B110所使用的二稀橡膠Neoprene缺乏一致性,為此,一款新的B110因應LS3/5A而設計出來。這次使用一種PVC的懸邊,其材質一致性較高,且對溫度變化較穩定,但是順服度較低。因此一個種新的蛛網狀音圈(spider voice-coil)構造就被用來使這種新單體保持與舊單體一樣的靈敏度,以獲致相同的低頻表現。這就是B110 SP1228單體。分頻器設計通常是一個爭論不休的領域,這當然也發生在LS3/5A上。幾經修改,正如報導所言,但這種喇叭的主要規格與整體聲音平衡卻維持不變。
The BBC referred the matter to KEF,who set their Special Products Division to work。The problem was traced to variations in the consistency of the Neoprene used in the making of the SP1003 B110 and so a new B110 was specifically designed for the LS3/5A。This uses a PVC surround,more consistent and temperature stable than the Neoprene but less compliant。A new spider voice-coil assembly was therefore required to give the new drive the same sensitivity as the older one,in order to achieve the bass performance。This is the B110 SP1228。Crossover design is always a source of great debate and this has certainly been the case with the LS3/5A。Changes have been made,as reported,but the main specification and overall sound balance of the speaker have remained the same。

關於這個主題,與LS3/5A有關的事足以寫成一本書。它的複雜性顯現在它的電路圖中。L1與R1被用來等化軸線上的響應突起與低音單體的頻率特性。而C5,L2與R2這組則用來補償另一個響應凹陷。針對高音單體,L3的作用為一分流指示器(shunt inductor)與自耦變壓器(autotransformer),以便區別靈敏度的等級。C2是用以調整保持分頻點的衡定,而R3則用來避免鈴振(ringing),併同R4與C6以調整高頻端的頻率響應。
A book could be written on this subject as far as the LS3/5A is concerned。The complexity is indicated in the circuit diagram。L1 and R1 are employed to equalize the rising axial response and frequency characteristic of the bass unit,while the group C5,L2,and R2 compensate for a hump in this characteristic。For the tweeter,L3 acts as a shunt inductor and as an autotransformer to allow for differing levels of sensitivity。C2 is adjusted to keep the crossover frequency constant and R3 is there to prevent ringing,with R4 and C6 to adjust the frequency response at the upper end。

SP1228低音單體較先前的B110有著較平順的響應,也因此需要較溫和的分頻等化。於是當時決定:分頻器不能單只是重新設計,以補償驅動單體的改變,而應將新技術也整合進來。基本上這個等化裝置(equalization)與先前相當近似,其線路看起來也差不多。之前的設計使用前面提及的自耦變壓器作為高通濾波器的一部分,且用來以1db為單位調整高音單體的音壓。但是當高音單體的靈敏度越來越穩定(誤差在0。5db以內)時,設計者發現可以改用一個較簡單的衡定阻抗衰減器(constant impedance resistive attenuator),在+/-1db的範圍內以每段0。5db的方式作調整。這個較簡單的等化器(equalization)所帶來的效應之一,就是整體阻抗由原來的正常15歐姆變為現在的11歐姆。
The SP1228 has a considerably smoother response than the older-type B110,and hence needs gentler crossover equalization。It was decided therefore that the crossover could not only be re-designed to compensate for the change to the drive unit,but could also incorporate new technology。In essence the equalization is very much the same with a similar looking circuit。The earlier design used the already mentioned taped auto-transformer as part of the high-pass filter and to adjust the level of the tweeter in 1dB steps,but it was noticed that as the tweeter sensitivity was becoming increasingly consistent (to within 0。5dB),a simpler constant impedance resistive attenuator could be used to give the +/-1dB of adjustment in 0。5dB steps。One consequence of the simpler equalization is that the overall impedance has been reduced from the previous 15ohm nominal to now 11ohm nominal。

KEF analyzed the effect of component tolerances on the overall response and found that by tightening these in the most critical areas an improvement in consistency could be achieved。In previous units it had been possible to obtain a 2dB variation。For example,if the network was +1dB in the critical area and the accompanying drive unit was also +1dB the two compounded。KEF decided that by opting for computer-aided matching,it was possible to nominally select components so that if the network was +1dB a drive unit with a -1DB figure would be chosen to give 0dB overall change。The new crossover is the FL6/38,SP2128/ 

因此,KEF得以提供配對的組件給製造廠家,雖然該公司自己並不完整組裝這種喇叭。目前所有三家授權廠家都使用KEF的配對組件。歸根結底,我們必須要說KEF做得實在很好!BBC交付給他們一只1975年製造的LS3/5A參考標準單元No。6,而他們在1988年製造出的組件與之聽起來如此接近,甚至符合Grade 1的標準,且能在品質更為穩定的狀況下生產。因此LS3/5A的編號就被保留下來。
Therefore KEF was able to offer matched components to the manufacturing licensees even though the company does not manufacture the speaker in its entirety themselves。It so happens that all three current licensees use the KEF matched parts。At the end of a day it has to be said that KEF did a superb job。They were issued with a BBC LS3/5A reference unit (no。6) of 1975 vintage and produced a set of 1988 parts which sounded so similar that they were within Grade I limits,and could be made much more consistently。Hence LS3/5A remains。

Spendor過去都完全自行製造分頻器組件,他們表示如果情況需要,同樣能自行生產。他們現在使用鐵粉電感(勿與純鐵ferrite搞混),且被准許不使用先前的矽-鐵E & I繞線電感(E & I transformer winding)。E & I繞線(laminates)較為昂貴,因此他們也沒放過向KEF購買配對組件的機會。
Spendor used to make their own complete crossover units and say that they could start again if they situation called for it。
They have now adopted the iron-dust inductors,not to be confused with ferrite,and have dispensed with their previous silicon-iron E & I transformer winding。The E & I laminates tend to be more costly,and the opportunity to buy the matched KEF sets was taken。

Rogers多年來都使用各種純鐵與鐵粉電感,因為他們的研究顯示:鑒於在變換器(transformers)中微小的縫隙卻有著高磁場束,而在純鐵(ferrite)中有較大的空隙與許多磁性物質,因此與無線金屬(radio metal)或單向結晶鋼條(grain-orientated strip steel)比起來,這麼做較經濟,且有較佳的磁飽和品質。雖然繞徑較多,且直流阻抗稍微增加,磁飽和的特性卻相當的增強了。Rogers認為以現代的分頻技術,與其製造一個有縫隙的無線金屬扼流圈(radio metal choke),不如較單純的製造一個有2%至3%誤差的鐵粉磁心電感。部分原因是因為這一設計很複雜,而任何可以使事情簡化的機會都不容錯過。
Rogers had for years used various ferrite and iron-dust cores,because their research showed that they were more economical and gave superior saturation qualities compared with the radio metal or grain-orientated strip steel,given that in the transformers there are quite small gaps with quite high fluxes,whereas in the ferrite’s there are big air gaps and a lot of magnetic material。Although there are probably a few more turns and the DC resistance rises slightly,the saturation properties are considerably enhanced。Rogers decided that with modern crossover techniques,it was simpler to make a 2 or 3% tolerance iron-dust core inductors than to make a gapped radio metal choke。This is partly because the design is complicated and any opportunity to make things less so should not be avoided。

It would perhaps have been simpler in the long term for the BBC to have completely re-designed the speaker,and to have produced a LS3/5B,but they did not want nor could they afford this option,since some three and a half thousand of the existing design were in use up and down the country。And design change had to produce similar results and the same response because future models would end up alongside existing ones。Even today,when a batch is taken to a location,it does not matter whether some are from one generation and some from another - they should all be capable of matching as stereo pairs。That in essence is the whole purpose of the design,consistency through production and during use,anywhere。To sum up,then,the recent changes have offered no enhancements in terms of specification,simply a means to provide better consistency in production to maintain the speaker's standard。This is now back on 'median' and so may sound a little different from those latter 'older models' of just pre-Christmas 1987,but will sound the same as earlier production runs。

在修改之後,阻抗稍微的有改變 --這可以由圖中的模式看出來,它反映出Rogers的兩種標準模式。當原本的阻抗為正常值15歐姆,新型號的正常值則接近11歐姆。檢視列線圖表(nomograph),我們可以看到舊款的阻抗在15歐姆,它使用了舊的等化器與舊的低音單體,這單體的阻抗大約是7歐姆。新的低音單體有較低的直流阻抗,但是在配上新的等化器後,二者的曲線形狀非常相近,儘管現在的平均數值較接近11歐姆。這仍舊意味著LS3/5A是由電壓而非電流所驅動,因此擴大機要能有撼動電壓的勁道(swing volts),並且有適當的輸出功率,但不能是低輸出阻抗者。
The impedance has altered slightly post modifications - this can be seen by the modulus shown,reflecting the Rogers' two standard models。Whereas the original was a nominal 15ohms the newer model is nearer to a nominal 11ohms。Looking at the nomograph,we can see the original as 15ohms,using the old equalizer and with the old bass unit which had about a 7ohm resistance。The new bass unit has a lower DC resistance but,with the new equalizer,the curves are very similar in shape,although the average level is now more like 11ohms。This still means that the LS3/5A is voltage rather than current driven and needs an amplifier that will swing volts and produces reasonable power levels,but not into low impedances。

So an LS3/5A circa1977/78 will not in any particular way be better or worse than one from 1983 or now。The consensus of opinion from those who understand balance,is that the system is the same and offers the same qualities as it always has in terms of its tonal characteristics。

進一步說,近期的製品可說更為平順,因為高音的不平坦已經被去除掉了;而在使用新的懸邊之後,染色也被稍為減低,卻還不至於影響音調的平衡,因為對某一特定頻段染色的察覺,其實關係到整個喇叭系統的平衡與等化。因此,比如說在1k Hz附近的音調染色若被減低到某一可查覺的程度,可能會因而強調出其他頻段的染色。
In detail,the latest models are now marginally smoother because irregularities of the high treble have been sorted out,and the coloration has been reduced by a small degree with the new surround,but not so as to affect the tonal balance,because the perception of localized coloration is all part of the balance of the loudspeaker system and its equalization。So if the tonal coloration was reduced to an extent in,say,the 1kHz region where it was noticeable,it could highlight colorations elsewhere。

The new design offers only,in real terms,a better consistency,executed by KEF to maintain the standard。No enhancement in terms of the specification was made although commentators say the loudspeaker now sounds a little better because it is back on the median。Essentially it produces the same sound。This has been backed by tests carried out at the BBC and with manufacturers,with regard to the unit’s stereo capability。

The total number of LS3/5As made since the first license was granted is estimated to be around 60,000 pairs so it is not surprising that a huge interest has been generated around the world。In the BBC the speaker has found many uses from the one-man OB to the control and balance of experimental quadraphonic transmissions from the Promenade Concerts several years ago and in BBC Local Radio Stations,the design provides the main cubicle monitoring。Even so,the design has its fallbacks like the passive and complicated equalizer in the crossover to restore the loss of low frequency caused by the cabinet size and limited cone area。

授權廠家 Licensees 

在BBC設在Chiswick的器材部門(Equipment Department)自行製作了最早一批產品之後,他們核准幾家公司在特許下依合約製造,
The very history of the speaker has interesting connections with licensees who have been permitted to manufacture them。
After early production runs at the BBC's own Equipment Department in Chiswick,the Corporation permitted a number of companies to apply to produce the speakers under license,as it is obliged to do under its Charter。

執照收費被用來補貼當初開發的花費,而非僅是一種以大量生產降低單位成本的手段,而該筆款項由工程部(Director of Engineering)而非BBC企業接收,因為BBC企業有其他由出版與錄音等所得的商業收益。目前有四家廠商有生產執照,但實際上只有兩家在生產。當初任職於BBC研究部門,且參與LS3/5A規劃的H。D。Harwood所創辦的Harbeth,與Rogers,Spendor,Goodmans等廠家都獲權製造。Goodmans實際上已經停止製造,且未在合約到期時重新申請,而Harbeth則尚未開始製造。
The license fee is a means of recouping the original development cost,not purely a way of cutting unit costs by mass-production,and the money is recovered by the Director of Engineering and not BBC Enterprises,the commercial arm of 'Auntie' which has taken over other money making areas like publications and records。Recently as many as four companies had licenses although in essence only two actually had a production line at that time。This situation came about when Harbeth,formed by HD Harwoodd who was working on the LS3/5A at BBC Research Department,was granted a license while Rogers。Spendor and Goodmans were also permitted to manufacture。Goodmans in fact had ceased production and did not re-apply for their license when the renewal time came,and Harbeth had yet to start making any。

另一家授權廠商Spendor,由晚年的Spencer Hughes與當初同在BBC工作的Dudley Harwood合組。他們最初並未申請執照。當時該公司處在工作滿檔的狀況,但是在後續出現生產空檔時,他們也加入申請,因為實際上Mr。Hughes非常瞭解這個設計與要注意的所有相關事項。
Another licensee manufacturer,Spendor,founded by the late Spencer Hughes who had worked with Dudley Harwood at the BBC,did not apply for a license at the first opportunity。The company was then already working to full capacity,but when a 'vacancy' next arose it did apply,encouraged by the fact that Mr。Hughes knew the design and all that would be entailed by association with it。

Rogers were involved almost from the start and now own the Chartwell brand,a company who also previously licensed to make the LS3/5As。The parent company,Swisstone,acquired the defunct Chartwell,a previous competitor,in 1978 having merged with Rogers in 1975。Manufacturing to quantity demands,in 1979 Rogers announced that it had sold its ten thousandth pair and proclaimed LS3/5A the worlds most successful small loudspeaker。With the Rogers total to date standing at 33,534 pairs。

Harbeth是最後獲得授權的廠家,目前由Alan Shaw經營。在所製造的第一批樣品通過BBC驗證後,目前已可合格的正式生產。他們所生產的是經過電腦輔助測試的版本。
The latest company to be permitted to manufacture is Harbeth,now under the control of Alan Shaw。They had samples from their first batch passed by the BBC and are now eligible for full production; all are of the computer-optimized type。
This initial sampling process,a condition of all licensees,is to assure the BBC that their speakers are being made correctly。The licensee selects two units from the initial batch to send to the BBC。One of these is kept by the Corporation as that licensee's working reference,while the other is tweaked so that it matches the BBC's own reference,a unit from the very first in-house batch。This second speaker is then returned to the licensee and becomes the reference for all their subsequent units to be compared with。

Earlier companies to have been licensed by the BBC have not fared as well。It is agreed that the LS3/5A is not an easy product to make properly and must be marketed correctly。Some names have fallen by the wayside because they found the market was not as large as they forecast,and some found it too difficult to make to the BBC's tight tolerances。These problems could be because people expect more than they see for a £250 loudspeaker,and that without the correct marketing,sales are just not realized。

BBC對授權廠商產品的檢驗持續進行,而一些”見不得人的事”(nasties)也被發掘出來。其中一個例個子是:一只送來檢驗的喇叭有著比正常為厚的金屬罩材質,造成了兩個八度音程有1 1/2db的響應凹陷。不用說這只喇叭很快就被退還了!
Names like Audiomaster,who launched their models in April 1976,had a rather short lived license span while RAM never got any units out on the street:they went bankrupt before the production line got underway。Falcon,who were making crossovers for Goodmans,made a batch for ailing RAM company and then found themselves having to distribute the boards directly because RAM were not in any position to pay for them。A flurry of activity was seen from JPW but no quantities to speak of ever materialized。Constant checking of the licensees production is carried out,and there are some tales of 'nasties' being found。There's the case of a unit coming in for evaluation with a thicker than usual grille material causing a two-octave 1 1/2dB dip。Needless to say it was swiftly returned。

Of the three current manufacturers,Spendor says that although a percentage of their production line ends up in the UK,80% of their sales are to the export trade,the areas being mainly Europe,the USA,and the Far East,including Japan and Taiwan。Rogers also export to Japan,Europe,North America,Hong Kong and Singapore,with more sales to Japan than to the United Kingdom even,where,while a quantity go to the BBC,the hi-fi retail outlets get through a fair volume too。Despite the advances of other designs,the LS3/5A remains a reference standard loudspeaker in its class。

謝詞 Acknowledgements

我受助於BBC工程部以確保本文的正確性。在BBC中,T。Somerville與D。E。L。Shorter兩位公認為現有的標準樹立了基礎。而LS3/5A的研發則仰賴研究部門的Messrs H。D。Harwood 與設計部門的M。E。Whatton與R。W。Mills兩位先生。我們對Whatton先生最近過世深表惋惜。
I am indebted to BBC Engineering for ensuring the accuracy of this article。Within the BBC the work of two people,T Somerville and D E L Shorter,must be considered as having laid the foundation for current standards。The particular work on the LS3/5A was carried out by Messrs H D Harwood of Research Department and both M E Whatton and R W Mills of Designs Department。It was with deep regret that we learned of the recent death of Mr。Whatton。


目前Stirling Broadcast还在继续生产经过BBC认证的LS3/5A V2版本,使用的是他们自己的喇叭单体和「超级规格分频器」。对于DIYer来说,也可以买他们家的套件自己回来组装。



Friday, September 20, 2013

Rogers 60th Anniversary Limited edition

The 60th anniversary limited edition set (limited to 50 set for Singapore then) was sold for SGD$4999, around HK$30,000...

Rogers Ls3/5a Gold badge

Rogers Gold badge 

Sometimes, I think I am crazy as my my hifi fever has really gathered its own momentum. Following the Rogers black badge and the Chartwell, I have progressed further by these Gold badge with serial nos 2xxx.

The conditions for these are really superb considering  age..... 1977   : )