Once upon a time, the BBC conducted a study aimed at predicting the acoustic properties of studios, and to help with this it constructed an 1/8 scale model of its large Maida Vale studio. A shortage of 1/8 scale musicians to fill this model necessitated a loudspeaker be used to simulate the appropriately-scaled acoustic output. Existing studio monitor designs were too big, so a miniature design using a 110mm bextrene-coned main driver in a five-litre cabinet was developed. The end result was the LS3/5, a design expected to have useful output from around 400Hz upwards; in the event, output extended from around 100Hz, and the design was quickly also pressed into service as a speech-monitoring loudspeaker for use in confined spaces, typically the control rooms in outside broadcast vans. Around 20 pairs were built before the driver manufacturer, KEF, changed the specification of the 110mm unit, necessitating a redesign of the LS3/5, dubbed the LS3/5a. The LS3/5a was also taken up by the audio community, largely due to its notable lack of coloration in the crucial midrange, something many other contemporary designs couldn’t live up to.
We need speak no more of this later design; pretty much all that needs saying, and plenty that doesn’t, has already been said.
The LS3/5 is therefore something of a rarity, an ur-LS3/5a known only to a few, until now. Graham Audio however, has recreated the LS3/5, sourcing a new, 110mm bextrene-coned, main driver made by Volt to Graham’s specification and designed to be as close as possible to the original spec of the initial KEF driver. Modern production methods have meant that this driver is far more consistent from sample to sample than the originals, which had a high reject rate at the time. A new tweeter was also sourced, and the crossover tweaked to recreate the LS3/5’s frequency response (which was somewhat flatter than the LS3/5a) as closely as possible. The BBC design principle of using a thin-walled, plywood cabinet, damped to control resonances, has also been carefully followed and the review samples are impeccably finished in a light cherry veneer.
The context above is important, because I don’t think I can review this loudspeaker as an audio product as it’s also so much an historical artefact. This is, at least in part, because Graham Audio’s designer, Derek Hughes (son of Spencer, who participated in the BBC study, and the design of the original) confirmed that they saw little point in joining the ranks of those producing LS3/5a clones, and instead have sought out the particular niche which the LS3/5 will doubtless carve out for itself. Almost as if to emphasise this, Graham Audio recently purchased the long-lost Chartwell brand name. Chartwell was an early manufacturer of BBC designs and its loudspeakers are highly sought after by collectors. Graham Audio plans to use the Chartwell name on LS3/5 designs, to further cement that link with the BBC’s past.
All of which makes it hard to assess the performance of the LS3/5 in context, because there is at once no context and too much context to deal with. Practically no-one has logged time with the LS3/5, so there’s the academic interest of comparing it with the LS3/5a that replaced it. And then there’s cross-referencing it with a surviving LS3/5, a task that is all but impossible. There’s even setting it in among modern designs. As a result, the LS3/5 invites more questions as you investigate it. Is it simply a museum piece? Is it a collector’s item? The more you think about the loudspeaker, the more your head spins about its provenance. In a way, the closest analogy to the LS3/5 is the recreation of Charles Babbage’s Difference Engine in London’s Science Museum. Babbage drew plans to build his mechanical computer in mid 19th Century, but it remained as just plans until 1991. Is this the real thing?
Ultimately though, what does the LS3/5 sound like? The LS3/5 shares many of the great points of the loudspeaker that replaced it, and it also shares many of that loudspeaker’s limitations. The LS3/5 has the trademark midrange beauty and lack of coloration of the later LS3/5a, and, it also has the lack of deep bass and the modest output levels borne of a low-efficiency design with modest power-handling capacity. It’s more a loudspeaker of exceptional vocal clarity and accuracy than dynamic expressiveness and portrayal of changes in energy levels in music.
Voices are, it must be said, beautifully rendered by this design, and I’ve ploughed through my recordings of The Sixteen, The King’s Singers, The Rodolphus Choir, and others, with considerable pleasure. If this is your musical diet, play on. The lack of coloration, the accurate rendition of tonal colour does, there should be little doubt, set something of a benchmark and once you’ve heard how the LS3/5s portray tone, it does show up where otherwise fine loudspeakers fall short of the ideal.
Richard Burton’s narration on The War of the Worlds [Columbia] is entirely natural and correctly-proportioned. This is the voice of a man in the room, no chestiness or over-emphasised upper bass, no larger-than-life presentation, it is easy to see why the BBC prized the speakers that followed for voice monitoring. This also highlights the principle reported difference between the LS3/5 and the LS3/5a – the flatness of the frequency response means you don’t occasionally feel the need to listen to voices like Burton’s off axis!
Moving to orchestral, the waltz from Shostakovich’s Jazz Suite number 2 [HMV classics] was presented as if heard from the back of the hall, but the orchestral colours drawn by Shostakovich were captured very well, as was the contribution of the various parts to the whole. Fauré’s ‘Agnus Dei’ from the Requiem [EMI] was lush, lavish, and luxuriant in the richness of its orchestral and vocal palette, but with this came a loss of subtle dynamic expression, especially at high volumes where the piece sounds overwrought.
Switching now to jazz, it was easy to appreciate Andy Sheppard’s exquisite saxophone tone on ‘Peshwari’ from Learning to Wave [Provocateur Records], which was nicely offset by the rhythm guitar and tabla. However, the impression of interplay between the musicians was less prominent than usual. Perhaps the best expression of the LS3/5 performance comes with the Balanescu Quartet playing Kraftwerk’s ‘Robot’ from Possessed [Mute]. This had a wonderfully rich, woody, string tones and textures, but seemed to lack a sense of communication between the players.
This is to be expected, and shows the LS3/5 is very likely an accurate rendition of perhaps the most influential loudspeaker that almost no-one has ever heard. The LS3/5 comes from a time when a good loudspeaker was all about tonal accuracy and beauty, and dynamic freedom was distinctly out of favour. This was the era of the original Quad Electrostatic and the KEF Celeste. The headline was a flat frequency response, and all else was secondary. The LS3/5 – born out of a miniature loudspeaker put to use in a Liliputian test studio – became a short-lived but pivotal vocal loudspeaker for Outside Broadcast use, and what followed became a legend in audio circles. This is the LS3/5’s context: the link between the evergreen LS3/5a and its drawing board. It’s a recreation of a historic moment in British loudspeaker design.
As a consequence, the LS3/5 is almost beyond criticism, because I think those who use it will never separate it from its ‘recreation of a historic artefact’ context. So, criticising the LS3/5 for not dealing well with a complex, rhythmic and dynamic music signal is a bit like having a dog which can bark the Finnish national anthem, but criticising its diction and intonation. But more than that, it’s like attacking 1970 for being 46 years ago!
I can’t say with any authority how close the LS3/5 reproductions are to the BBC originals, other than to say that Graham Audio is content, and it is clear that considerable trouble has been taken to recreate the design. The inherently flatter frequency response might imply that, had things been different at the time, the BBC would have continued to use LS3/5s and the LS3/5a might not have happened at all. I think the collectors would have still been very happy, and they will lap this up!
TECHNICAL SPECIFICATIONS
- Type: 2-way standmounting/bookshelf design, 5 litre sealed enclosure made from 9mm birch plywood
- Driver complement: One 110mm bextrene main driver; one 19mm dome tweeter
- Crossover frequencies: 3.2kHz, 2nd order 12dB/octave low pass, 3rd order 18dB/octave high pass
- Frequency response: 70Hz–20kHz (±3dB)
- Impedance: 9 Ohms nominal
- Sensitivity: 83dB (2.83V, 1Metre)
- Dimensions (H×W×D): 190 × 300 × 170 mm
- Weight: 5.5Kg/each
- Finishes: Cherry, Rosewood
- Price: £1,650/pair (cherry); £1,800/pair (rosewood)
Manufacturer: Graham Audio Ltd
Tel: +44 (0)1626 361168
Tags: FEATURED
By Steve Dickinson
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