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?