Stirling Broadcast (Rogers BBC)

STIRLING BROADCAST (Rogers)- BBC approved LS3/5a, LS3/6 & SB8 Monitor speakers from England
Music in it Truest form - Designers and builders of Loudspeakers in the BBC tradition

After a long history of repairing and servicing LS3/5a's from within both the professional and amateur arenas, Stirling Broadcast became involved in the manufacture of LS3/5a loudspeakers after purchasing and reselling the bankrupt Rogers stock as NOS.

The LS3/5a 'V2' version retains the LS3/5a License from the British Broadcasting Corporation and is suitable as a drop in replacement for any working pair of LS3/5as. Several professional broadcast establishments have already deployed pairs of LS3/5a V2's into production environments.

The newly released SB_88 and highly regarded LS3/6 continues the tradition, again being the only model in the market that is fully BBC licenced 

The roots of Stirling Broadcast are in the resale of Used/Ex-Demo and End-Of-Line Broadcast equipment, expanding into the manufacture a range of furniture suitable for professional broadcast and radio studios.

After a long history of repairing and servicing LS3/5a's from within both the professional and amateur arenas, Stirling Broadcast became involved in the manufacture of LS3/5a loudspeakers after purchasing and reselling the bankrupt Rogers stock as NOS.

Once an LS3/5a License had been obtained from the BBC, Stirling Broadcast commissioned the manufacture of new T27 and B110 drive units from KEF and reintroduced the LS3/5a to the market, to enthusiastic reception. Shortly afterwards Stirling Broadcast began its path of innovation in the LS3/5a world by introducing higher quality crossovers, referred to as 'SuperSpec', and thin-walled, screw-back cabinets modelled after the prototype LS3/5a cabinets and as seen on the 001/002 pair demonstrated at the HiFi News shows of 2001 and 2002.

Following problems and uncertainties with the continuing supply of T27 and B110 drive units Stirling Broadcast have introduced an updated version of the LS3/5a, now known as the V2. The designer, a luminary in the audio industry, has utilised specially prepared SEAS and ScanSpeak drive units with high grade crossovers that accurately mimic the response characteristics of the original versions. Indeed, feedback from professional and domestic customers so far has indicated that Stirling Broadcast has successfully managed to capture the best aspects of both versions of the LS3/5a, combining the faster and more modern sound of the 11 ohm version with the seductive vocal abilities of the 15 ohm version, and adding an improved and extended bass response and greater power handling for good measure.

This 'V2' version retains the LS3/5a License from the British Broadcasting Corporation and is suitable as a drop in replacement for any working pair of LS3/5as. Several professional broadcast establishments have already deployed pairs of LS3/5a V2's into production environments. Foolowing on from this is the new LS3/ which is also fully BBC licenced.

Reviews

Testimonials

Reviews

.....I’ve placed an order for a pair without hesitation.
Ken Kessler 7 Keith Howard

It was an uncanny experience, playing them side-by-side. Far more revealing would be a test in front of a pack of LS3/5A users who were not told that they were hearing a speaker without KEF drivers. Would they be ‘fooled’, if that’s the appropriate word? I have no doubt: the same realistic voices, just as the Beeb requires for on-site monitoring of spoken-word programming. Detail and warmth without a shred of the clinical. The only doubt in my mind? That I was hearing them at their best…because they were so new

Who could have anticipated this even a year ago? One of the most beloved of all loudspeakers, the legendary BBC LS3/5A, was finished. Period. Stalwart fans of the product – Doug Stirling, for example – issued limited runs, but who could imagine that the speaker might suddenly reappear as a commercial venture?

   Well, it has... and it hasn’t. A percentage of the hard-core, fire-breathing purist audience will continue to blather on about ‘It ain’t an LS3/5A if it isn’t 15ohm/doesn’t say Chartwell/doesn’t have BBC badges/doesn’t have KEF drivers/delete as applicable’. That wasn’t going to happen, because neither KEF nor Harbeth have any intention of putting back into production the drivers needed to make the speaker. While the 11ohm, bi-wire crossover could be replicated, and the cabinet and the Tigon grille material sourced to complete the product, the drivers were simply no longer available.

   Many of you might think, ‘Then it ain’t no LS3/5A.’ But let’s not be too hasty: if it looks/walks/sounds/smells like a duck, then it is a duck. And this speaker is an LS3/5A (not a duck), unless you are so masochistically, self-abnegatingly puristic that you can’t allow a little flexibility to return this much-loved speaker to the fold.

   Thank goodness for lateral thinking. Some years ago, a controversial American designer challenged anyone to hear the difference between his outrageous valve amp and anything else they could name, once he’d ‘voiced’ his to sound the same. He was pooh-poohed, but those who thought about it admitted that he was on to something. After all, isn’t fine-tuning a new product the act of ‘voicing’ it? A resistor here, a wire change there?

MADE HERE TOO
So, thought the revivalists, if the drivers no longer exist, why not find substitutes and then voice them so they’re indistinguishable from the originals? Using the talents of LS3/5A wizards Andy Whittle and John Bell, Rogers has done just that. And they did it using European-sourced/specified drivers, in UK-made cabinets. And assembled right here in England.

   In four years’ total secrecy Whittle and Bell laboured hard to recreate the crossover, source the finest cabinets (remember, they had access to the results of the LS3/5A shoot-out we ran some years back, and knew which specific LS3/5A to emulate) and find some Tigon grille material. Which Bell said was crucial: ‘We could not believe what a difference real Tigon made when compared to a substitute. And a grille couldn’t be voiced like a driver.’

   Whittle and Bell talked me through the project. According to Andy, ‘Assembly and construction… we opted for the best. The cabinet and baffle are both birch ply, none of that dead-sounding MDF. They’re made in the UK and the whole speaker is assembled here. This should keep the traditionalists happy.’   Narrowing down the choice of possible drivers they selected two, which they’d prefer not to be named. ‘Let others do all the work if they too want to replicate the LS3/5A. We used a highly-regarded 19mm soft dome tweeter with the usual Beeb phase correction/protection plate. The woofer is EU-sourced, too.’

   According to Bell, the voicing (and, it must be said, a huge investment from Rogers’ parent company) made the entire project feasible. Whittle described it as an ‘Easy brief: to make something that sounded as close as possible to the original. In practice, it was a bit more difficult, despite a number of attempts. Getting a response curve to match the original LS3/5a’s was quite easy, but getting the sound was not, so a number of drive unit combinations were tried until we hit on the woofer that sounded closest to the original B110.’

   Less problematic was the crossover, which Whittle states ‘is more or less identical to the original – same order slopes. The inductors have slightly different values to allow for the differences in the drive units, and there is an extra bit of resistance on the tweeter because the new tweeter is more sensitive than the T27.’

ON THE NAIL
From here on, this is the easiest review I’ve ever had to write: simply put, they nailed it! Imaging was absolutely identical: wide, deep and virtually emulating a point source. Bass had that same, funky bump, but I swear they factored in a trace more control and extension. Maximum SPLs? Measurements may dictate otherwise, but, wholly subjectively, they seemed louder.

 
   It was an uncanny experience, playing them side-by-side. Far more revealing would be a test in front of a pack of LS3/5A users who were not told that they were hearing a speaker without KEF drivers. Would they be ‘fooled’, if that’s the appropriate word? I have no doubt: the same realistic voices, just as the Beeb requires for on-site monitoring of spoken-word programming. Detail and warmth without a shred of the clinical. The only doubt in my mind? That I was hearing them at their best…because they were so new.

LOOSENING UP
Like the original, these will grow sweeter and ‘looser’ with age. Devotees such as Paul Whatton and Peter Roberts genuinely believe a few years’ usage helps. But I’m confident of what I heard, though the review sample might have had only 100 hours on them. Keb’ Mo’s voice had the same textures, presence, character of the mid-1970s Rogers 15ohm model, his Dobro the same twang. Carolyn Hester? Crystal clarity. Aretha? All the power she can muster. Johnny Winter’s guitar? Biting, fast, liquid when it needed to be.

   Then there’s the pricing. Alas, there was a decision to go pan-European, so the speakers cost more than you’d find on eBay. But there is one small consolation: what you’ll be buying will be brand-spanking-new. But the punch line to all of this? The very day I submitted this review, I learned from John Bell that they had sought, and have received, BBC-approval. Or, to put it another way, quack-quack-quack.

VERDICT
Running these in a dozen permutations, against 11 and 15ohm models, single-and bi-wired, with solid-state and valve gear, playing both CD and vinyl, there was an inescapable conclusion: they have not only succeeded in cloning the LS3/5A, they’ve made it go slightly louder and deeper. I can say but one thing: I’ve placed an order for a pair without hesitation.

If the word “great” means anything in speaker design, the new LS3/6 is a great loudspeaker....This speaker seems to me a true realisation of a dream that many audiophiles have held for a long time:
Robert E Greene

the speaker covers the whole range up to 3kHz with a single driver. This means that it has a kind of coherence that escapes multi-way speakers 

The LS3/6 is convincing on its own with orchestral and rock music. It will play quite surprisingly loudly without difficulty, and it has in-room bass extension sufficient to cover the normal orchestral range as well as most rock.

 the midrange itself remains in the top echelon for a combination of clarity , resolution, and neutrality. And perhaps most of all, coherence—there is no crossover like no crossover, and the LS3/6 speaks with one voice over what amounts to almost the whole range of music.

I belong to a chamber orchestra that plays a lot of pure string music. And the real sound was much in evidence here. The feeling of hearing the sound I hear at my rehearsals was considerable, to say the least.

The realism of the piano was most striking, and the beauty of it, too. And the micro-structure of the piano notes, their complex attack and decay and interplay of overtones, was remarkably convincing. 

Textures were all naturally presented and very cleanly articulated. But none of this involved any aggression in the sound at all—it was just detail as it naturally occurs.

the LS3/6s can play loudly, as noted above. They are easily capable of satisfying orchestral levels in a room of moderate size, with dynamic capacity to spare. With well over 100dB levels possible without strain at 2m, I felt no dynamic constraints at all in my 14' by 27' living room. I could blast away if I wanted to, 

it sounds natural and non-aggressive with orchestral music at considerable volumes, allowing closer to close-up live levels than one might tolerate otherwise. 

One of the grand chapters in the history of audio was the BBC research program some decades ago into how to make speakers with a truthful sound. The BBC had the worthy idea that it would be good to know exactly what its broadcasts actually sounded like, and it undertook to develop speakers that would do the job, commercial models not being sufficiently accurate nor reliably identical. The BBC was in effect seeking the absolute sound before there was The Absolute Sound. The most famous speaker to come out of this program was the popular LS3/5a. At least this was the most famous in the U.S., where it joined the Volkswagen as something to show that one was European-with-it. But the best speaker that came out of the BBC program in those days—the late 1960s and early 1970s— was the LS3/6, the BBC version of the speaker marketed to begin with as the Spendor BC-1.
 
The detailed history is a bit convoluted. In summary, Spencer Hughes, who was working in the mid -1960s for the BBC research program, developed vacuum-formed Bextrene cone drivers and designed the BC-1 speaker around one of them as a bass/mid driver. (The company name Spendor comes from Spencer plus Dorothy, his wife’s name.) The BBC refused the speaker at first, this being a time when, in looking for loudness for rock, it was losing its otherwise mostly good sense. (The BC1 was not a large-signal speaker.) But respect for quality prevailed and the BBC decided to offer for license in their LS series their own version of the BC-1, the LS3/6. The LS3/6 was essentially the same speaker as the BC-1. You can find Spencer Hughes’ own description of the history at http://www.cicable.de/pdf/ bc1story.pdf. Long time passing!
 
When TAS started up in 1973, attention was naturally drawn to the BC-1, with HP calling it “the one and only.” On a personal note, I bought a pair of BC-1s not long afterwards—my first really serious speakers, and my reference when I joined the TAS staff.
 
The BC-1 and thus by implication the LS3/6 acquired an almost legendary status. Later speakers from Spendor also earned rave reviews and high reputations. But somewhere in the back of the mind’s ear, to borrow HP’s phrase, the midrange in particular of the BC-1 remained something of a standard—to this day.
 
Now, Stirling Broadcast, well known already for reissuing the LS3/5a, has undertaken to reissue a modern LS3/6. Almost poetically, it asked Derek Hughes, Spencer and Dorothy’s son and a distinguished speaker designer in his own right, auteur in particular of the remarkable Spendor SP1/2, to undertake the design work. And design work was required since the drivers of the original BC-1 are no longer available and have not been for some time. This was more than a touching gesture. Derek Hughes is in a unique position to understand what was involved in making a speaker to match the LS3/6 specifications. And match it it does. The Stirling Broadcast LS3/6, in fact, earned on test by the BBC an official license, all these decades later, as meeting the specifications of the original licensing of LS3/6. (The BBC policy was and is to offer its models under license to any manufacturer who will undertake to produce the speaker as specified.)
 
Of course the question uppermost in mind must be whether this is just a charming exercise in nostalgia, a Proustian remembrance of things past, or whether it is a loudspeaker of excellence and vitality in today’s world. I say with no hesitation at all that it is the latter. No speaker today could be the unprecedented phenomenon that the BC-1/LS3/6 was when it first appeared, redefining as it did what was possible in low coloration for box speakers. But the Stirling Broadcast LS3/6 is a great speaker without question in my mind by contemporary standards, as well as a worthy tribute and successor to the original. (Hereafter, I shall just call the speaker the LS3/6 since historical discussion is now largely concluded.)
 
HOW CAN THIS BE?
 
We live in a world of rapid change and nominal progress, sometimes even real progress. So one has to ask one’s self from the start how can it be that a speaker that is in effect a modernized version of a design from more than forty years ago is still among the best speakers available. How can the LS3/6 compete in today’s world?
 
For one thing, while audio has changed, acoustics is a mature science and has been for some time. Great acoustic ideas of the 1960s are great ideas now. Second, the main change in speaker design, with all due respect to developments since, has been in improvements in driver behavior, and the LS3/6 uses modern drivers. The drivers are proprietary and custom-manufactured to specifications for Stirling for the LS3/6. Stirling is reluctant to reveal what company actually manufactures the drivers and I respected its privacy to the point of not pressing the point. But the bass/mid driver in particular, the heart of the speaker, is a superb one, to the degree that it seems to me really competitive with the Harbeth bass/mid driver, which is to say, with the top of the class. (Indeed, if I had not known that Harbeth’s RADIAL material is proprietary to Harbeth, I would have suspected that this material was used, so similar are the drivers in sonic character to my ears.)
 
It is worth pausing for a moment to appreciate what the seemingly eternal acoustic ideas are that, combined with the superb drivers, contribute to making the LS3/6 a design still among the best of today.
 
First of all, the speaker covers the whole range up to 3kHz with a single driver. This means that it has a kind of coherence that escapes multi-way speakers with crossovers somewhere around 500–600Hz, say. In the LS3/6, the whole range of musical fundamentals and a good portion of the harmonics of most musical notes emanate from a single driver. Of course many two-ways follow this pattern, but the LS3/6 has a large enough (7") driver and box that it is much more convincing in the bass and the lower mids than small two-ways. While for large music to be played really loudly in very large spaces, one might want to add a subwoofer or two, the LS3/6 is convincing on its own with orchestral and rock music. It will play quite surprisingly loudly without difficulty, and it has in-room bass extension sufficient to cover the normal orchestral range as well as most rock.
 
Moreover, the box shape—the classic two cubic foot box, a foot square and two feet high—is tried and true. I always like to hazard a scientific explanation for these things, but I am not really sure of the reason that this particular shape and size work so well, but the fact that they do has come rather emphatically to my attention over many years (the BC-1 itself, the Spendor SP1, the Spendor SP1/2).
 
In addition, the use of two tweeters offers benefits. The LS3/6, like the other related models, has three drivers but two are tweeters, one crossed over to at 3kHz and one much higher, at 13kHz. This idea, which is all but unique to this series of speakers, makes it possible to have a large lower tweeter which is operating with ease down to the crossover point and a smaller higher tweeter which has a wider pattern than if one ran the main tweeter all the way up. Originally, as I understand it, the two-tweeter arrangement arose out of the need to simply cover the whole range cleanly and completely, but in fact there are advantages even in these days when very wide-range tweeters are available.
 
OW THE LS3/6 SOUNDS
 
But if these general principles are worth noting, still in the end the devil is in the details. One could surely make a speaker of this general type that would not have the remarkable sonic quality of the LS3/6. Derek Hughes has done a wonderful job of carrying the unforgettable sound of the original into the modern era. And most wisely he has firmly resisted the idea of modernizing the speaker in the negative sense of making the bass amusically tight and removing the warmth and fullness of the original. While the bass is less loose than my recollection of the Spendor BC- 1, the LS3/6 still gives a warm full sound, indeed, with good pitch definition as well. The LS3/6 will please the appreciators of the low mids/upper bass of the original and at the same time will make new converts among those not coming at it from past glories. Similarly, the LS3/6 remains determinedly not excessive in the top end. Top-end extension there is, but aggression that is all too often the modern style there is not. (Strictly speaking, there is a little perceived roll-off at the truly extreme top, but this is musically inconsequential and perhaps even advantageous in practice.) And the midrange itself remains in the top echelon for a combination of clarity , resolution, and neutrality. And perhaps most of all, coherence—there is no crossover like no crossover, and the LS3/6 speaks with one voice over what amounts to almost the whole range of music.
 
Since one of the strengths of the BC-1 was string sound, I decided to play as my “first impression” the Budapest Festival Orchestra/Fischer recording of Dvorák’s Nocturne for String Orchestra on Philips, one of my current string-sound favorites. Talk about putting a smile on one’s face! This is the kind of music I play myself all the time—I belong to a chamber orchestra that plays a lot of pure string music. And the real sound was much in evidence here. The feeling of hearing the sound I hear at my rehearsals was considerable, to say the least.
 
Next I tried Bis’ masterpiece of piano recording, Freddy Kempf playing Rachmaninoff’s transcription of Kreisler’s Liebesleid. The realism of the piano was most striking, and the beauty of it, too. And the micro-structure of the piano notes, their complex attack and decay and interplay of overtones, was remarkably convincing. Indeed, one could not help feeling that there is some real magic in having a single driver cover so much of the musical range—and cover it so well.
 
On orchestral music, the LS3/6s has both a compelling tonal naturalness and a striking level of what I might call “informativeness.” Often speakers give perceived detail because of an exaggeration of some area of high frequencies. But the LS3/6s offered unusually detailed information about complex music without treble exaggerations. Indeed, this persisted even if I deliberately turned down the treble with an EQ device below its natural, correct level. The LS3/6 really does have, it seems, an intrinsically high level of information-transmission on complex music. Every individual instrumental line in the Rachmaninoff Symphonic Dances (Proarte, Dallas, Mata) and in the Dvorák New World (Delos, New Jersey, Macal) was made extraordinarily clear, as was the reverberation of the individual lines. Things like the separation between say a trumpet call and the hall’s response to it were revealed exceptionally well. Textures were all naturally presented and very cleanly articulated. But none of this involved any aggression in the sound at all—it was just detail as it naturally occurs.
 
Attached to this is an unusual kind of perceived dynamic punch. Speakers seldom exhibit literal dynamic compression until quite high levels are attempted. But things like snare drum strokes come out especially well-defined on the LS3/6. Even at low levels, where literal compression could not be an issue, the LS3/6s give a special articulation that comes across as dynamic excitement. Perhaps this is attached to the fact that the signal is undivided over most of the range, with the sound coming from a single driver. In any case, for what ever reason, the effect is there. This and the sonic impressions of the previous paragraph suggest yet one more time how well the BBC “lossy” cabinet construction idea actually works, a point that tends to escape most contemporary designers, who are enamored of “rigidity” on what often seems a reflexive basis.
 
You can hear the effect I am referring to on that old standby, Opus 3’s Tiden bar gaar, where the drumming and plucking have unusually clean and articulate character and sound unusually “dynamic” for lack of a better word (though dynamics are not what is literally involved), without being over-etched in the least. And comes to that, the (Swedish) words are unusually well articulated as well and the voice has a very natural quality.
 
And the LS3/6s can play loudly, as noted above. They are easily capable of satisfying orchestral levels in a room of moderate size, with dynamic capacity to spare. With well over 100dB levels possible without strain at 2m, I felt no dynamic constraints at all in my 14' by 27' living room. I could blast away if I wanted to, with headroom to spare. With a subwoofer or two, volume capability could be extended even further but for me, adding subs would be for only ultra-deep bass extension, not for the sake of higher levels. The LS3/6 is a much more robust speaker than the original Spendor BC-1 and plays far louder without difficulty—one of the things modern drivers can do better than earlier ones!
 
The LS3/6s deal successfully with the floor interaction in the low midrange and upper bass. They sail down from 300Hz into the 40Hz region with no dip and no weakness, in contrast to the “floor dip,” the hole in response between 100 and 300Hz, that all too many other speakers exhibit. The LS3/6s thus give the orchestra the proper weight, substance, and solidity. And as with the Spendor SP1/2, DSP correction here finds nothing to correct. And this happens with almost any reasonable setup: It is not a matter of inch-by-inch tweaking. This is a design that just works, although, of course, like any speaker it has to be placed reasonably. The proper performance in the 100 to 300Hz region is crucial to the correct perceived balance and feeling of realism and musicality of full-range music. And here you get it. Bravo!
 
Incidentally, while the grilles of the LS3/6 can be popped off without much difficulty, I recommend not doing so. Grilles off brings up 6–7kHz a little and makes the sound less accurate tonally without actually giving any more in the way of real detail. To the extent that the (lower) tweeter is not absolutely smooth, it has a little hint of excess around 6–7 kHz, and to remove the grilles is to bring this to the fore. With the grilles on, much better, indeed excellent, smoothness is attained. And the removal of the grilles exposes edges in a way not, I should think, to advantage in terms of diffraction. Leave them on!
 
I do not have a pair of BC-1s or original LS3/6s in functioning condition. But I do have a pair of Spendor SP1/2s in good order, Derek Hughes’ design from the early 1990s in the same general style—same driver configuration, same box size, itself a lineal descendent of the original BC-1/LS3/6 design. The speakers are similar but the exact balance is a little different, with the SP/2s having a bit more energy in the 1–2kHz octave than the LS3/6. Even within neutrality as commonly understood, there is room for variation! The LS3/6 has a more precise, slightly crisper sound, with a little more perceived definition, the SP1/2 has a perhaps even more precisely correct rendition of instrumental sound and a slightly smoother treble, set at a slightly lower level. A close call to choose between the older SP1/2 and the LS3/6, down to the point where room conditions would make the difference perhaps. Both great speakers, and clearly from the same family! (The current Spendor model called SP1/2R2 is a quite different speaker: )
 
RADIATION PATTERN AND IMAGING
 
When the LS3/6 first appeared, speakers that were close to neutral were a rarity. Nowadays, quite a few speakers offer an essentially flat on-axis direct arrival, though far from all of them do. In this context of speakers that are in general terms flat, additional importance becomes attached to the radiation pattern of the speaker, to how it projects sound into the room and what the resulting in-room sound is like. And of course possibilities abound, ranging from omnidirectional MBLs to the ultra-beamy Sanders 10b electrostatic, to take some obvious extremes. On the corresponding Web sites, you can read what the advocates of each approach have to say. Stereo playback has no real paradigm: stereo sounds weird anechoically, at least as stereo recordings are actually made, and failing that, user’s choice comes into play as to which kind of radiation pattern into a non-anechoic environment (which we all live in anyway!) gives the most satisfying stereo or, for that matter, the most exact tonal character.
 
Here the current LS3/6, like its ancestor, occupies a middle ground but is even so somewhat distinctive. The LS3/6 is, like all boxes, omni in the bass and switches to primarily forward radiation further up. But it becomes a little beamy above 1kHz because of running quite a large (7") bass/mid driver up to a 3kHz crossover point, stable near the axis but rolled off at angles beyond say 45 degrees.
 
On the practical level, this means that the ideal performance is obtained for a centered listener with the speakers aimed directly at the listening position. And for the listener in that ideal position, the radiation pattern has considerable advantages. Whereas with wider-radiating speakers, one is, as it were, running away from 3kHz energy (right around the frequency of maximum hearing sensitivity); with the LS3/6 one is, as it were, trying to get enough of it, since there is something of a droop there in the overall room response.
 
There are theoretical reasons beyond the ken of simple-minded engineering criteria for not having too much 3kHz energy in terms of sonic naturalness (you can find a detailed discussion here: http://www.linkwitzlab.com/xo_eq.htm). And the proof of the pudding is here in the LS3/6—it sounds natural and non-aggressive with orchestral music at considerable volumes, allowing closer to close-up live levels than one might tolerate otherwise. (Three-thousand Hertz off hard walls really sounds yucky when it is loud—not happening here, even if you have hard walls!)
 
Returning to the stereo question as such: The narrowing of the pattern in this range has the apparent effect of enhancing image focus. A wide pattern can generate a sense of “spaciousness”: the threshold for enhancing spaciousness via sidewall reflections is lower by a good bit than the threshold for altering timbre so one can get the spaciousness without altering the basic sound. But this spaciousness is generated at the cost of de-focusing of the individual images. (There is a good bit written round and about how wide uniform radiation makes for good stereo imaging—but this depends on what one means by “good.”)
 
The LS3/6 has very precise image focus. And when big space is actually on the recording rather than being potentially promoted by sidewall reflections, it is admirably presented. Space in the true sense is of course a matter of locating things precisely, not just having some sort of sense of things all over the place—hearing the boundaries of the hall and so on is what real spaciousness is about. And here you get this. Listen for yourself, centered and with the speakers aimed at you. Remarkable stereo, indeed.
 
IN SUM
 
To say that I like and admire the LS3/6 is to understate the case. This speaker seems to me a true  realisation of a dream that many audiophiles have held for a long time: of a dream that many audiophiles have held for a long time: a modern (and available) speaker with the unique virtues of the Spendor BC-1/ BBC LS3/6—the extraordinary articulateness and neutrality in real listening rooms—but without its dynamic limitations. The Stirling LS3/6s delivers the goods, and it is satisfying in musical terms at a very high level. This is a sound that is both attractive in its own right and true to the real sound of music in a way that most speakers do not approach at all. And when one looks at the price, the idea of a wild bargain comes to mind inevitably.
 
Speaker design has changed over the decades since the original LS3/6s appeared. Floorstanders have largely replaced stand- mounted speakers, narrow fronts have largely replaced wider fronts (for no better reason than visual fashion), ever wider radiation patterns have become popular—the list goes on. In some of these senses, the LS3/6 does not look contemporary. But the sound of real music has not changed. And the things that made the original LS3/6 so truthful to the live experience remain as valid today as they were then. If the word “great” means anything in speaker design, the new LS3/6 is a great loudspeaker.
The Ressurection of a Classic
Paul Seydor

"Wow, those things realy sound rich. What are they?”—my wife Daniele upon hearing Stirling Broadcast’s revival of the clasic BBC LS3/5a minimonitor.

....overall respect for what is by any measure a landmark design in the history of audio. Although it’s been well over fifteen years since I’ve owned a pair, they were once one of several valued references and I’ve much enjoyed this recent reunion. To give the little devils their due, that old black magic that I once knew so well still weaves a pretty bewitching spell.  

“Wow, those things realy sound rich. What are they?”—my wife Daniele upon hearing Stirling Broadcast’s revival of the clasic BBC LS3/5a minimonitor. Danielle’s no audiophile, but she knows what she likes. As her reaction to most speaker systems is an understated but devastating, “Can you just hook the Quads back up again, please?” this qualifies as a rave. Not much later our close friend Jennifer stopped by—like Danielle, no audiophile but a serious music lover who also loves my Quads. Same response, even one of the same adjectives: “What a big rich sound!” When a speaker flips the skirts of the two ladies, I pay attention.
 
Originally designed in the mid-seventies by the BBC as a small monitor for vans, control rooms, and other small quarters, the LS3/5a had a remarkable run for well over two decades before production ceased in the late nineties owing to KEF’s no longer finding it financially worthwhile to manufacture the T27 tweeter and B110 midrange/ woofer that formed the nucleus of the design. Although it was never intended for consumer use, audiophiles were not long in discovering its virtues.
 
First and foremost is a midrange of quite extraordinary richness and presence, with an almost palpable thereness, particularly on voices and acoustic instruments. Second is its sheer openness. At the time of its introduction in 1975, only speakers without enclosures (Quads, KLH Nines, Magneplanars) exhibited greater freedom from boxiness. Third is superb imaging and soundstaging. And fourth, rarely remarked upon but noticeable: a subjectively “bigger” presentation than that of most mini-monitors or, to put it another way, less of the miniaturization effect. Soloists, instrumentalists, jazz trios, string quartets, and so forth are projected with a realism that is still rather startling.
 
The reasons for this last, I’d guess, is because the LS3/5a was so cannily designed for its designated purpose that on much music its dynamic and bass limitations pass almost unnoticed, which also obtains in domestic use given a medium-size or smaller room and a not too heavy hand on the volume pot. To be sure, there is virtually no deep bass and midbass is light, but a clever equalization circuit in the crossover that puts a slight boost (2–3dB) in the upper bass around 100–125Hz ensures that the speaker never, ever sounds thin; on the contrary, it is rather warm and full.
 
With the exception of the original Quad ESL, no other speaker, perhaps no other single audio product, has acquired so enthusiastic, focused, and loyal a following, and none so large or vocal a one. As of 1998, when it ceased production, some 100,000 pairs were in circulation, with 3000 pairs sold in its last year alone. The immediate result was that the used price shot up and stayed there, and a groundswell of clamor developed for its return.
 
Doug Stirling’s U.K.-based Stirling Broadcast was for many years involved in servicing LS3/5as and even for a short time manufacturing them under BBC license. When the supply of KEF drivers dried up for good, Stirling began to think seriously about making the LS3/5a anew. The first thing he did was hire Derek Hughes, the son of Spendor’s Spencer Hughes and an accomplished designer in his own right, who has long experience manufacturing the original at Spendor. (Derek is also auteur of the Spendor S3/5, one of the best mini-monitors to follow the LS3/5a.) When Spendor was bought out, Hughes left and landed at Harbeth, where he now works with another of the most talented of current designers, Alan Shaw, designer of the HL P3, another of the best post-LS3/5a minimonitors.
 
The whole story of its development, along with the history of the LS3/5a, is too long to retell here (see sidebar). The gist of it is that while it was possible (though hardly cheap or easy) to duplicate cabinet size, materials, and construction, what was to be done about drivers? Reputed to be a genius with crossovers, Hughes developed a sophisticated network that managed to make the new proprietary drivers, sourced from SEAS and Scan Speak, mimic the response of the original KEFs. But as they’re not KEF originals, honest man that he is, Stirling added a “V2” to his model designation, even though his LS3/5a is fully licensed by the BBC.
 
Drivers aren’t the only issue. Fourteen years after the LS3/5a’s introduction, the BBC discovered that a number of units already in the field were failing to meet spec, while it was getting increasingly difficult for the KEF drivers, the woofer in particular, to be manufactured within acceptable tolerances. The problem was solved with a combination of matching drivers by computer and a new crossover, resulting in among other things an overall impedance drop to 11 ohms from the original 15 and a second pair of binding posts for biwring (thus also providing an easy way to distinguish which side of the dividing line a unit comes from).
 
Like classic car buffs, vintage equipment cultists typically equate older/original with better, and so it goes with the 15-ohm LS3/ 5a, which many believe to be lusher, more romantic, particularly on voices. But U.K. audio writer Ken Kessler, who knows this speaker and its iterations as well as anybody on earth and a lot better than most, arranged a shootout five years ago of ten LS3/5as from all vintages and several important licensees. The winner by a whisper was Harbeth’s, not only an 11-ohm version but from one of the later licensees. Chartwell’s 15-ohm version placed second. Stirling opted for the 11-ohm version, not least because it was both easier to manage and far more reliable in ensuring unit-to unit matching. However, as regards the enclosure, Stirling returned to its origins: the V2’s may be the only cabinets that are an exact copy, including materials and construction methods, of the Kingswood Warren cabinets used for the small number of very early LS3/5as that were manufactured at the BBC’s in-house R&D center, units that have acquired near Arc of the Covenant status among true believers.
 
So, is the Stirling Broadcast LS3/5a V2 a true LS3/5a? The brief Derek Hughes was handed was or should have been impossible, yet the answer has to be a triumphant “Yes!” Even right out of the box the Stirlings are proud descendants of their royal lineage—the tactile midrange, the projected presence, the warm upper bass, the stellar imaging, the deceptively large presentation—they’re all back. One of my longstanding references is “Do Nothing Till You Hear from Me,” from Verve’s Ella Fitzgerald Sings the Duke Ellington Songbook, which I have on both vinyl and CD. Though mono only, this 1956 recording is one of the most beautifully realistic I know. It opens with Ella, holographically present front and center, accompanied only by piano and guitar. At the bridge, Ben Webster’s saxophone takes over, so strong and vibrant that as it expands to fill the room you can actually sense the studio walls. He is followed by Stuff Smith’s languid, soulful violin played in its lower register. The Stirlings really strutted their stuff with this recording, bringing all three performers right into the room in bold, vivid colors.
 
Since it is manufactured under BBC license, theoretically at least the V2 is or should be interchangeable with any other LS3/5a. As it’s been fifteen years since I’ve listened to the originals with any regularity, just to make sure I wasn’t relying on audio memory alone, I borrowed a pair of 15-ohm Spendor units in near-mint condition. While they do not sound identical to the V2s, being smoother, mellower, and less aggressive above 1kHz, they are close enough that I am inclined to agree with Kessler that the principal differences owe to break in. Compare two dynamic speakers identical in every particular except that one is twenty years old, the other brand new, and the differences will be of the same kind and order as what I heard between the Spendor and the Stirling.
 
The V2’s bass response is fractionally more extended with a little better definition, and it can play slightly louder, but it still won’t satisfy anyone who dismisses the original for its shortfalls in these areas. And while I wouldn’t recommend it to music lovers whose main listening is the standard symphonic repertoire, one afternoon I did play Mahler’s Second and was pleasantly surprised by how effectively its gigantic proportions were suggested—suggested, not reproduced.
 
But “improving” the design was not the point. While in their heads all but the most fanatic LS3/5a cultists know the object of their passion is far from perfect, in their hearts they still want it back with all its virtues, flaws, and idiosyncrasies intact. This means that transparency and resolution, while excellent, are not of the first magnitude. It also means that what in my view is the single most controversial aspect of the original’s tonal profile is still with us. Beginning at 200Hz the response gradually rises to a 2dB peak between 1kHz and 1.5kHz, after which it drops precipitously back to the midrange level until about 3.5kHz, where it dips sharply at the crossover and comes back up again. The aural consequence is a subtle lightening of the overall tonal balance and texture, as if everything were pitched slightly higher with a correspondingly slight loss of body in the lower midrange. Accompanying this is a subtle nasality, rather as if vocalists had caught a very mild head cold. Several Sinatra recordings in particular revealed this. Switch to Quad 57s or 63/988s, Spendor’s SP1/2, or some of the current Harbeths, and suddenly Ella’s chest tones are back in their full throatiness, the lower register of Ben Webster’s voluptuous tenor is as fat and fleshy as I know it to be, and Stuff Smith’s violin sounds less like a viola.
 
This response anomaly has been a constant thorn in the LS3/5a’s development. One of the reasons for the crossover redesign in the late eighties is that owing to driver and materials irregularities, that 1kHz–1.5kHz peak was found to be up as much as 6dB in some units, which is certainly unacceptable (see Alan Shaw’s article, cited in the sidebar). I asked Doug Stirling if he and Hughes had considered designing it out entirely. “If I recall correctly we did go down that road with the early prototype, but it immediately lost that LS3/5a sound,” he replied. “We wanted the authentic LS3/5a sound—and this meant ‘warts and all.’ ”
 
At only 2dB, the effects of the peak are for the most part not only relatively benign but for many constitute an attractive coloration that is judged very musical. Indeed, I wonder if it doesn’t account for the speaker’s fabled “magical” presence. That rise would, among its other effects, subtly emphasize the first few harmonics over the fundamentals, which would almost by definition give the presentation a somewhat richer than real character (hence my wife’s and her friend’s reactions). And the presence peak would explain the nasality. Meanwhile, the sharp drop back to level by 1.5kHz keeps anything really nasty from developing in the 2–4kHz range, where even quite small elevations can be unpleasant.
 
One consequence of living with Quads is to make you keenly aware of (not to say impatient with) tonal anomalies. Still, I wouldn’t want my reservations about those in the LS3/5a to obscure my overall respect for what is by any measure a landmark design in the history of audio. Although it’s been well over fifteen years since I’ve owned a pair, they were once one of several valued references and I’ve much enjoyed this recent reunion. To give the little devils their due, that old black magic that I once knew so well still weaves a pretty bewitching spell.

........Paul Seydor - TAS

The things that made the original LS3/6 so truthful to the live experience remain as valid today as they were then. If the word “great” means anything in speaker design, the new LS3/6 is a great loudspeaker.
Robert E. Greene
Talk about putting a smile on one’s face! This is the kind of music I play myself all the time—I belong to a chamber orchestra that plays a lot of pure string music. And the real sound was much in evidence here. The feeling of hearing the sound I hear at my rehearsals was considerable, to say the least.

To say that I like and admire the LS3/6 is to understate the case. This speaker seems to me a true realization of a dream that many audiophiles have held for a long time: a modern (and available) speaker with the unique virtues of the Spendor BC-1/ BBC LS3/6—the extraordinary articulateness and neutrality in real listening rooms—but without its dynamic limitations. 


An Oldie But A Goodie
 
One of the grand chapters in the history of audio was the BBC research program some decades ago into how to make speakers with a truthful sound. The BBC had the worthy idea that it would be good to know exactly what its broadcasts actually sounded like, and it undertook to develop speakers that would do the job, commercial models not being sufficiently accurate nor reliably identical. The BBC was in effect seeking the absolute sound before there was The Absolute Sound.
 
The most famous speaker to come out of this program was the popular LS3/5a. At least this was the most famous in the U.S.,where it joined the Volkswagen as something to show that one was European-with-it. But the best speaker that came out of the BBC program in those days—the late 1960s and early 1970s— was the LS3/6, the BBC version of the speaker marketed to begin with as the Spendor BC-1.
 
The detailed history is a bit convoluted. In summary, Spencer Hughes, who was working in the mid -1960s for the BBC research program, developed vacuum-formed Bextrene cone drivers and designed the BC-1 speaker around one of them as a bass/mid driver. (The company name Spendor comes from Spencer plus Dorothy, his wife’s name.) The BBC refused the speaker at first, this being a time when, in looking for loudness for rock, it was losing its otherwise mostly good sense. (The BC1 was not a large-signal speaker.) But respect for quality prevailed and the BBC decided to offer for license in their LS series their own version of the BC-1, the LS3/6. The LS3/6 was essentially the same speaker as the BC-1. You can find Spencer Hughes’ own description of the history at http://www.cicable.de/pdf/bc1story.pdf. Long time passing! When TAS started up in 1973, attention was naturally drawn to the BC-1, with HP calling it “the one and only.” On a personal note, I bought a pair of BC-1s not long afterwards—my first really serious speakers, and my reference when I joined the TAS staff.
 
The BC-1 and thus by implication the LS3/6 acquired an almost legendary status. Later speakers from Spendor also earned rave reviews and high reputations. But somewhere in the back of the mind’s ear, to borrow HP’s phrase, the midrange in particular of the BC-1 remained something of a standard—to this day.
 
Now, Stirling Broadcast, well known already for reissuing the LS3/5a, has undertaken to reissue a modern LS3/6. Almost poetically, it asked Derek Hughes, Spencer and Dorothy’s son and a distinguished speaker designer in his own right, auteur in particular of the remarkable Spendor SP1/2, to undertake the design work. And design work was required since the drivers
of the original BC-1 are no longer available and have not been for some time. This was more than a touching gesture. Derek Hughes is in a unique position to understand what was involved in making a speaker to match the LS3/6 specifications. And match it it does. The Stirling Broadcast LS3/6, in fact, earned on test by the BBC an official license, all these decades later, as meeting the specifications of the original licensing of LS3/6. (The BBC policy was and is to offer its models under license to any manufacturer who will undertake to produce the speaker as specified.)
 
Of course the question uppermost in mind must be whether this is just a charming exercise in nostalgia, a Proustian remembrance of things past, or whether it is a loudspeaker of excellence and vitality in today’s world. I say with no hesitation at all that it is the latter. No speaker today could be the unprecedented phenomenon that the BC-1/LS3/6 was when it first appeared, redefining as it did what was possible in low coloration for box speakers. But the Stirling Broadcast LS3/6 is a great speaker without question in my mind by contemporary standards, as well as a worthy tribute and successor to the original. (Hereafter, I shall just call the speaker the LS3/6 since historical discussion is now largely concluded.)
 
How Can This Be?
 
We live in a world of rapid change and nominal progress, sometimes even real progress. So one has to ask one’s self from the start how can it be that a speaker that is in effect a modernized version of a design from more than forty years ago is still among the best speakers available. How can the LS3/6 compete in today’s world?
 
For one thing, while audio has changed, acoustics is a mature science and has been for some time. Great acoustic ideas of the 1960s are great ideas now. Second, the main change in speaker design, with all due respect to developments since, has been in improvements in driver be and custom manufactured to specifications for Stirling for the LS3/6. Stirling is reluctant to reveal what company actually manufactures the drivers and I respected its privacy to the point of not pressing the point. But the bass/mid driver in particular, the heart of the speaker, is a superb one, to the degree that it seems to me really competitive with the Harbeth bass/mid driver, which is to say, with the top of the class. (Indeed, if I had not known that Harbeth’s RADIAL material is proprietary to Harbeth, I would have suspected that this material was used, so similar are the drivers in sonic character to my ears.)
 
It is worth pausing for a moment to appreciate what the seemingly eternal acoustic ideas are that, combined with the superb drivers, contribute to making the LS3/6 a design still among the best of today.
 
First of all, the speaker covers the whole range up to 3kHz with a single driver. This means that it has a kind of coherence that escapes multi-way speakers with crossovers somewhere around 500–600Hz, say. In the LS3/6, the whole range of musical fundamentals and a good portion of the harmonics of most musical notes emanate from a single driver. Of course many two-ways follow this pattern, but the LS3/6 has a large enough (7") driver and box that it is much more convincing in the bass and the lower mids than small two-ways. While for large music to be played really loudly in very large spaces, one might want to add a subwoofer or two, the LS3/6 is convincing on its own with orchestral and rock music. It will play quite surprisingly loudly without difficulty, and it has in-room bass extension sufficient to cover the normal orchestral range as well as most rock.
 
Moreover, the box shape—the classic two cubic foot box, a foot square and two feet high—is tried and true. I always like to hazard a scientific explanation for these things, but I am not really sure of the reason that this particular shape and size work so well, but the fact that they do has come rather emphatically to my attention over many years (the BC-1 itself, the Spendor SP1, the Spendor SP1/2).
 
In addition, the use of two tweeters offers benefits. The LS3/6, like the other related models, has three drivers but two
are tweeters, one crossed over to at 3kHz and one much higher, at 13kHz. This idea, which is all but unique to this series of speakers, makes it possible to have a large lower tweeter which is operating with ease down to the crossover point and a smaller higher tweeter which has a wider pattern than if one ran the main tweeter all the way up. Originally, as I understand it, the two-tweeter arrangement arose out of the need to simply cover the whole range cleanly and completely, but in fact there are advantages even in these days when very wide-range tweeters are available.
 
How the LS3/6 Sounds
 
But if these general principles are worth noting, still in the end the devil is in the details. One could surely make a speaker of this general type that would not have the remarkable sonic quality of the LS3/6. Derek Hughes has done a wonderful job of carrying the unforgettable sound of the original into the modern era. And most wisely he has firmly resisted the idea of modernizing the speaker in the negative sense of making the bass amusically tight and removing the warmth and fullness of the original. While the bass is less loose than my recollection of the Spendor BC-1, the LS3/6 still gives a warm full sound, indeed, with good pitch definition as well. The LS3/6 will please the appreciators of the low mids/upper bass of the original and at the same time will make new converts among those not coming at it from past glories. Similarly, the LS3/6 remains determinedly not excessive in the top end. Top-end extension there is, but aggression that is all too often the modern style there is not. (Strictly speaking, there is a little perceived roll-off at the truly extreme top, but this is musically inconsequential and perhaps even advantageous in practice.) And the midrange itself remains in the top echelon for a combination of clarity, resolution, and neutrality. And perhaps most of all, coherence, there is no crossover like no crossover, and the LS3/6 speaks with one voice over what amounts to almost the whole range of music.
 
Since one of the strengths of the BC-1 was string sound, I decided to play as my “first impression” the Budapest Festival
Orchestra/Fischer recording of Dvorák’s Nocturne for String Orchestra on Philips, one of my current string-sound favorites. Talk about putting a smile on one’s face! This is the kind of music I play myself all the time—I belong to a chamber orchestra that plays a lot of pure string music. And the real sound was much in evidence here. The feeling of hearing the sound I hear at my rehearsals was considerable, to say the least.
 
Next I tried Bis’ masterpiece of piano recording, Freddy Kempf playing Rachmaninoff ’s transcription of Kreisler’s
Liebesleid. The realism of the piano was most striking, and the beauty of it, too. And the micro-structure of the piano notes, their complex attack and decay and interplay of overtones, was remarkably convincing. Indeed, one could not help feeling that there is some real magic in having a single driver cover so much of the musical range—and cover it so well.
On orchestral music, the LS3/6s has both a compelling tonal naturalness and a striking level of what I might call “informativeness.” Often speakers give perceived detail because of an exaggeration of some area of high frequencies. But the LS3/6s offered unusually detailed information about complex music without treble exaggerations. Indeed, this persisted even if I deliberately turned down the treble with an EQ device below its natural, correct level. The LS3/6 really does have, it seems, an intrinsically high level of information-transmission on complex music. Every individual instrumental line in the Rachmaninoff Symphonic Dances (Proarte, Dallas, Mata) and in the Dvorák New World (Delos, New Jersey, Macal) was made extraordinarily clear, as was the reverberation of the individual lines. Things like the separation between say a trumpet call and the hall’s response to it were revealed exceptionally well. Textures were all naturally presented and very cleanly articulated. But none of this involved any aggression in the sound at all—it was just detail as it naturally
occurs.
 
Attached to this is an unusual kind of perceived dynamic punch.
 
Speakers seldom exhibit literal dynamic compression until quite high levels are attempted. But things like snare drum strokes come out especially well-defined on the LS3/6. Even at low levels, where literal compression could not be an issue, the LS3/6s give a special articulation that comes across as dynamic excitement. Perhaps this is attached to the fact that the signal is undivided over most of the range, with the sound coming from a single driver. In any case, for what ever reason, the effect is there. This and the sonic impressions of the previous paragraph suggest yet one more time how well the BBC “lossy” cabinet construction idea actually works, a point that tends to escape most contemporary designers, who are enamored of “rigidity” on what often seems a reflexive basis. You can hear the effect I am referring to on that old standby, Opus 3’s Tiden bar gaar, where the drumming and plucking have unusually clean and articulate character and sound unusually “dynamic” for lack of a better word (though dynamics are not what is literally involved), without being over-etched in the least. And comes to that, the (Swedish) words are unusually well articulated as well and the voice has a very natural quality.
 
And the LS3/6s can play loudly, as noted above. They are easily capable of satisfying orchestral levels in a room of moderate size, with dynamic capacity to spare. With well over 100dB levels possible without strain at 2m, I felt no dynamic constraints at all in my 14' by 27' living room. I could blast away if I wanted to, with headroom to spare. With a subwoofer or two, volume capability could be extended even further but for me, adding subs would be for only ultra-deep bass extension, not for the sake of higher levels. The LS3/6 is a much more robust speaker than the original Spendor BC-1 and plays far louder without difficulty—one of the things modern drivers can do better than earlier ones! The LS3/6s deal successfully with the floor interaction in the low midrange and upper bass. They sail down from 300Hz into the 40Hz region with no dip and no weakness, in contrast to the “floor dip,” the hole in response between 100 and 300Hz, that all too many other speakers exhibit. The LS3/6s thus give the orchestra the proper weight, substance, and solidity. And as with the Spendor SP1/2, DSP correction here finds nothing to correct. And this happens with almost any reasonable setup: It is
not a matter of inch-by-inch tweaking. This is a design that just works, although, of course, like any speaker it has to be placed reasonably. The proper performance in the 100 to 300Hz region is crucial to the correct perceived balance and feeling of realism and musicality of full-range music. And here you get it. Bravo!
 
Incidentally, while the grilles of the LS3/6 can be popped off without much difficulty, I recommend not doing so. Grilles
off brings up 6–7kHz a little and makes the sound less accurate tonally without actually giving any more in the way of real detail. To the extent that the (lower) tweeter is not absolutely smooth, it has a little hint of excess around 6–7 kHz, and to remove the grilles is to bring this to the fore. With the grilles on, much better, indeed excellent, smoothness is attained. And the removal of the grilles exposes edges in a way not, I should think, to advantage in terms of diffraction. Leave them on!
 
I do not have a pair of BC-1s or original LS3/6s in functioning condition. But I do have a pair of Spendor SP1/2s in good order, Derek Hughes’ design from the early 1990s in the same general style—same driver configuration, same box size, itself a lineal descendent of the original BC-1/LS3/6 design. The speakers are similar but the exact balance is a little different, with the SP/2s having a bit more energy in the 1–2kHz octave than the LS3/6.
 
Even within neutrality as commonly understood, there is room for variation! The LS3/6 has a more precise, slightly crisper
sound, with a little more perceived definition, the SP1/2 has a perhaps even more precisely correct rendition of instrumental sound and a slightly smoother treble, set at a slightly lower level.
 
A close call to choose between the SP1/2 and the LS3/6, down to the point where room conditions would make the difference perhaps. Both great speakers, and clearly from the same family! (The current Spendor model called SP1/2R2 is a quite different speaker: see Issue 218.)
 
Radiation Pattern and Imaging
 
When the LS3/6 first appeared, speakers that were close to neutral were a rarity. Nowadays, quite a few speakers offer an
essentially flat on-axis direct arrival, though far from all of them do. In this context of speakers that are in general terms flat, additional importance becomes attached to the radiation pattern of the speaker, to how it projects sound into the room and what the resulting in-room sound is like. And of course possibilities abound, ranging from omnidirectional MBLs to the ultra-beamy Sanders 10b electrostatic, to take some obvious extremes. On the corresponding Web sites, you can read what the advocates of each approach have to say. Stereo playback has no real paradigm:
 
stereo sounds weird anechoically, at least as stereo recordings are actually made, and failing that, user’s choice comes into play as to which kind of radiation pattern into a non-anechoic environment (which we all live in anyway!) gives the most satisfying stereo or, for that matter, the most exact tonal character. Here the current LS3/6, like its ancestor, occupies a middle ground but is even so somewhat distinctive. The LS3/6 is, like all boxes, omni in the bass and switches to primarily forward radiation further up. But it becomes a little beamy above 1kHz because of running quite a large (7") bass/mid driver up to a 3kHz crossover point, stable near the axis but rolled off at angles beyond say 45 degrees.
 
On the practical level, this means that the ideal performance is obtained for a centered listener with the speakers aimed directly at the listening position. And for the listener in that ideal position, the radiation pattern has considerable advantages. Whereas with wider-radiating speakers, one is, as it were, running away from 3kHz energy (right around the frequency of maximum hearing sensitivity); with the LS3/6 one is, as it were, trying to get enough of it, since there is something of a droop there in the overall room response.
 
There are theoretical reasons beyond the ken of simple-minded engineering criteria for not having too much 3kHz energy in terms of sonic naturalness. And the proof of the pudding is here in the LS3/6—it sounds natural and non-aggressive with orchestral music at considerable volumes, allowing closer to close-up live levels than one might tolerate otherwise. (Three-thousand Hertz off hard walls really sounds yucky when it is loud—not happening here, even if you have hard walls!)
Returning to the stereo question as such: The narrowing of the pattern in this range has the apparent effect of
enhancing image focus. A wide pattern can generate a sense of “spaciousness”: the threshold for enhancing spaciousness
via sidewall reflections is lower by a good bit than the threshold for altering timbre so one can get the spaciousness
without altering the basic sound. But this spaciousness is generated at the cost of de-focusing of the individual images.
(There is a good bit written round and about how wide uniform radiation makes for good stereo imaging—but this depends on what one means by “good.”)
 
The LS3/6 has very precise image focus. And when big space is actually on the recording rather than being potentially
promoted by sidewall reflections, it is admirably presented. Space in the true sense is of course a matter of locating
things precisely, not just having some sort of sense of things all over the place—hearing the boundaries of the hall and so on is what real spaciousness is about. And here you get this. Listen for yourself, centered and with the speakers aimed at you. Remarkable stereo, indeed.
 
In Sum
 
To say that I like and admire the LS3/6 is to understate the case. This speaker seems to me a true realization of a dream
that many audiophiles have held for a long time: a modern (and available) speaker with the unique virtues of the Spendor BC-1/ BBC LS3/6—the extraordinary articulateness and neutrality in real listening rooms—but without its dynamic limitations. 
 
The Stirling LS3/6s delivers the goods, and it is satisfying in musical terms at a very high level. This is a sound that is both attractive in its own right and true to the real sound of music in a way that most speakers do not approach at all. And when one looks at the price, the idea of a wild bargain comes to mind inevitably.
 
Speaker design has changed over the decades since the original LS3/6s appeared. Floorstanders have largely replaced standmounted speakers, narrow fronts have largely replaced wider fronts (for no better reason than visual fashion), ever wider radiation patterns have become popular—the list goes on. In some of these senses, the LS3/6 does not look contemporary.
 
But the sound of real music has not changed. And the things that made the original LS3/6 so truthful to the live experience remain as valid today as they were then. If the word “great” means anything in speaker design, the new LS3/6 is a great loudspeaker.

.........

Robert E. Greene
Compared with new Harbeth SHL5 I would say that the Stirlings are more "honest" sounding, if slightly less flattering to bad recordings. And I like the Stirling's extra bass weight.

Some info from a recent forum posting.........Harbeth versus Stirling (LS3/6)........

I won't argue with this new Harbeth approach. I would say that the Stirlings are more "honest" sounding, if slightly less flattering to bad recordings.  And I like the Stirling's extra bass weight. 


REG, on his forum, has offered comparative comments between the Stirling and the SHL5+.  He heard them quite a bit while they were being reviewed by another writer for The Absolute Sound who lives near REG.  He likes both speakers, but seems to favor the Stirling more strongly.

Both speakers need subwoofers to cover the bottom octave, if you care to go there.  

Hi  Tom
Thanks for your steer to the Stirling LS 3/6. 

Guildford Audio dropped a pair for sale or return at my home on Tuesday, in rosewood of course, they made my Harbeth C7s sound a bit sickly in comparison.  In short, all I will say for the moment is ‘ Nice one Derek’!

P.S.:  I would also say that the overall tonal realism of both the Stirling LS3/6 and Harbeth M40.1, as I now have those speakers set up, exceeds that of the Gradient Revolution Active which I used in my main basement bunker room system the last couple of years I was in that house

Hi Tom
In you opinion is the Stirling LS3/6 less coloured than the M40 ?Is  the LS3/6 your current best speaker? 
Richard

On 2 Sep 2015, at 20:44, Tom Mallin wrote:
P.P.S.:  See my latest thoughts on the Stirling LS3/6 in this post on REG's forum:
https://groups.yahoo.com/neo/groups/regsaudioforum/conversations/messages/55712 


On Wed, Sep 2, 2015 at 2:21 PM, Tom Mallin wrote: 
Also note that the Stereophile measurements of the Stirling (not sure about the Harbeth) were taken with the grill cloth off.  Both the Stirling and all Harbeths are meant to be heard with the grill cloths on.  Taking them off makes an obvious difference in favor of the dressed condition.  The top end of the Stirling definitely sounds smoother with the grill on; same definitely goes for the Harbeth M40/40.1.

Both these speakers should definitely be listened to with your ears level with the lower, larger tweeter.  The frequency balance is best there, as are other aspects of the reproduction.

On Wed, Sep 2, 2015 at 2:10 PM, Tom Mallin wrote: 
Richard, I heard them at Axpona in Chicago in April.  I thought they sounded excellent, but that the low bass is not quite as prominent as the primary competition, the Stirling LS3/6, which I own.  I also think that the midbass and warmth regions of the Stirling are a bit more prominent.  The comparative frequency response graphs of these two speakers published in Stereophile tell the story in the lower reaches, I think. 

the SB-88 is a very successful take on the classic BBC monitor format which offers the sort of performance we've come to expect from Derek Hughes over the years - true transparency combined with the sort of tonal neutrality that is very rare these days.
Mark Hennessy

REVIEW SUMMARY: But when compared to the LS3/6, might the strong showing from the SB-88 present an unexpected problem for Stirling Broadcast by tempting away prospective purchasers of the LS3/6? Yes, the LS3/6 is a better loudspeaker, as prolonged listening tests prove. But both models are extremely good, and both offer real value for money. If I couldn't afford the LS3/6, then I'd be delighted with the SB-88; they really are that close. I'd advise that you try to audition them both, as ultimately, it'll be the size of your listening room that determines if it's worth streching to the larger LS3/6.

EXTENDED REVIEW: Doug Stirling is perhaps best known for his highly successful reinvention of the LS3/5A, which he developed with expert assistence from no less an authority than Derek Hughes. The BBC-approved "V2" marked the beginning of a lasting partnership between Doug and Derek, of which the SB-88 is the latest offering.

The SB-88

Back in 2011, Stirling released the LS3/6. This is a very successful reinterpretation of the original BC1/LS3/6 design, but obviously this is a large loudspeaker that might not be appropriate for all domestic settings. The new SB-88 is Doug's answer to this obvious discontinuity in his product range, sitting neatly between the LS3/5A V2 and the LS3/6.

Naturally, the design is once again by Derek Hughes. The drive units are straight from the LS3/6, sans the super-tweeter. Of course, the modern tweeter is more than able to cover the top octave with no help from a super-tweeter, but in the case of the LS3/6, the super-tweeter was needed to match the original design - remember that the Celestion HF1300 didn't go much beyond ~13kHz. The result is the classic 8" bass-mid plus 1" tweeter configuration that was so popular - for good reason - before narrow floor standing designs because the norm.

Drive units

The drive units are custom-made by SEAS to Stirling's specification. The polypropylene bass driver has a modified dust cover and a doped diaphragm. The chassis is die-cast aluminium with a very "open" design that maximises airflow and avoids cavity resonances. Overall, it is an extremely fine performer. I'm not sure what modifications are made to the tweeter, but it carries an OEM part number, so you would need to source replacements from Stirling Broadcast directly in the unlikely event of failure. Naturally, should this happen, the complete loudspeaker should be returned for measurement and calibration (as you'd expect, every loudspeaker is measured and auditioned before leaving the factory).

Crossover

The crossover from the LS3/6 has of course been re-worked for this loudspeaker, but has much in common with that network. Very high quality components are used, and the design is necessarily complicated. Minimalist crossovers are rarely feasible in high quality loudspeakers, despite what the Marketing departments might say!

In common with all Stirling Broadcast loudspeakers, "buy-wiring" is provided for via high quality binding posts. Gold plated shorting links are pre-installed - it is worth checking the binding posts are done up tightly from time to time.

Needless to say, as this is a product that is in current production, I'm not planning to reverse-engineer the crossover schematic. This photograph, taken in situ, tells the story sufficiently well.

Construction

The cabinet is slightly simpler than the LS3/6. Yes, it still uses high quality 9mm birch ply (15mm for the baffle), and yes, the panels are damped with the same modern compound that replaces the bitumen-impreganted felt pads of yesteryear. But this cabinet adopts the more usual approach of fixed front and rear panels, with access to the internal components via the bass driver aperture. The so-called "lossy" cabinets, with their screwed on front and rear panels, might have subtle performance benefits, but they seriously increase the complexity - hence cost - of construction. I don't know if lossy cabinets were auditioned during the development of this model, but I'd be very interested to know what the subjective differences might be. I've certainly heard a lot of positive feedback about lossy cabinets from LS3/5A users (all of Doug's LS3/5A cabinets are lossy), but the LS3/5A is well-known for being an extremely tempermental beast!

An obvious thought occurs to me at this point: Doug has left himself with the possibility of introducing lossy cabinets at some point in the future as a premium option. And for that idea, I hereby claim 10% of every one he sells :-)

Anyway, whatever the details, they are clearly of a very high quality - Stirling uses a UK cabinet maker that supplies many of the big names in the UK hi-fi industry, and the fit and finish is first class. Styling is very much in the classic BBC idiom, with just a gently sculpted profile to the grille frame that (literally) takes the hard edge off the functional lines. The grille frame is machined from a single piece of 9mm birch ply.

This brings me to my only criticism of the construction of the SB-88, and the LS3/6 for that matter. The plastic pegs used to retain the grille grip tenaciously, and it is very difficult indeed to remove the grille. Yes, the units were voiced with the grille in place, and since having children, I'm a believer in keeping grilles firmly in situ, but for those who do wish to remove the grilles - and as the baffles are veneered, I can understand why you'd want to - then you will have something of a struggle on your hands. Something like decorating scraper with a wide blade is the ideal tool to assist removal, but be very careful to avoid marking the inside edges of the side panels when you do this. Perhaps with age, the plastic poppers will soften their grip.

Still, if that's the only thing I can find to complain about so far, we're doing OK...

Once the grille is off, you'll see that the woofer is front-mounted - unlike the LS3/6, which has to be rear-mounted like the original - and it sits in a nicely machined recess that leaves it flush with the front edge of the baffle. Of course, the tweeter is similarly countersunk. Both drivers are secured with M4 hex-head machine screws that connect with metal inserts in the baffle, and gaskets ensure an air-tight seal.

Listening tests

My first listening tests were done via my level-matched A-B comparison box, which feeds the four identical power channels in my power amp. This is an excellent way to quickly compare loudspeakers, as the instantaneous click-free transition somehow magnifies differences that you could easily forget in the time it takes you to swap loudspeakers over. For some time now, this has been a standard part of my test regime. After a few hours of listening like this, I then remove the other loudspeakers from the room, and run my amplifier in bridged mode, which adds a lot of headroom. Prolonged listening to one pair of loudspeakers in isolation allows you to really get to know their strengths and weaknesses in a way that might not be apparent in a quick A-B comparison.

Initially, I set the SB-88s up next to the LS3/6s and started playing a selection of well-worn favourites. Switching between the two was very revealing.

I really didn't know what to expect. Of course, Derek Hughes could have delivered whatever type of sound that Doug asked for, but neither Derek or Doug were prepared to comment before I'd had the chance to listen to them. So would they produce the classic "BBC monitor" sound, or would they sound rather more "modern", or "user friendly"? Remember; not everyone is ready for the truth!

Well, happily they went for the former; they sound almost exactly like the LS3/6. Perhaps that's not completely surprising, but having the same drive units and designer doesn't guarantee anything: after all, most of what you hear is the system design

Until I get around to finishing my LS3/6 review, it might be worth expanding a little bit on how these actually sound. Basically, both the SB-88 and the LS3/6 produce a wonderfully neutral midrange that is easily the equal of the best of the designs to emerge from the BBC school of monitor design. But unlike the older designs, you don't have to live with compromises elsewhere in the spectrum - think Spendor BC1 without the problematic bass end!

OK, so there are differences. The midrange is slightly different; there seems to be fractionally less energy in the 2-3kHz region, which makes the sound slightly warmer compared to the LS3/6. Vocals are slightly better on the LS3/6 - the separation between them and the rest of the mix was subtly improved, and it was easier to separate out the individual components of multi-track harmonies. Likewise with massed strings and brass. The SB-88 did these things extremely well, but the LS3/6 just edged it. The treble from both is especially fine; nicely extended, but with no hint of excess or other artefacts. In fact, this comparison usefully demonstrated just how well the super-tweeter is integrated with the main tweeter in the LS3/6.

Both image effortlessly, provided some care is taken with the room layout. Initially, the left SB-88 was slightly behind the left LS3/6, and this caused the stereo image to become very indistinct, with a definite bias to the right channel in the HF. Moving it forward just an inch or two fixed this, and later tests with just the SB-88s in the room improved the imaging once again. Really, there is nothing to fault here - a perfect picture with nothing drawing attention to itself - the loudspeakers simply disappear. Which, of course, is the hallmark of a well-balanced loudspeaker that has low levels of colouration.

The surprising thing is the bass. I would have expected the smaller SB-88 to have noticeably less bass extension, but from an initial listen, that simply wasn't the case. Extended listening revealed that yes, the bass from the LS3/6 is slightly more extended, and marginally smoother, but in my relatively small listening room they were a lot closer than I expected. A quick look at the impedance curve revealed that the ports are tuned to 45Hz in the SB-88 and 40Hz for the LS3/6.

Away from the LS3/6, how do these compare to other loudspeakers? For me, the obvious test is the ATC SCM20SL, which have been my reference for many years. Now, much as I love them, the ATC isn't perfectly flat across the band - they are a trifle forward in the upper midrange, and they are slighly bass-light unless placed near to a rear wall. Of course, the quality of the bass from the sealed box is outstanding, and for me is the reference against which all ported contenders must be assessed. I'm pleased to report that the SB-88 compares extremely well. The sytem has been extremely well tuned, and the port rarely draws attention to itself. With most material that I tried, I really couldn't identify any problems at all - the bass was well extended and there was no sign of "slowness" caused by excessive group delay (something which can be readily identified with my old Rogers LS7s on certain electronic programme material). These (and the LS3/6) have caused me to re-evaluate my stance on ported enclosures - of course, as with any approach, it's all in the implementation.

While the ATC has the edge on midrange resolution, the SB-88 is smoother and easier to listen to while giving up relatively little in terms of transparency - it's most definitely a "monitor-class" loudspeaker. When playing poorer quality recordings, the SB-88 is more forgiving while retaining almost as much insight. In other words, the Stirling is an easier loudspeaker to live with.

Conclusion

Taken in isolation, the SB-88 is a very successful take on the classic BBC monitor format which offers the sort of performance we've come to expect from Derek Hughes over the years - true transparency with no need to resort to the hackneyed treble-lift "trick" to give the false illusion of detail, combined with the sort of tonal neutrality that is very rare these days.

But when compared to the LS3/6, might the strong showing from the SB-88 present an unexpected problem for Stirling Broadcast by tempting away prospective purchasers of the LS3/6? Yes, the LS3/6 is a better loudspeaker, as prolonged listening tests prove. But both models are extremely good, and both offer real value for money. If I couldn't afford the LS3/6, then I'd be delighted with the SB-88; they really are that close. I'd advise that you try to audition them both, as ultimately, it'll be the size of your listening room that determines if it's worth streching to the larger LS3/6.
....….Mark Hennessy

Testimonials

Greetings from Waikanae
Hi Terry
Just a little note to you in regards to the Stirling Broadcast LS3/6 speakers I purchased from you. 
 
They are wonderful indeed, good sounding, articulate, expressive and musically satisfying. They are definitely the best speakers I have  owned, and I have heard and owned a lot in my life.
 
Many thanks for importing these into the country. I hope they are selling well!
 
Kind Regards
Mark Edwards
One very happy Stirling Broadcast LS3/5a owner

Hi Terry,

The Sirling Broadcast BBC LS3/5s are going just great.
Actually they are amazing right from the beginning. 
Once Ive owned the Spendor LS3/5s, bought new pair a few years back and they are fairly disappointing product.
Thank you,

Togo