Stirling Broadcast LS3/5a V2 Loudspeaker

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Stirling Broadcast LS3/5a V2
Stirling Broadcast LS3/5a V2 Loudspeaker

“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. TAS