Rogers Studio 3 loudspeaker

Back in the early 1970s, the BBC needed a physically unobtrusive, nearfield monitor loudspeaker for use in outside-broadcast trucks. Accordingly, they instructed their design department, which at that time featured such luminaries as Dudley Harwood (the "father" of the polypropylene cone, who went on to found Harbeth) and the late Spencer Hughes (the "father" of the Bextrene cone, who went on to found Spendor), to produce such a model. Thus, not only was what was then probably the finest collection of British speaker-design talent involved in its development, there were no commercial constraints placed on the design. The only limitations were intended to be those arising from the necessarily small enclosure and the absence of the need for a wide dynamic range under close monitoring conditions.

The result of their efforts, the LS3/5a, was licensed to commercial speaker companies for production, the Rogers version appearing in 1975 and remaining in production until early 1993. Other licensees have included Audiomaster (whose designer, Robin Marshall, went on to found Epos), Chartwell, RAM, Goodmans, Spendor, and Harbeth; the last two still manufacture the speaker (footnote 1).

In all that time, the design has been revised just twice. In 1988, the woofer's surround was changed from a springy Neoprene rubber to a more lossy vinyl compound and the crossover was redesigned, not to change the response, but to bring the production response window closer to target and to make the impedance a little less demanding. In 1990 a bi-wiring option was approved by the BBC, provided the performance in single-wired mode met the original specification. (The Harbeth version is only available in traditional single-wired form.)

The 1992 Kinergetics Holdings takeover of KEF, who had supplied both drive-units and assembled crossover boards for the LS3/5a, brought the future of the classic miniature speaker into doubt. Both Rogers and Harbeth introduced identically sized models of their own, therefore, intended to fill the gap left by the '3/5a's imminent demise (footnote 2). This review looks at both those speakers, the Harbeth HL-P3 and the Rogers Studio 3, and compares them with both a 1992 Harbeth-manufactured pair of LS3/5as, and a 1978 pair of Rogers LS3/5as.

Rogers Studio 3
Built in a laminated birch plywood box that appears to be identical to that of the LS3/5a, the Rogers Studio 3 (footnote 3) keeps the older speaker's inset baffle. (Although there appears to be no cabinet bracing other than fillets supporting the baffle, there is an internal layer of polyurethane foam, and the panels are damped with bitumastic sheets.) Mounted on the baffle, however, are completely different drive-units: a 19mm fabric-dome, ferrofluid-cooled tweeter from SEAS, crossed over at 3kHz to a 110mm woofer of Rogers's own manufacture. (The latter is rabbeted into the front of the baffle.) The woofer is constructed on a diecast chassis, and its polypropylene-copolymer cone has a hyperbolic flare. The tweeter's chassis is damped with a thick fiber pad glued to its magnet. Whereas my trusty Boy Scout compass shows the Studio 3 to throw significantly less of a stray field than the LS3/5a, its drive-units are not shielded; you still can't place the speakers close to your TV monitor.

The crossover, built on a printed circuit board attached to the two pairs of Michell terminal posts, features ferrite-cored inductors and mainly plastic-film capacitors. The sole unpolarized electrolytic, in the leg of the woofer's T between the two series coils, is bypassed with a plastic-film cap and has a 1.5 ohm resistor in series to provide a bit of response tailoring. The electrical slopes are third-order, 18dB/octave, with the tweeter padded down by a 3.3 ohm series resistor.

Unlike the LS3/5a—and breaking with tradition—Rogers's chief engineer, Andy Whittle, intends the Studio 3 to be used close to the wall behind it. The spec sheet says, "Maximum distance 6" from rear wall," which will boost the Rogers's in-room bass. The woofer alignment is therefore over-damped; the speaker will sound too lean when used out in a room.

That was certainly my first impression: With the Studio 3s on the 24" stands in the same places in the room where the LS3/5as had sung, the sound was way too lightweight. I moved them back against the record cabinets that line the wall behind them and the bass balance filled out some. However, while I hadn't thought I was playing the speakers particularly loud, my first audition of the Studio 3s ended after 20 minutes with one of the woofers emitting scraping sounds. Audio Influx Fed-Ex'd me a new woofer which I duly installed (footnote 4) and I managed not to repeat the mishap. However, toward the end of the review period, first the other speaker of the pair, then the one I had repaired, developed buzzes when playing certain bass notes. I couldn't find anything internally wrong, but can only conjecture that the layer of foam that covers the crossover board, friction-fit into position, can move and vibrate. Luckily, I had pretty much finished my auditioning by then, but this doesn't instill confidence in Rogers's QA procedure.

The bass warble tones on our Test CD 2 revealed the in-room response to fall off gradually below 80Hz, even with the speakers up against the wall, with the 40Hz 1/3-octave warble tone about the lowest to be reproduced at any kind of useful level. Because my wall is faced with records, I couldn't get the Studio 3s as close to the room boundary as is probably necessary. I would have thought, however, that given the long wavelengths in the bass, a relatively solid array of LPs which themselves were against the wall would have been sufficient to provide the necessary loading.

What low frequencies there were, however, were extremely articulate. The Studio 3 sounded fast, without a trace of the upper-bass bloom of the HL-P3 or LS3/5a. The tightly integrated pat'n'purr of the bass drum and bass guitar on Michael Ruff's Speaking in Melodies (Sheffield Lab CD-35) sounded significantly cleaner than the LS3/5a, which softened all the attacks of this wide-dynamic-range recording. The Studio 3's lower midrange also seemed very clean, the speaker offering excellent clarity and dynamic range. The guitar riffs on Corey Greenberg's Eden from Test CD 2 spoke with an easy facility, for example.

At the other end of the frequency spectrum, the top octave also sounded clean, though there was a trace of sizzle in the mid-treble noticeable on pink noise. This manifested itself as a lispiness on spoken voice and a forwardness to the sound of treble-heavy instruments like cymbals.

This was with the speakers facing straight ahead, which looks right when the speakers are against the wall behind them. Rogers does recommend that the speakers be toed-in so that their axes cross just in front of the listener, however. The effect of this was to reduce the Studio 3's mid-treble emphasis, improving further the degree of palpability on voice (though hi-hat cymbal remained a mite sniffy). Toe the speakers even further in, and the top octave drops too much, making the sound too mellow.

Despite its midrange clarity, the Studio 3 had a little more character than I would have liked, even after the toe-in had been optimized. The piano on the Audiofon Holberg Suite was a bit too clangorous in the upper midrange, while on Marc Cohn's debut album (Atlantic 82178-2) his voice had excellent palpability but reproduced with too much of a nasal "aww" coloration. On naturally balanced orchestral recodings, however, like the superb in-concert Berlioz Symphonie Fantastique from Andrew Davis (BBC Music magazine, Vol.2 No.1, footnote 5), the less stringent imaging demands of the music, the generally clean quality of the Studio 3's midband, and its excellent bass articulation allowed me to largely forget this aspect of its sound.

Despite its excellent clarity, the Studio 3's soundstaging was not particularly good, most probably because its close-wall placement requirement ensures the presence of strong reflections closely spaced in time giving conflicting depth cues. The soundstage-map test on the second Stereophile Test CD revealed the stereo stage to be confined to the region between the speakers, the out-of-phase image positions being reproduced as being tied to the speakers. Though there was obviously more reverberation when Larry Archibald's voice and handclaps were coming from the back of the church in which the recording had been made, the image didn't actually seem to be set much back behind the plane of the speakers. There also appeared to be some suppression of ambient detail. The reverberant glow surrounding the bongos on Marc Cohn's "Ghost Train" seemed less audible compared with the LS3/5a, for example.

I wanted to like the Studio 3 more than I did. While I appreciated its overall clarity and the excellent articulation of its lower registers—areas in which the vintage LS3/5a loses out in a big way—it had a little more upper-midrange character to its sound than I would have liked. It could, of course, be fairly pointed out that the LS3/5a falls short in this region, but I feel that the older design has an imaging specificity and palpability that more than compensate. The Rogers's placement requirements mean that soundstaging, too, is more amorphous than I insist on—though many listeners are not bothered by this. All in all, I think the Studio 3 is a bit expensive for the sound quality it offers. If you live in a small apartment, however, or if domestic demands make it impossible for you to consider free-space locations for your speakers, the Studio 3 might be worth considering.

Footnote 1: Reviews of the Spendor and Rogers LS3/5as were published in Stereophile in Vol.3 No.12, Vol.4 No.1, Vol.7 No.4, and Vol.12 Nos.2 & 3.

Footnote 2: As fate would have it, news of the speaker's demise was premature. KEF intends to continue providing parts, and it is expected that Rogers will resume manufacture of the LS3/5a. The Rogers brandname was recently purchased by Hong Kong–based Wo Kee Hong Holdings, but Rogers research and production remain the responsibility of UK-based Swisstone Electronics, which has owned the name since the late '70s. In addition, as reported by KK last month (p.39), the BBC has licensed production of a new, higher-power minimonitor design, the LS5/12A, to Harbeth and Dynaudio, but reportedly not to Rogers.

Footnote 3: As this review was being prepared, I heard from Michael Zeugin of Audio Influx, Rogers's importer since the mid-'80s, that they will no longer be distributing the line in the US. They will continue to support the brand, however, until the new Rogers International organization has decided what it wants to do.

Footnote 4: When replacing a drive-unit, I tighten the bolts/screws as you would a car-engine cylinder head: by opposite pairs, as evenly as possible, which will avoid asymmetrical stress on the chassis.

Footnote 5: BBC Music magazine, P.O. Box 30628, Tampa, FL 33630-0628. Tel: (800) 284-0200. Back issues cost $9.95, including S&H. Each issue comes with a full-length CD of complete performances from the BBC archives. This Berlioz performance was recorded in Tokyo on May 28, 1993, and is available with the September 1993 issue.