Inventing a solid-state rectifier made from a Tantalum-Lead Alloy, Guy R. Fountain began his audio-related career in 1926, and subsequently founded Tannoy in the early 30s. In 1947, Fountain’s chief engineer, Ronnie H. Rackham, developed the landmark, Dual-Concentric™ driver system, in which “a horn-loaded compression driver was built concentrically with a direct radiator bass unit using a single magnet assembly with two gaps mounted on a heavy cast frame.” (Tannoy Company/History)
In the ensuing years Decca and EMI adopted the Tannoy speakers in their FFRR studio and Abbey Road studios respectively. 1954 marked the company’s entry into the Northern American home audio market with the establishment of Tannoy USA and Tannoy Canada. Tannoy now bases its North American operations solely in Ontario, Canada.
In the 80’s and 90’s, having gained numerous international accolades on its Prestige series of loudspeakers using the patented DC driver technology, the British loudspeaker company earned an especially revered place in the hearts of Japanese audiophiles. In stark contrast to our renowned pursuit of powerful and measurably superior amplifications, our Asian counterparts preferred a predominant sensibility favoring sonic merits and found rewards in embracing SET amplifications. As a result, the Tannoy’s, empowered by the exclusive Dual-Concentric™ driver system with their SET-friendly efficiency, quickly captured the aspirations of the Japanese audiophiles.
Aside from Tannoy, the single-point source loudspeaker technology has also been attempted by companies such as JBL, Altec, Urei, KEF, Pioneer, Diatone and TEAC, in the forms of co-axial or concentric arrangement of tweeter and woofer for covering the entire audible band.
In the company’s publication named The History of the Dual-Concentric™, Tannoy iterated how its DC — center-mounted tweeter within the bass unit — differs from other companies’ methods:
“The wave guide high frequency unit has a smooth acoustic through the center of the low frequency unit without problems due to masking or diffraction. The low frequency unit operates without obstruction, as the cone piston apex is well clear of the high frequency unit. Both units operate in harmony together providing a single point source covering the whole acoustic audio spectrum and in a way that recreates the original sound field better than any other system.”
Rackham designed the Dual-Concentric™ system so that the flare shape of the 15-inch bass unit would continue the flare rate of the high frequency horn. He was also able to avoid the horn coloration rampant in other companies’ horn design by taking advantage of the DC tweeter horn’s low cut-off frequency from its large mouth diameter, and selecting a crossover point of 1kHz, nearly a whole octave above the natural horn lower cut off point, thus relieving the horn from having to labor in a region within which it is known to excite uncontrollable colorations.
According to Tannoy’s White Paper on Dual-Concentric™ technology, modern days’ iteration of the Dual-Concentric™ employs a tulip-like wave-guide in place of a cone’s centerpiece, also situated inside the woofer’s throat and not prone to interaction with the woofer’s radiating surface that Tannoy claims other coaxial designs are. It is, thus, supposedly superior as it is designed to deliver a homogeneous wave pattern mirroring that of live instruments, thus preserving both the harmonic and phasic characteristics of the original recording like no other driver system can.
To prepare potential customers for the sound of its DC technology, Tannoy explains in a paper named Tannoy’s Dual Concentric™ by Definition that:
“An acclimation period is needed when a Dual Concentric™ is first installed in your system, unless you are already in the know. This is due to the inherent blended power characteristic with frequency for a single-source drive unit of this type…Above [1k]Hz, the concentric horn tweeter in the center continues the range precisely, the main cone flare providing a closely matched distribution, thus maintaining smooth on-and off-axis responses.
“Such a power trend has a distinctive sound in the listening room and differs from the commonly-found alternative where the crossover, from a smaller bass/mid unit, is set at around 3kHz, above which point that 90 degree [dispersion] window increases abruptly to almost 180 degrees as the usual 25mm/1-inch dome tweeter takes over. Designers work hard to smooth out the resulting power transition but it’s difficult to wholly disguise this. It may leave more than a trace of nasality and hardness in the sound, and add drama to transients, a bit of extra percussive attack and excitement; but this in reality is an exaggeration. Since nearly all speakers are made this way, we are more or less adjusted to this kind of sound. This is why a truly neutral speaker such as the Quad ESL63 electrostatic can sound “dull” and “lacking attack”
by comparison. Tannoy’s Dual-Concentric™ also falls into this category and listeners may need a little time to appreciate its intrinsic tonal accuracy.”
Magnets used in the DC drivers were “Anisotropic Barium Ferrite”, a material that Tannoy claims to be more efficient than Alnico in power to weight ratio, and with a much higher coercive force to prevent demagnetization under high power or low storage temperatures.
The Churchill also incorporates a, patented, one-inch, internally wired SuperTweeter™ to augment ultra-frequency reproduction of materials from the high bandwidth SACD and DVD-A media.
Basing on no less than 6 published independent research on the significance of ultra-high frequencies, Dr. Paul Mills, Chief Engineer of Tannoy’s Home Audio Division, authored a White Paper on the extent of augmentation that Churchill’s SuperTweeter™ can do for the speaker’s sonic presentation. Succinctly, while we have known that acoustic instruments possess vast and vital overtones beyond human audibility, research has proven that our ears are effective receptacles for processing inaudible ultra-frequencies as well, and our brains do process those ultra-frequency to our benefits. According to the paper, human speech can attain an upward extension of 40k Hz, while a triangle is capable of going beyond 100k Hz.
Interestingly, the White Paper maintains that despite the 44.1k Hz/16-bit standard’s inherently limited bandwidth when compared with SACD and DVD-A, significant amount of high-frequency information is nevertheless present in the medium, and playback of RBCD will also improve with the SuperTweeter™:
“Even with conventional CD sources, the addition of a SuperTweeter™ reduce phase error and improves transient performance significantly below 20kHz. This leads to
increased tonal accuracy at all frequencies, as the harmonics of instruments are not distorted in time.”
Churchill’s embedded SuperTweeter™ is of the top-of-the-line T200, a 25mm 25 micron titanium dome, with 24 carat vapor deposited gold finish and neodymium magnet, internally wired for use with the Churchill. For readers using earlier Dual-Concentric™ models, Tannoy also offers the T100 separately that utilizes the same platform of the T200 in less exotic finishes. A more affordable T50 is also available.
Churchill’s visually prominent front V-Port works supposedly in hand with the trapezoidal cabinet to reduce common mode resonance. Markus explained to me that the V-Port is a rigid structure constructed prior to the Churchill’s cabinet assemblage. Situated at midpoint of the cabinet’s height, the V-Port not only intercepts resonance of the cabinet, it also serves to add additional, overall rigidity to the cabinet, and reducing port velocity and therefore eliminating port turbulence. Thus, Tannoy claims that the V-Port enables the Churchill to producing more accurate bottom-end information.
A panel of shiny gold, user-adjustable crossover output called Custom Shelving Matrix is mounted at the back of the cabinet. Offering 4 adjustment ranges of 300-700Hz, 700 Hz-1k Hz, 1-5k Hz and 5-40k Hz, the Matrix allows an 1 dB increase in all ranges via gold thumbscrews, while a maximum reduction of 3 dB can be selected at “-1 dB”, “-2 dB” and “-3 dB” increments. In using the Matrix, the Owner’s Manual suggests that,
“Use as little shelving as possible in each band. Try not to over compensate. This feature will help reduce some room created anomalies, but will not fix a bad room.”
The speaker terminals are situated at the bottom rear. Tri-wiring is possible from the 3 pairs of banana and spade compatible terminals marked “VHF“ (Very High Frequen-cies), “HF“ and “LF“, with jumpers provided for bi-wiring. The Manual dedicates two large paragraphs to the workings and benefits it offers, while acknowledging the popularity of bi-wiring and how to proceed in bi-wiring.
Moving the sizable Tannoy’s from room to room would not be an easy task, so burn-in took place in the 12 feet wide by 28 feet long listening room. The speakers projected resounding dynamics and acceptable spectral coherency from the first day, and after nearly 80 hours of use plus idling with the amplifier left on most of the time, spectral uniformity solidified with improved bottom-end articulation and dynamic contrasts.
The Dual-Concentric™ midrange/woofer and horn tweeter exhibited a high-degree of directivity, according presentations with audible differences by degrees of toeing-in. Lesser toe-in angles enhanced spaciousness of the event venue at the expense of maximum tonal coherency, and pointing the tweeter to fire directly at the listening position forged the fullest spectral coherency. I adopted the complete toe-in.
Situating each of the Churchill’s 23 inches away to a side wall, 48 inches from the front wall, and eleven feet from center-stage to the listening position effected a seamless top-to-bottom tonality along with an optimal soundstage delineation. Due to the toe-in arrangement, side wall reflections were also utterly eliminated, negating need for side wall acoustic treatment.
The Churchill’s cabinet was impressively solid, and its trapezoidal rear inhibited back wave interference effectively, negating need for the usual tube trap measure at corner behind each speaker. Its multi-coated lacquer finish and the sheer look of the wood-laden cabinet endowed each speaker with the presence of an exquisite furniture.
Large speakers, such as the Churchill’s, are typically designed for use in spaces with generous dimensions. With that said, nearfield experimentations of the Churchill’s revealed the Dual-Concentric™ system to be able to project incredibly consistent tonality from 2 feet to nearly 15 feet away, making them possibly the only monolithic design suitable for regular use in a range of living spaces. Still, using the Churchill’s in a studio-dimension environment mandates careful rear and side wall acoustic treatment to prevent early reflections from interfering with listening. Nearfield listening on other speakers of this size, which usually feature 3 to 4 drivers, is unthinkable.
The Manual’s advice on using the Custom Shelving Matrix leniently proved to be prudent, as a mere 1dB of increase at the lowest cut-over point of 300-700 Hz muddled the lower midrange definition in my listening room, and increasing output at 5-40k Hz brightened the sound unfavorably. Trifling with other frequency ranges also altered sonic coherency unfavorably.
The $20k Churchill WB’s were put into action with 47 Laboratory’s $26,800 4704 PiTracer CD transport and 2 Power Humpty’s, generating digital signals to either Audio Note’s $30k DAC 5 Special or 47 Lab‘s own $7,100, 4705-G Gemini Progression, a new reference DAC and big brother to the 4705 Progression I reviewed in May, 2002. Sony’s SCD-777ES SACD player and the Genesis VI loudspeaker system with its 36k Hz-capable ribbon tweeter provided perspectives on ultra-high frequency playback via the Churchill’s SuperTweeter™.
Amplifications employed in this review included the $15k, 8 Wpc Korean Loth X JI300 Integrated 300B Amplifier, the British Audion’s $16k, 23 Wpc, volume control-equipped Golden Dream Level 6 300B mono-blocks, and Audio Note’s $10k M5 preamplifier driving Linn’s $9,000, Linn Klimax Twin stereo power amplifier. Primary amplification was the M5/KT combo, as it induced the most comprehensive suite of attributes.
Audio Note’s top-line digital cable, the Sogon, provided an incomparable connection between the PiTracer and DAC 5 Special, as well as the 47 Lab Gemini Progression DAC. AN’s Sogon interconnects also carried signals between the DAC and AN’s M5 preamplifier. The AN-Vx silver interconnects linked up the M5 and Klimax Twin. Speaker cable was the AN-SPX silver speaker cable.
In reference to the tri-wiring speaker terminal described under “Technologies”, bi-wired connection to each speaker made use of only one of the two pairs of provided jumpers, bridging between “LF” and “VHF”. Audio Note’s Sogon speaker cables were plugged into the “HF” and “LF” terminals.
Churchill’s instrument portrayal was the most consummating and unforgettable by far towards rendition of size of instruments and scale of ensembles. For example, the Dual-Concentric™ drivers’ top- to bottom-end frequency uniformity was the most superior in the portrait of piano from the hands of Maestro Vladimir Horowitz in his 1985 recording of Mozart’s Piano Concerto No. 23 with Carlo Maria Giulini and Orchestra del Teatro alla Scala (Deutsche Grammophon 474 334-2), endowing the piano with a fullness that only a large-diameter driver could attain.
The speaker’s also demonstrated the advantage of its 15-inch, DC technology towards delineating scale of various instruments, as differing power and volumes of instrument groups were spotlighted realistically in complementing the piano. The most room-filling I’ve experienced, the Churchill DC’s conjured up a more homogeneous wave front , advocating the most communicative presentation to date.
Enforced by the modernistic Linn Klimax Twin, the 15-inch DC’s rendition of Horowitz’s famous dynamic contrasting was also effortlessly lifelike, profoundly suggestive of the live event even during the gentlest pianissimo’s, as the speakers captured the contrasting intricacies and power of the solo instrument as well as collaboration between orchestra and piano. The convincing and expressive transients generated by the Linn/Tannoy interface also reminded me of the competency of the $5k, ELAC CL330 JET minimonitors’ incredibly agile, JET tweeters and the 6-inch, high-excursion woofer, capable of recreating nuances and expeditious transients that surpassed even my reference, the $32k, Celestion SL700.
This 2-disc plus DVD, 100th year anniversary release on the Maestro’s birthday is a must buy at $19.99, and the Maestro’s reading of Etude’s and Mazurka’s were every bit as flamboyant in scale and style as the Mozart concerto.
Tonal depiction was another asset that the Churchill offered in spades.
DG’s recent hybrid SACD release of Mahler: Das Lied Von Der Erde (DG 471 635-2) was testimonial to what the 16-bit/44.1kHz RBCD could achieve. Sounding noticeably more dynamic and spacious than its other pre-DSD releases, this DG recording has some of the least compressed and most natural human singing in the label’s history. Via the Dual-Concentric™, tenor, Michael Schade, and mezzo-soprano, Violeta Urmana, sang with a clarity and spatiality not attained by non-Dual-Concentric™ designs.
While not surpassing the comparably priced Audio Note AN-E SEC Silver‘s in dimensionality and localization specificity, the Tannoy’s, by way of the 47 Lab PiTracer transport and Gemini DAC, aptly conveyed changes in tonalities that liberated a world of complex motions and permutations released by the singers. Exhibiting the most compliant phasic behavior I’ve experienced, the Dual-Concentric™’s rendition of the human voices were rid of the phase shifts inherent in all other multi-driver designs, regardless how infrequent and miniscule those occurrence were. The level of listener concentration this Tannoy advantage induces cannot be overstated.
The delicacy and evocation of the vibrato were two other aspects meticulously portrayed by the Churchill‘s. In portraying the vocalists against a backdrop of the 100+ ensemble, the speakers not only maintained discerning dynamic balance between the singers and the orchestra; but were also especially conducive towards presenting minute vocalization cues onstage that were otherwise summarily buried at times via other speakers. Fans of opera and oratorios alike would welcome the Tannoy methodology undoubtedly.
This ability of preserving phasic characteristics of the original recording also proved indispensable in the music-making by the jazz trio of Tsuyoshi Yamamoto (piano), Ken Kaneko (bass) and Toshio Osumi (drums), superlatively recorded by Winston Ma of First Impression Music (Autumn in Seattle, FIM SACD 040). Serene and sonorous, what could oftentimes be rendered as rather quarrelsome and even non-involving by other speakers has become supremely enticing by the Tannoy‘s.
Via this jazz hybrid SACD, particularly tracks like “Raindrops Keep Falling On My Head”, the delicious, 9-minute long “Misty” and “No Problem”, the Dual-Concentric™’s spontaneity was sweepingly displayed. It’s rhythmic drive competency was at least equivalent to competition sporting larger, panel-type radiating areas and dynamic designs with columns of drivers; but the single-point source, DC methodology conjured up the most solitary tonality, that when asked to portray intimately spaced instruments as featured on this CD, forged a most pulsating experience.
Subjectively, the most defining moment arrived when Brahms’ Symphony No. 1 (DG 453-097-2) was performed by the Churchill’s, in which the pressing yet solemn opening of the 1st Movement commenced with an immensity befitting not only the vision of the conductor; but surely also that of the composer as well. In perhaps the most prominent display of its claim to excellence, the Dual-Concentric™‘s projected the rolling of a most dimensional bass drum in compliment of the stirring, sweeping strings‘ breathtaking proclamation. Wholeness of the orchestra’s unifying forces had never been rendered more spectacularly.
Conductor Herbert von Karajan’s artistry and vision of the monumental score underscores an unrelenting discipline in performance, showing stark contrast against other conductors of stature, many of whose reputed aspirations towards liberal interpretations and sensationalism negate fresh insights in repeated listening. Von Karajan’s approach bestows a multiplicity of interpretative inspirations upon the listener.
Berlin Philharmonic’s incomparable contribution to the overwhelming experience by way of its masterful uniformity was notably indispensable.
Other Amplification Consideration
In driving the 95 dB/8 Ohm Churchill’s, the $15k, Loth X JI300 Integrated 300B Amplifier sounded vastly more powerful than its claimed 8 Wpc of output, imparting vivid tonalities, thus more prominent presence, towards depiction of acoustic instruments than that accorded by the M5/KT amplification.
While not on the same par with the AN/Linn combo in the areas of dynamics and scale, the JI300 was decidedly more complimentary of the Dual-Concentric™’s ability to construct coherent and colossal tonalities. In fact, the partnership possessed a sound that was extremely inviting and most magical at medium listening level, so much so that the Churchill exhibited a spectral coherency and a dynamic transient as if a coalescence with the Apogee’s ribbons occurred.
Modest in dynamics in relative terms, the all-aluminum integrated amp nevertheless induced impressive strides of attributes to exemplify its complimentary companionship to the Tannoy’s.
The $16k pair of the 23 Wpc, Audion Golden Dream mono-blocks demonstrated vastly different personality, surpassing the Loth X in dynamics and sheer output, and nearly exhibiting Linn Klimax Twin’s ability in vanquishing the Tannoy’s to produce agile transients.
Featuring unique circuit topology and transformer design, the Golden Dragon 300B-equipped mono-blocks sounded surprisingly atypical of other 300B-based designs. When driving the Churchill’s, the Audion-induced top-end was relatively less refined with less prominent tonality when compared to the Loth X JI300. Yet, by SET standard, the Golden Dragon’s remained exquisite in its tonality via the Churchill’s in absolute terms, while the dynamics and transients produced by the Audion’s were powerful and tantalizing.
With the Churchill Wideband’s efficiency, many readers preferring 300B amplification will appreciate the Audion’s powerful, uncommon dynamic capability, distinct transient signature, and of course, the lustrous tonalities as only SETs can promise.
Consistent with top-class high-efficiency designs, such as the AN-E SEC Silver and the recently reviewed Royal Device Laura Studio Mk II with Miranda Horn system, the Tannoy Churchill Wideband loudspeakers offered vigorous dynamics as accorded by an accommodating efficiency towards amplification.
The centrally-fitted, Dual-Concentric™ point-source tweeter and large single-cone method had a consolidating effect on sound wave dispersion, generating articulately energized sonic wave front with the directivity and wholesome dynamics of the Klipschorn, and the spectral uniformity of the Apogee, thus summarily surpassing feats accomplished by both.
When propelled by a tonally vibrant and dynamically competent amplification as exemplified by the Audio Note M5 and Linn Klimax Twin, the scales of instrument and voice as projected by the Dual-Concentric™ method carried such degrees of spectral congruity and holistic tonality that set it far and apart from non-DC speakers. In addition, the DC dispersion pressurized the room profoundly with a level of sonic envelopment and emotional involvement seldom manifested by other speakers. Two 15-inch woofers working hand-in-hand in a 336 square feet of space proved to be impressively and sufficiently inundating, and they ought to be able to do the same for most listening rooms.
Lastly, when playing SACDs via the Sony SCD-777ES, the Churchill’s ultra-high frequency reproduction via its SuperTweeter™ induced livelier presentations consistently, and disconnection of the ultra-high frequency driver via the corresponding ‘VHF” terminals deprived RBCD’s and SACD’s alike of the sensation.
Continuing a rich, British legacy, the Tannoy Churchill Wideband produced some of the most involving sound ever. With an efficiency that invites amplifiers of all practical sorts, and with a supremely coherent spectral presentation for all practical listening enviornment, the Churchill’s represented a thoroughly balanced, consummate act yet to be surpassed.
The $20k Churchill Wideband has a smaller sibling, the $8,000, Dimension TD10, featuring an 10-inch Dual-Concentric™ and a SuperTweeter™ no less. We shall find out what the smaller Tannoy has to offer in an upcoming review.
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