Impulse Ta'Us Loudspeaker

Francis Vale

The Sufi/Dervish sects believe that only those who know "how to hear music" will experience true spiritual ecstasy, and thereby know higher order truth. Some Dervish dancers have even been said to die while in the throws of their ecstatic experience,. Obviously, an audiophile's fervor is but a pale shadow when compared to the Real Thing. But although our quest is not anywhere near as meaningful as that of a Dervish or Sufi, it makes the pursuit of audio truth no less worthwhile. After all, truth, and its liberating effects, comes in many shapes and guises. To wit: Gordana and Francis recently had their own lesser order experience; one which shattered many of their pre-conceived notions. It came in the form of Ta'us horn speakers, the top of the British Impulse Loudspeaker line.

The horn speaker renaissance in the U.S. has been attracting a lot of attention in the audio press, so we will leave the technical and historical background to others. But here is a little hornucopia: an otherwise rational husband sent his family away for a couple of weeks, and when the wife and tots came home, they found a huge device snaking out from the back of the house and out over the length of the garden, and inside, where a living room wall had once been, the gaping maw of an enormous bass horn now loomed. Horns naturally bear their own seductive seeds for audio dementia.

Our trip down Amalthaea* Alley began as soon as the Ta'us' protective wrappings were shed. Gordana's first impulse upon seeing the speakers was to lovingly caress their facades, with their impressive English Cherry woodwork. (Naturally, Francis immediately stepped in front of them.) This elegant wooden facade, with a cross section in the shape of an elongated ellipse, was specially developed for Impulse by the Design Council of London. And behind this facade, cum rigid baffle, stands the black painted, MDF speaker enclosure itself.

While this wooden facade is no trompe l'oeil, the speaker's largish bulk (48" H x 12" W x 19" D) nonetheless managed to disappear quite nicely into our apartment surroundings. Moreover, you don't have to move out once it moves in, as the Ta'us relies on being close to a wall for horn reinforcement. Whereas many high end speakers make demands upon you to give up your living quarters like an evicting sheriff, this by-necessity, space saving design is a godsend for people living in apartments -- or who don't want to blast out the rear of their house.

The Ta'us is at the top of the Impulse product range and this three way speaker should sell for about $6,000 through regular U.S. distribution. The other two speakers in the Impulse lineup are the two way Kora and Lali. (They are all named after traditional musical instruments; a Ta'us being an Indian, bowed string device with a peacock-shaped soundbox.) This speaker trio represents the next generation of Impulse horns, and incorporates much hard won experience. The company traces its family roots back to 1974, starting out life as a desultory crew of British lads making some speakers for fellow enthusiasts.

Designing great horn speakers is as much about passion and courage as it is science (and also seems to require a touch of madness). The horn holy grail is a great speaker with minimal coloration. Horns will have your music echoing like some soaped-up bathroom baritone if they are improperly executed. In this case, the Ta'us horn speaker design is especially well thought out. Starting at the top end: Its tweeter goes from 4.5kHz to 20kHz, and is made by Focal. This 30mm (1.2") inverted dome features a special fiberglass diaphragm. Impulse says the fiberglass design gives it a very low resonant frequency, below 1KHz. Located above the tweeter is the midrange driver, a 109mm (4.3") doped paper cone similar to that found in many conventional box speakers. This driver sits at the speaker's rear, firing directly into a wood carved, parabolic horn, and carries the musical load from 750Hz to 4.5kHz. The Ta'us horn is also enclosed at the back and top. This blocked-off, rectangular horn reflects the company's experience with the speaker's predecessor, the H2, whose midrange horn was open to the rear. The redesign is meant to reduce cancellations (which can interfere with imaging) arising from listening room variations. The Impulse horns are carefully crafted, so the sound is not bounced back and forth off the horn walls on its way out. Tonal trampolining off the horn can cause time-smearing, producing a very nice echo, echo, echo....


Sitting underneath the tweeter is a 215mm (8.5") doped paper bass driver. It does all the deep breathing below 750Hz, and uses a low pass filter with a 12db/octave slope. The Ta'us bass gains extra woof on its way down to 40Hz via a modified exponential horn, which has its exit mouth at the base of the speaker. Now, a full fledged bass horn can be quite enormous -- see Home Improvement, above. In this case, size does matter. (Guys: Gordana, the psychiatrist, says not to worry.) The Ta'us needs something to overcome its internal space limitations. So the needy bass horn uses your floor, as well as a nearby wall, to augment it.

It's also a clever horn. The bass horn carries its own floor around with it: a heavy steel plate bolted below its mouth to avoid sonic variations from different floor surfaces (not to mention floor thumps by an agitated broomstick from the neighbor down below) A 2" gap between the plate and speaker mouth perimeter lets the low notes spill out. Rubbery pads are also affixed to the plate. Part of their job is to keep the metal 'floor' from ringing like the Bells of St. Mary's when struck by a falling Niagara of bass notes, But these are no ordinary rubber bath mats. They are Spectral Dynamics' Deflex panels, and are incised with numerous, deeply sculpted, concentric rings. The ringed design acts like a sonic focusing 'lens', providing improved acoustic clarity. Horn designers are nothing, if not obsessed with the details. (Note: Deflex Panels are also sold for use inside other speakers.)

Finally, four adjustable floor spikes are screwed into this rubberized metal plate. But these parquet-crucifying, medieval-inspired spikes quickly had to go, as they were rapidly making mince meat of our apartment security deposit. On a guess, we taped four, home friendly, Black Diamond Racing Cones onto the Impulse faux floor. In addition to being saved from Landlord Wrath, the speaker's sound, from top to bottom, clearly tightened up. (After hearing of this change, Impulse Loudspeaker told us it was already considering the use of a similar spike-replacement tweak on future models.)

All three drivers are masked behind a removable black cloth grille, and they occupy the top half of the 48" high enclosure. The three units yield a 94db sensitivity speaker when marshaled by a hard wired, passive crossover, This sensitivity figure, albeit not earth shaking by horn standards, is still above the rest of the usual box speaker crowd. Its high sensitivity also puts the speaker squarely in mid to low powered tube territory. The 8 ohm Ta'us has a listed power rating of 100 watts. You can easily tri-amp the speaker, as it has three pairs of binding posts. All of you single ended Dr. Gonzo's out there can, say, put a 2A3 on top, perhaps a 300B in the middle, and maybe either a twin 300B or an 845 on the bottom. And then change them all around again! This is a speaker that will let you tweak till you die. Nordost also kindly made up a custom 8 foot pair of SPM cables for the Ta'us and its three pairs of binding posts.

Finally finished with all our caressing, we hooked the Ta'us up to a Woodside 35 watt tube integrated amp. Speaker setup was a snap. We placed them 84" apart, toed them in slightly, discovered they sounded better with the grilles on, played a little until we found that 14" away from the rear wall was optimal, and then -- Oops! That head over heels sound you just heard was Gordana and Francis falling into horn loaded love. It was easy to hear that something special was going on, even fresh out of their shipping crates.

What strikes you first about horns is their sense of immediacy. The music is just there: no hesitation, no shyness about tumbling out of the box. The Ta'us is absolutely fearless; a true sonic pugilist ready to take on all musical comers. And does the Ta'us have get up and go! 0 to over 100db and into your local Housing Court in nothing flat. A well executed horn like this naturally comes by an ability to put on an unrestrained performance.

For example, the IVth movement finale, 'pini della Via Appia', of Respighi's 'Pini di Roma' [BMG/DG D135381] has a driving, climbing, emotional intensity that the Ta'us delivered in full orchestral scale. In this section of the composition, conflicts of some primal sort are being worked out. (What is modern Italy, after all, if not a loose assemblage of nationalistic states flying in close formation?) If the sonic reproduction is lousy, then the tension of musical nation-creation will be conspicuously absent. The strings' brooding pessimism, not to mention the recalcitrant, moody piano, could easily overwhelm the emerging exuberance of the horns. But the Ta'us says the hell with you Prozac-crippled all. Est! Est ! Vita! Vinci! The speaker gives way to the incessant horns and to the ascending drums; sustaining their collective plea until even the piano comes round to their way of Garibaldli thinking. If it was any less of a speaker, it would have thrown in the towel long ago. But with the Ta'us, a nation is born before your very ears. Indeed, in his throwback mode, Francis could easily imagine himself a centurion matching back to Rome from Caesar's tripartite Gaul (sometimes his Italian genes get the better of him).

The Impulse horns possessed a remarkable ability to reproduce instrumental and musical details. But this was not just some self-infatuated peacock display. The music was always of a whole, Ta'us-created, cloth. Quite often, its startling ability to reveal the musical inner workings would cast a familiar recording in a brand new light; a great example being our original Columbia (mono) LP of Countdown, Time in Outer Space, featuring the Dave Brubeck Quartet. The now 34 year old foursome's performance suddenly acquired a new found synergy. For Brubeck, this 1962 album was all about rhythm, and how the constraints of time could be shattered by jazz. The then new space age became Brubeck's metaphor for moving beyond jazz 's traditional limitations of 2 and 4 time, and into a new rhythmic space/time. (An historical footnote: This album is dedicated to the astronaut Lt. Col. - now senator - John Glenn, Jr.) In this recording, cross-rhythms of different stripes were possible, and encouraged. These complex and sometimes delicate rhythms were often fought over, as the players would, for example, stubbornly refuse to get out of a 3/4 and have to be "nudged" back into a 4/4. If the speaker is dumb to these sometimes elusive timing changes, then all is lost; including Joe Morillo's subtle work on tympani. But the Ta'us obviously dug relativity, and let all this space time continuum jazz unfold before us. In a very real sense, the album cover notes were able to keep their yellowed promise: "You can purchase this record with no fear of its becoming obsolete in the future."

And what about the horn loaded bass? The double bass in jazz recordings was often rendered with so much tasty meat to it, you could serve it up for the Sunday roast. Moreover, the little Woodbridge tube amp, with its incredibly high damping factor (40), could have the Ta'us shaking the apartment walls. No, it doesn't dive way deep, but the Ta'us bass, as the designers' intended, was articulate and seamless. A good example is Talking Timbuktu [BMG/Hannibal D103178] with Ali Farka Toure, and Ry Cooder on guitars. These two musicians from opposite ends of the planet were obviously separated at reincarnated birth. The synergy is amazing. On this CD, there is a lot of bass drum 'air' moving around. We know from experience that, on a poorly integrated speaker system, this recording can produce a diffuse, out of focus, 'whump, whump, whump.' But the Ta'us effortlessly projected a clear cut drum happily hammering away to the infectious Afro-Mali/jazz beat.

In the beginning, the speakers had a rather shut-in soundstage. But it began extending way back and out to the sides as they racked up the hours. Moreover, the music never meandered about, and always was focused in the same plane. An unusually good test of its imaging capabilities was found in an equally unusual piece of music: the Balinese Ramayana Monkey Chant, [Voices of the Spirit," Ellipsis Arts, 5229-60187-2]. This music, adapted from a Hindu epic, features upwards of one hundred entranced, chanting men, sitting in a huge concentric circle. They sing the story of how the King of the Monkeys rescued the wife of Prince Rama from the evil King Rawana. During its rendition, the vocal leads are constantly passed around, making for a great imaging challenge. But they were all clearly delineated, with one singer, in particular, 'visibly' moving his way around the undulating, arm waving pack. The Ta'us also lets the highly charged singers give vent to some extremely complex contrapuntal emotions. Once again, the elusive qualities of rhythm, time, and emotional honesty are clearly displayed as being the Ta'us' stock in trade. Our neighbors also gave us a number of quizzical looks after playing this cut perhaps one too many loud times. Maybe it was our request for banana offerings....

Indeed, vocals are especially -- honestly -- convincing on these speakers. Here is a telling anecdote: Francis 's brother, whose audiophile tendencies stray to mostly, "Hey, turn that thing down!" was visiting us during a family get-together, when he wandered off and disappeared. At the time "Ella and Louis Again," [Mobile Fidelity, Anadisc 200] was playing on the remarkable Wilson Benesch turntable. Francis , curious, went looking for him. He found his brother standing, transfixed, in front of the Impulse speakers. He turned to Francis and said, "It's like they are singing right there in front of me." His statement is equivalent to a blind man suddenly saying he can see rainbows in all their glory. His wife was no less amazed: "Ernie said what?" It is magical events like these which make all that cliched sibling stuff worthwhile.

Now we come to the Big Question: 'But what about all that nasty horn coloration?' Not! And the one incident that caused us some colored concern turned out to be a red herring. It occurred when we hooked up our Rotel Michi RH10 tuner to the Ta'us system. FM music, and especially station announcers, suddenly sounded like they were broadcasting from the Bat Cave. To find out who or what was the hollow sounding culprit, we played some well recorded spoken text (e.g., Stereophile Test CD, track 5, J.G. Holt reading, Why Hi-Fi experts disagree). To our relief, the Ta'us horns passed this test of speaker accuracy with flying colors. So, in the end, we learned that the Ta'us was ruthlessly exposing FM's over-compressed deficiencies. If this was anything other than a horn speaker, we probably would not have been so quick to consider that maybe the Ta'us was at fault. However, all those hoary horn homilies had made us somewhat paranoid. But this is what happens when a widely held prejudice becomes engrained as ersatz Audio Truth: we go running off to find ugly things that may not be there at all. The Ta'us, despite its two horns, proved to have very low coloration, and be tonally balanced. It was also unsparingly revealing. The speaker's remarkable transparency strongly suggests using it with the best components, and source material.

Some words are required here about the Nordost SPM speaker cables that were made especially for this review. The speaker wire ends terminated in a triwire split for the three sets of Ta'us binding posts, but cleverly, the amp end only required standard wiring bindings. SPMs are not cheap; a custom triwire job like this 8 foot pair will set you back about $3,800. But oh lord, do the SPMs sing! The Ta'us is truly in the ruthlessly revealing category and the faults and limitations of lesser speaker wires would be quickly exposed. But the Nordost SPMs never had to worry about being undressed in public by the Ta'us. Top octave to bottom, the SPMs and the Ta'us played joyful music together. The SPMs are not just wires, they are a true high-end audio component all by themselves.

To close our review, let's come full circle and mention a piece of Sufi music, Haq Ali Ali Haq, which was especially stirring on the Ta'us. This mystical and inspirational work was sung by the great Pakistani Qawwali master, Nusrat Fateh Ali Khan [Ellipsis CD, "Harmony and Interplay," 5229-60188-2]. This piece will get your limbic system in full arousal. If it doesn't, you must be a Unitarian Universalist on a Wonder Bread diet. Originally, Ali Khan had no intention of becoming a Qawwali singer, but he had a recurring dream which convinced him "This was the path to follow." His words accurately sum up our new attitude towards horn speakers. Magical, irrepressible, and addictive, the Ta'us helped Gordana and Francis get to know "how to hear music."

*Amalthaea; the goat belonging to the nymph of the same name, or Archelous; who lost his horn when he took the form of a bull to fight Hercules. According to myth, this shorn appendage was transformed into the horn of Cornucopia, containing food, drink, and pleasure in endless supply.

Copyright 2000 Francis Vale, All Rights Reserved



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