Centaurus Major & Minor review from Hi-Fi News July 1991

MAJOR TO MINOR

THE APOGEE CENTAURUS

Making its ribbon technology even more accessible, Apogee follows the Stage with two new models, Centaur Major and Minor ...

by Ken Kessler

Feeling a bit like the boy who cried ‘Wolf!’ I still can't help but regard this new range from Apogee as ‘ribbons for the masses’. But unlike the last models, which inspired this sort of reaction -, Stages and Calipers - the new Centaurs really do make Apogees accessible to a wide range of consumers. And not only by virtue of cost.

The name, credited to Brian Rivas of Pinewood Audio, is the neatest yet to denote 'hybrid' - I'm surprised it hasn't been used before. And as the Centaurs are hybrids, with traditional Apogee ribbons mated to dynamic woofers, the company has chosen to regard them as a truly separate model range. Some of the practical concerns and the behavioural characteristics of the Centaurs differ drastically from the full-range Apogees, so there's no real problem with the two series (fullrange and hybrid) overlapping in price; the dearest Centaur is quite unlike the least expensive full-range model. The Centaurs will invite into the fold a number of hi-fi enthusiasts who, were tempted by the full-range models but wouldn't give up their existing amplifiers or make room for speakers craving whole square metres of lebensraum. The Centaurs, unlike their all-ribbon siblings, rewrite the 'rules of Apogee ownership as follows:

(1) High sensitivity and a 6ohm impedance make them suitable for 'real world' amplifiers. I've heard them work beautifully with a 50W/channel NAD.

(2) The Centaurs give up little 'air' even when placed within 12 inches of the back wall. Hell, they sound pretty swell when shoved right up against the wall, because the depth of woofer enclosure keeps the ribbon at least eight inches away from it.

(3) They work with valve amplifiers, including tiny ones.

(4) They offer the decades-old familiarity of cone-sourced bass.

I could rattle off a list of little budget amplifiers which made the Centaurs, especially the Minor, sing beautifully, but I don't want to suggest that they can't justify the good stuff. Believe me, you'll know the difference between a Centaur powered by some monster amp and a Centaur running off a wee Rotel or Pioneer integrated. It's just that it's so nice to be able to talk about ribbons without having to qualify every remark with 200watts worth of class-A amplification.

The range consists of three models: this review deals with the Centaurus Minor (£1,149), at the bottom of the range, and the Centaurus Major (£4,200) at the top. (In between is the Centaur at £1,645.)

From the front, these speakers took like traditional Apogees which have been squared off, and have their bass ribbons covered by black grilles instead of the familiar see-through mesh. But now the grilles cover large baffles containing dynamic woofers rather than planar-shaped bass drivers.

At the back, you see the enclosures dedicated to the woofers, which conveniently provide each Centaur with cross sections that preclude the need for the 'legs' which support the 'all-panel' models. Apogee provides screw-in spikes, which allow you to dial in some tilt, as important here as it is with the Stages if you wish to recreate 3-D) with any accuracy.

In case you were hoping that these populist models did away with finicky installation, think again. They're revealing enough to keep you awake at night contemplating new speaker leads, while the toe-in and tilt requirements make up for the relatively uncritical spacing vis-à-vis the back wall. And easy though they are to drive, they'll show tip weaknesses, which amplifiers have in areas other than power delivery. One amp I tried which bordered on the magical at medium levels fell apart when asked to drive them with brio. Although it could produce the SPLs, the sound turned coarse and lumpy, And yet the very same amplifier Would allow the more ornery Celestion SL700s to bellow with finesse, so don't be misled by the comfy impedance.

The 26in dipole ribbon in the Centaurus Minor works from 800Hz up, with a 6.5in woofer crossing over at that point in 12dB/octave steps. In the Major the crossover point for the 40in dipole ribbon is 450Hz, with the bottom octaves handled by a 10in woofer. The ribbons are the familiar Kapton-backed Apogee types, using high-energy strontium ferrite ceramic magnets.

The Major can be bi-wired or bi-amplified, while the Minor cannot. Given that the Major revealed the worth of bi-wiring in a most emphatic manner, I can only dream of what this enhancement would do for the Minor. But I was informed by Apogee that dealers in the home market were emphatic about simplified connections for the Minor, while State-side pricing is so critical at this point that the extra few bucks for splitting the crossover and fitting more five-way binding posts would push it into the next bracket. Perhaps the company can be persuaded to offer a bi-wireable export version for the more sophisticated European market?

Both speakers offer coarse adjustments via toggle switches next to the speaker terminals, a feature common to other Apogee models. The Minor's toggle selects between 'normal', 'high' and 'low', for 1.5dB cut or boost of the woofer levels, this may sound like a trivial amount, but its usefulness in compensating for either live or slightly absorbent rooms cannot be undervalued.

The Major offers the same contour options, as well as a three-position switch for the mid/tweeter ribbon. The bass control boosts the woofer level by 2dB, for a warmer sound, or creates a 2dB cut for a tighter sound. As with the Minor, the dynamic properties change slightly, showing increases or decreases in the system's Q. The Major's treble control can be used to reduce the mid/treble output by 1dB or boost it by 1.5dB. With both speakers I listened with the controls at 'normal'.

Description

The Minor measures 100cm tall, 35cm wide and 225mm deep. We arc talking small, so even if you do use them away from the wall -18in is a sensible minimum - you're not looking at an overwhelming intrusion. Should you have to place them close to the back wall you may find yourself using the bass cut.

The enclosure for the woofer is a scaled cabinet measuring 710 x 200 x 180mm (hwd), and it's not seen when you view the speaker from the front. The grilles are permanently fixed so all I can tell you about the 65mm woofer is that it features a 25mm voice coil and its cone is made of mineral-filled polypropylene, with a synthetic rubber surround. The Minor is finished in a dark grey paint which is not unlike 'Hammerite'.

While Apogee doesn't state the sensitivity, the Minor is a 6ohm (nominal) load, with a 4ohm minimum. A 50W/channel amplifier is recommended as the minimum, with 100 W/channel maximum. And Apogee says that the Minor will deliver 107dB peaks at 4m using a 50W amplifier. In hands-on terms, I (trove this to what I consider uncomfortable levels 98dB at 1.5m with a 35W/channel valve amp without detecting a trace of clipping from the amp or any rasp from the speakers. And that's in a room with low ambient noise levels, so I'm talking loud. Frequency response, by the way, is stated as 40-20kHz.

The Major is another story entirely. In in addition to an extra 9 cycles down below, the Major seems more sensitive despite a minimum recommendation of 80W/ channel (200W max). But it's the change in the sonic character - greater weight at all levels - rather than easier 'driveability' which creates this impression.

The Major is not for the space shy. Standing 163cm tall, with a 46cm wide frontal aspect and total depth of 30cm, the speaker is only slightly less imposing than a Duetta or a Diva. The standard finish is the same anthracite colour as that of the Minor, but the review pair arrived with the optional rosewood veneer and looked positively gorgeous. Also available arc walnut, blonde oak and mahogany, so aesthetes who despise the invasion of, ‘yuppie grey’ you do have alternatives - or a more harmonious blending of speaker and room decor.

As with the Minor, the woofer enclosure is not visible from the front. it measures 107cm tall, but - instead of a square cross section as in the Minor - it's 28cm deep, with a frontal width of 27cm and a back panel width of 20cm. In both cases, the woofer enclosures are rock solid and internally braced, while the shape of the Major's cabinet is intended to further reduce the effect of internal standing waves.

The Major, too, works best with a minimum of 18in clearance from the back wall, but you can just about get away with flush placement. With both speakers, fine tuning involves the usual Apogee four step, juggling tilt (using the screw-in spikes), toe-in, fore-and-aft placement and left/right positioning. The manual is full of useful tips; follow it closely and you will be up and running in under an hour.

What's important for those who might consider the Minor because of its suitability in small rooms is the optional stand, which adds a few inches to tile height but - more importantly - adjusts the tilt for near-field listening.

Sound quality

My main concern with these speakers involved amplifier selection. Using familiar battery of sources - Lyra Clavis cartridge, SME V/ Oracle front end, and CAL and Marantz CD-12 CD players - I spent most of my time swapping amplifiers trying hard to find one which wouldn't drive the Centaurs. Let me tell you something else: nobody, And I mean nobody, has heard what an Apogee can (to unless they've used valves. And, as we all know, this has been denied us because of' the hideously low impedances of the full-range models.

A £499 Croft Series 5, a Radford STA-25 a 35W/channel from Woodside costing roughly the same as a pair of Minors and sonic 100W monoblocks from Ray Lumley, drove the Minor to adequate levels… and the Major.

I'm not touting the Centaurs as having sensitivity in the Lowther/Klipsch region A wonderful little ensemble tube/MOSFET, hybrid (£ 1200 or so) had to work hard with the Minors, but - within reason they sounded divine. The Croft struggled with (lie Majors, but handled the Minors with embarrassing case. As for the rest of the amplifiers: no sweat, And while I would expect 200W/channel's worth of' D'Agostino Delights to do marvellous things to the lower registers, the dynamics, the headroom and the attack, I refuse to lose sight of the cost element.

So how do the Centaurs differ from the full-range specimens? In a word: punch. Played side by side with Divas or Stages, the Centaurs show you the difference between planar woofers and acoustic suspension cone woofers. The former arc smooth, visceral, tangible. Despite the weight and extension, ribbon-derived bass is understated, almost incidental. Graft a cone onto a ribbon and you add greater slam, attack, and presence. The kick, especially from percussion and electric bass, will disarm any who have criticized full-range Apogees because they didn't like or comprehend the nature of ribbon bass, The benefits of' a sane impedance, greater sensitivity and easier room matching are mere bonuses. In tile Sound stakes, it's a happy marriage for those who quality for Category No. 4 [see intro]: listeners who can't make the leap from dynamic woofer sound to planar bass.

In a may, this undermines one consistent Apogee trait, that of refinement. It's like replacing the tyres on your Mercedes for low-profile road huggers, Sure, the grip improves, but you can definitely kiss the ride good-bye.

The real magic, though, is in the blending - which makes me sound like a coffee expert, I know, but it's the truth. My favourite hybrids - the Celestion 1000’s, the Martin-Logans and so on - work well because the designers knew how to segue two different technologies. Apogee took 10 years from its inception before it felt that a ribbon/cone hybrid met its standards. And the wait was worth it.

The trick, as Celestion found when crossing over at higher-than-expected frequencies, was to find a woofer as controlled, well-damped and fast as the ribbon element. Try though I may, I couldn't find anything, which betrayed this miscegenation. Tough acoustic tracks, lots of solo recordings, all-brass ensembles – the sound was 'of a piece'. Using my current fave track, the peerless Ruth Brown performance of ‘If I Can't Sell It, I'll Keep Sittin’ On It’, I tried to listen through the music for Minor or Major flaws (and to think I resisted the puns almost to the end. . .), but both models said, 'No way, jack, you're gonna listen to the music', Which I most certainly did.

Hey, these are like old friends, tight bottoms notwithstanding. The familiar Apogee sweetness (here's where the transistors lose out to the tubes), palpable three-dimensionality air, a sense of real space, image precision, midband warmth …Ruth Brown was in the room, gassy as all get out and swinging to beat the band.

Conclusion

The Major is serious stuff, a true, high-end Apogee but with the kind of bass you'd expect of an ATC monitor or other dynamic masterpiece. It will do justice to amps which come in crates. It paints a picture from wall-to-wall and floor-to-ceiling. But the Minor is even more satisfying because it costs less than a third of the price and will work in tiny rooms. What you give up is barely significant when you factor in budget and space. And that makes it even more of in achievement.

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