Reviews

Kurre

AUSTRALIAN HIFI April 1998

They say you're supposed to tell the doctor everything so I'll confess. I finished reviewing Dr Rod Crawford's Kurre loudspeakers nearly six months ago, 'way back in 1997, but they sound so delicious, I really haven't been able to part with them, so I haven't yet sent them back. By the time this review appears in print, the speakers will no doubt be home with their designer in Canberra and your reviewer will be wondering if any other small bookshelf speaker will ever be able to measure up.

The Equipment

They say that beauty is only skin-deep, but that's not true in the case of Legend's Kurre loudspeakers, because what you'll find inside the cabinet is almost as beautiful as what's outside.

Take, for example, the nicely-crafted Audax bass/midrange driver (HM17OZO) located at the top of the cabinet. (Yes, the top. The Kurre uses an inverted geometry, where the tweeter is at the bottom of the cabinet, and the mid/woofer is at the top.) This is a lovely little driver, with a large magnet, a fully-cast frame, a rubber roll surround and Audax's unique 'aerogel' cone. This aerogel material, for which the company holds a number of patents, uses carbon-fibres to impart stiffness to the cone, to prevent break-up and ensure the cone acts like a piston over its entire operating range. However, to prevent the resonances that can occur in carbon-fibre reinforced designs, Audax also incorporates a gel-like material, to provide a measure of damping. Both are applied over a paper base. To ensure the casting doesn't ring audibly, Legend has filled most of the voids with a black, flexible, epoxy-like material. Since heat dissipation in the frame helps keep the magnet cool, the penalty for filling the voids in this way is presumably a very slight reduction in power-handling capacity, but this certainly wasn't apparent in the listening sessions, as you will discover.

The Audax driver is recessed into the front baffle so the frame sits flush with it, and is secured by four hex-headed bolt our preferred method of driver attachment. The driver is gasketed to prevent air leaks. The method used to secure the gasket, and the washers underneath the bolts, is such that I would not recommend users investigate the mounting method for themselves, because proper replacement requires a new gasket to be fitted - you cannot re-use the old one.

Despite the 170 mm claim for the bass driver diameter, this is actually the spacing between the mounting holes in the basket (a measurement method with which I personally disagree, but one that is common in the driver manufacturing industry). The actual diameter of the cone itself is 119 mm, increasing to 140 mm if you elect to include the rubber inverse-roll suspension (again, I don't believe in including the roll surround in the measurement). This puts the effective cone area at 111 cm2.

The tweeter is from Scanspeak, a lovely 28-mm fabric dome unit (D2905) with a fabric roll surround. The tweeter is recessed into the front baffle, and surrounded by stepped layers of felt, which modify the dispersion characteristics and also ensure there is no possibility of edge reflections. If these drivers sound familiar, it's because they are. They're the same drivers Legend Acoustics uses in the much-larger Kantu design, which I reviewed last year (Australian HI-FI Volume 28 Number 6.)

Inside the cabinet is a nicely-laid-out hardwired nine-element crossover that uses three cross-mounted air-cored coils, seven polypropylene capacitors and three ceramic resistors in a fairly unusual configuration (two additional resistors are added, one across the bass driver, the other across the tweeter). Internal wiring is all silver-plated van den Hul multi-strand cable that is soldered at every joint: at the driver end to the driver terminals and to the bi-wireable rear terminal block.

Internally, the cabinet shows signs of having been extensively worked. The first stage of working involves the positioning of wedgeshaped sections of rough-sawn softwood on the bottom sides and top of the cabinet. Cabinet bracing is provided in the form of a []-shaped brace in the centre of the cabinet, which locks the cabinet walls tightly together.

In the bottom half of the cabinet, behind the woofer the internal damping arrangement comprises a small amount of natural teased wool fibre that is sandwiched between two squares of 'dimpled' acoustic foam. In the top half of the cabinet, behind the tweeter, a large amount of teased wool is inserted, but this time without the acoustic foam.

Like all Legends designs, the Kurre cabinet is available in a range of Australian wood veneers, and the quality is magnificent. The baffle is finished with a high-gloss, textured painted surface. There isn't a grille, as such. Instead, the grille is stretched around the front baffle, and captured at the edge in a slot formed between the main part of the cabinet and the front baffle. This is a very clever design that cuts costs, eliminates the possibility of grille rattle and diffraction and means you can very easily make grille cloths in a range of decorator designs and colours, should you wish. I have to admit that I had my reservations about the deep blue-coloured cloth provided with my review sample. It wasn't a colour I would have chosen.

Aware that some audiophiles are not so much turned on by appearance as by sound quality, Legend makes a vinyl-clad version of the Kurre, which sells for $990. Given the high quality and realistic appearance of today's vinyl finishes, many audiophiles (and, no doubt, all 'greenies') will be happy to purchase this version of the Kurre and pocket the $200 they save by '50 doing. (Personally, I'd rather fork out the extra for the real-wood finish.)

On the rear panel are two sets of inputs, with the (+) and (-) terminals joined by extremely thick brass buss-bars. These, of course, should be removed if you're biwiring and left in place if you're not. You should make a special note, however, that the terminals are arranged oddly, in that the two (+) terminals are at the 'top' and the two (-) terminals at the bottom. This is the complete opposite of most four-terminal designs, which have the (+) and (-) terminals running vertically As a result, I would recommend extreme care when connecting your speaker cables to the Kurre. In wiring could possibly result m damage to either the speakers or to the amplifier.

Backgrounder

Since this is only the second review of a Legend product Australian Hi-FI has published, and many readers may have missed the first review, Legend Acoustics is a relatively new addition to the compendium of Australian loudspeaker manufacturers . Its owner and designer, however, is anything but new to the loudspeaker design fraternity, having served several years in the employ of Linn Products in Scotland, where he was responsible for designing the Nexus, Helix, Kaber and Keltic before returning to Australia to live. (Well who'd want to live in Scotland?)

Setting Up

The architecture of the Audax drivers (they have an exposed voice and a rubber phase plug) is such that I would recommend using the Kurres only when their grilles are in place, because the fine-weave fabric cloth will prevent dirt and dust particles from contaminating the (very small) gap between the voice-coil former and the magnet. It seems that Dr Crawford agrees with me, because the Owner's Manual provided with the speakers indicates that the frequency balance of the Kurres has been optimised for operation with the grilles in place.

The upside-down geometry means that it is absolutely essential that the Kurres be operated on stands, a bookshelf, or a wallmount bracket. Also, I'd recommend against mounting them on any type of soft surface, because of the possibility of high-frequency absorption of the tweeter's output. Finally, if you are mounting them on a bookshelf, make absolutely certain that the front edge of the Kurre cabinet is level with the front edge of the bookshelf.

Unlike many modern speakers, the Kurres are supplied as 'left' and 'right' speakers, so make certain you mount them as such. The Owner's Manual has a very clear diagram, but in essence, the array is such that when you're looking towards the speakers, the tweeters should be inner-most. Having already experienced the Legend Kantu speakers, which didn't like to be toed-in to face the listener, I was not at all surprised to find the Kurres are identical. Face them directly up the room. Where you position them with regard to walls depends on your domestic arrangements and, if we're to believe what we read in Owner's manual, on your tastes in music. The manual says "When sited with a wall close behind them, the lower notes will be reinforced to extend the bass performance for rock and contemporary music. When sited away from walls, the soundstage (positioning of instruments) will be optimised for jazz and classical music." I realise what Legend is getting at, but I am not sure I agree with the way it is expressed. This advice would seem to suggest that you should not listen to a rock band performing in the concert hall of the Sydney Opera House, or the Sydney Symphony Orchestra performing at the Entertainment Centre. The nub of the matter is that if you want a slightly bigger bass sound, but are prepared to accept some bloom at lower frequencies, by all means push the speakers back against the wall. If you'd prefer a more delineated bass, and are happy to sacrifice some bass output to get it, operate the speakers away from the walls. In reality, I think that if you're prepared to fiddle with speaker placement, listener position and room furnishings, you'll be able to get the best of both worlds.

After experimenting with three mounting systems (bookshelves, wall-mounts, and stands) I have to admit that in the end, my aural (but not visual) preference was for quite tall stands that raised the tweeters up to seated ear level. This meant the cabinets were actually quite high and visually prominent in the room. An alternative would be to use slightly lower stands and to tilt the speakers backwards slightly, so the tweeters fired 'up' to the ear. Wall-mounting however, also worked particularly well. In a room with a standard-height ceiling (mine isn't) I think you might get excellent results mounting the speaker near the wall/ceiling intersection, so long as the cabinets could be aimed downwards at the listening position but - and this is important - if you do hang the speakers from the ceiling you MUST turn them upside-down, so the tweeter is uppermost.

Listening Sessions

I think the bass alignment of the Kurre has been managed so well that even though different listeners might have slightly different preferences when it comes to positioning, it really does come down to personal preference - nothing more. The combination of a small sealed enclosure and a small bass driver does not bode well for bass response, so I was not exactly surprised that the Kurre's bass was neither overly extended, nor overly 'big' at low frequencies'. That said, I have to say that the bass is so well-balanced against the midrange, and has such a gradual and graduated roll-off with such low distortion, that it really does trick the ear into imagining there is a lot more bass present than there really is. This is a well-documented psychoacoustic trick that's been known about for years, but is always difficult to pull off, probably because designers make the mistake of forgetting to concentrate on overall balance, rather than just on extension. I think that in the Kurre, Crawford has managed to pull it off. The result is that when you're listening to bass lines, they almost seem to be an octave lower than they really are. You get the aural satisfaction of big bass without the big cabinet, the big drivers and the big price tag. Of course in the end, like the proverbial mirage, it is all an illusion, but it's so musically satisfying that it seems churlish to say so. How much bass are we talking about here? Well the Kurres are essentially linear to the ear down to around 70-Hz, which in musical terms is the two octaves below middle C, after which they still bass, but at a much diminished level. So, as you can see, you're not really missing too much, and certainly you're getting no less bass than you would from any other speaker with the same-sized bass driver and IB cabinet.

Tonally, the bass is very tight and immediate, without the subtle looseness' of a bass reflex design, but the penalty is that you also lose some of the bassy-ness' of the sound: it's as if a little of the raw edge is attenuated. This is not really apparent when listening to most instruments, but is noticeable with percussion.

The midrange sound is well-balanced and smooth with a pleasant warmth that is most noticeable when listening to female voices. Interestingly (since the speakers share a driver), I didn't think the sound was quite as rounded as the Kantu - though I would be the first to admit that this is a stretch of aural memory (albeit assisted by detailed notes)! You'd really need an A-B to sort this out. I was particularly taken with the way in which the Kurres handled Canadian chanteuse Holly Cole - I don't think I have ever heard Calling You sound more ethereal.

High frequencies were crisp and defined. I thought perhaps a shade of 'air' was missing from the sound as rendered, but the effect was very slight.

I was genuinely surprised by how dynamic the Kurre design is, and how loud and efficient they sound, even in a relatively large listening environment. Indeed in terms of dynamics, I think the Kurre is the most dynamic small speaker I have heard for some time. The relatively high efficiency is also a plus, since it means that unlike most small speakers, you won't need to invest in a powerful amplifier.

Conclusion

Legend's Kurre is a serious little two-way that seems to have been formed and voiced very much in a British mould. If you're currently auditioning small or even large twoways from any of the more famous British manufacturers, do not make a final decision without auditioning the Kurre.

Greg Borrowman

 
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