KEF XQ30 £1499
8th Aug 2008 | 11:36
The new XQ range from KEF brings sophisticated technology to Uni-Q
The KEF XQ30 is an appealing slender floorstander from KEF's new XQ range, which currently includes a larger floorstanding loudspeaker, two compact two-ways and a centre channel speaker.
Currently there's no subwoofer in the range, although a dedicated model with matching finish will probably emerge in due course, although KEF does have subs in other ranges.
The XQ30 is the smaller of the two floorstanding models, an impressively slender compact that stands well under a metre tall and which, in the case of the test pair, is finished in a very fetching black gloss with a fine lacquer finish.
It's a three-way speaker, with a smallish dedicated bass driver supplementing a Uni-Q driver which, as always, incorporates a tweeter at the acoustic focus of the bass/midrange unit.
The system is front-vented and is equipped with discreet outrigger feet at the back, where the enclosure is at its narrowest, for stability.
KEF supplied the speaker with two different sets of floor-mounting hardware, a set of small pads which are intended for use on polished floors and carpet-piercing spikes.
Also in the box are foam inserts to help tune the reflex port. If you find the system overblown in the deep bass, then use the foam plugs to tune the bass down to around the port resonant frequency, which is somewhere in the 55Hz region.
Although KEF's patents on Uni-Q have lapsed in many territories, the technology has not been widely emulated elsewhere, though Tannoy use an alternative technology which does a similar job with Dual Concentric.
Over the years, KEF has progressively refined Uni-Q to keep it abreast of the market and the XQ range uses completely revamped Uni-Q drivers. Two areas in particular have been addressed.
First is the new profile for the interface between the tweeter and the bass unit, where the cone not only acts as a kind of horn loader for the tweeter, but is constantly moving fore and aft, therefore making this a tricky system to optimise.
The new design is said to offer a much smoother tweeter response and improved coupling between the two drivers. The other key change is the addition of the so-called Tangerine waveguide (the Tannoy counterpart, by the way, is known as the Tulip waveguide).
This is a shaped piece, which from the front resembles a segmented tangerine in cross section and is placed in front of the tweeter in close proximity to the dome. It's designed to apply acoustic loading to the tweeter diaphragm, which increases towards the edge of the dome, where the dome geometry least resembles an ideal section of a pulsating sphere.
Along with other changes, the units are said to offer better dispersion, improved integration and considerably reduced levels of harmonic distortion.
Construction of the system as a whole is undeniably impressive.
The XQ30 is compact and elegant, with a teardrop cross-section using curved vertical panels to suppress internal reflections and cabinet resonances. The enclosure is equipped with high-quality bi-wire terminals.
Both larger cones are 130mm in diameter and the tweeter domes are made from aluminium, with an elliptical profile 19mm in diameter, rather than being hemispherical.
Crossover frequencies are 450Hz and 2.5kHz , though the order of the crossover is not specified, sensitivity is rated at 87dB and impedance is rated at 8 ohms (nominal), though it dips down to 3.2 ohms. Power handling is up to 150 watts nominally and the system is magnetically shielded.
There are clear parallels between this model and the XQ20, as the XQ30 perpetuates the lean, dry balance of its smaller counterpart.
Its main components are a degree of tonal brightness and a suggestion – usually no more than this – of aggression associated with the mid treble. So the dry, bright tonal balance referred to in our review of the smaller XQ20, is mirrored here, but on the whole this does little to mar the listening experience in practice.
In the near field, the XQ30 is clearly very clean and explicit, while in the far field the system presents music with an almost tactile immediacy.
The XQ30 can be a bit fussy about the quality of recordings as it occasionally has the effect of emphasising their less desirable qualities.This is especially true of recordings that could be criticised as sounding overtly 'digital' in character, though unusually this also extends to some SACDs as well as Red Book CDs.
Our review of the XQ20 also identified some dryness in the bass registers and you might expect this larger model to be more extended in the LF, but the numbers don't support this: the -3dB point is 53Hz, 1Hz poorer than the XQ20 and, in practice, the balance of the bass against the overall sound is unlikely to be much different.
At the other end of the audio passband, the tweeter is said to extend to 55kHz (-3dB), so there is no need for undesirable expedients like external super-tweeters, which some KEFs have resorted to in the past.
In real life, bass extension is moderately good and clearly capable of dealing manfully with the sound of a full orchestra, but the numbers don't tell the whole story.
The treble still tends to dominate proceedings, by adding a sheen to the sound and emphasising transients with, at times, a suggestion of edginess or granularity. But bass quality is very clean, open and intrinsically well-balanced even if it isn't miraculously deep (the speakers having been positioned proud of nearby walls by 50cm or so).
Despite the wide dispersion of the Uni-Q driver, acoustic interaction with the listening room sidewalls was usefully low.
One fascinating feature of this model, however, is its exceptional stereo sound staging.
For reasons that are not entirely obvious and to a greater extent than with previous Uni-Qs, the XQ30 delivers an unusually holographic image in space, especially in the near field.
There's an unusual sophistication about the way individual instruments in a complex soundfield are reproduced.
They are portrayed in a manner that gives complete distinction from each another, which gives a far better, more realistic idea of a living, breathing soundfield and not just a bloated wodge of sound.
Other points that may well factor into any buying decision include the XQ30's dispersion, which places less constraints on the listening position. Though as this writer has found with Uni-Q, the brilliance of the sound takes a sharp dip when listening from well off the normal listening axis.
As an electrical load, the XQ30 appears to be unproblematic, despite the 3.2 ohm minimum impedance, though you will need to take care to choose ancillary equipment that is sympathetically balanced to avoid any sense of harshness.
The XQ30 sees yet another ramping up of Uni-Q technology, though the balance in some systems and rooms will be somewhat abnormal and this will have to be watched when planning a system, perhaps by choosing an amplifier and/or source component that's on the polite side of neutral.
Perhaps this speaker was primarily aimed at the Far Eastern markets, where popular musical tastes are often oriented to percussive sounds.
The clean, elegant lines and excellent finish of the XQ30 means it will slot in well in any domestic setting. It's also superbly detailed with exceptional imaging, which for many audiophiles is a very attractive quality.