pl | en
Standmount loudspeaker
KEF iQ30

Price: 1900 zł (set)

Polish distribution: GP Acoustics GmbH

GP Acoustics GmbH

tel. +49 2319860322
fax +49 2319860327


WWW: KEF Audio

Text: Wojciech Pacuła
Translation: Krzysztof Kalinkowski

We do write about KEF Audio from time to time, but since the last test, of the model C7, time has passed, and I cannot explain that. Although some conspiracy theory lovers would have us test a KEF product each month, because then they would have a confirmation of the paranoid accusation, that advertisements “translate” into tests (in our case the advertisement banners). Unfortunately there is nothing I can do about that, although I always try to meet the expectations of the readers of “High Fidelity”. But from time to time I pick some interesting position from the broad catalog of products, that the British company offers. That was the case with C7 (which earned the Product of the year 2009 award), and it hapened again with the iQ30. Those are medium sized, bookshelf loudspeakers, belonging to the basic series iQ. This is one of the series, that is manufactured for the longest time, and where technological changes were implemented also most often. Yet again, we have the letter Q in the name, which indicates, that it was built around the coaxial Uni-Q system (a system, that makes both loudspeakers have their acoustical centers in the same point). It was first introduced in the C series in 1988, and became a trademark of the company. The creation of such a loudspeaker system was made possible, because neodymium-iron-boron magnets became available – extremely powerful, yet compact. And those were needed, because the tweeter is located at a spot, where usually only the dust cap of the mid-woofer is placed. This placement method allowed creating a system, which propagates sound waves from exactly the same spot, and this is something worth fighting for. But at the same time we should acknowledge, that KEF was not the first one to this solution – the oldest coaxial system were presented even before WWII by Western Electric, and other companies, like JBL, Tannoy, Pioneer, Thiel, Altec and Cabasse (and also SEAS) had, and still have, similar solutions. However today – besides the Dual Concentric from Tannoy – this is the most widely known construction. I mentioned Tannoy on purpose – their idea for an coaxial driver is 63 years old – it was introduced in 1947! Uni-Q is about 40 years younger – so it should not be surprising, that it keeps changing. But it is still made from a mid-woofer and tweeter placed coaxially within it. This is at the same time the main difference with the Tannoy idea, where the tweeter is place behind the magnet of the mid-woofer, and the sound is radiated via a tube called Tulip Guide.

Although the KEF company materials name it the “new” Q series, and it has a suitable logo, in the official terminology it is named iQ. And yet, it is not the same iQ series as in the beginning – as since 2-3 years, the tweeter bears a worked out phase corrector called Tngerine, which is meant to improve the phase relationships in the transition point between the two drivers. And this is something you can see straight on. A second thing is related to the pair of loudspeakers we received for testing, with its finish: since 3-4 months a white version of the loudspeaker is available, bearing the same price tag as the basic version. And for the test we received this white version.

To date we tested the following KEF loudspeakers:


I used the following discs::

  • Feel the Difference of the Blu-spec CD. Jazz Selection, Sony Music Japan, SICP-20050-1, Blu-spec CD + CD; review HERE.
  • HiQualityCD. Jazz Selection, EMI Music Japan, TOCJ-90010, HQCD + CD; review HERE.
  • Ben Heit Quartet, Magnetism, Acousence Records, ACO80108, 24/192, FLAC.
  • Diorama, Child of Entertainment, Accession Records, A 119, SP CD; review HERE.
  • Electric Light Orchestra, Time, Epic/Sony Music Direct (Japan), MHCP-1161, CD.
  • Frank Sinatra, That’s Life, Reprise/Universal Music Company/Sinatra Society of Japan, UICY-94423, SHM-CD.
  • Kate Bush, The Whole Story, EMI/Toshiba-EMI, TOCP-67822, CD.
  • Madeleine Peyroux, Bare Bones, Rounder/Universal Music LLC, UCCU-1188, CD.
  • Milt Jackson Quartet, Milt Jackson Quartet, Prestige/JVC, VICJ-41534, K2 CD.
  • Monteverdi, Ottavo Libro dei Madrigali, Concerto Italiano, Opus 111, OPS 30-187, CD.
  • Robert Plant & Alison Krauss, Raising Sand, Rounder, 478020, 24/96, FLAC.
  • Sonny Clark, Cool Struttin’, Blue Note/Audio Wave, AWMXR-0003, XRCD24; review HERE.
  • The Eagles, Hotel California, Asylium Records/Warner Music Japan, WPCR-11936, CD.
  • Tool, 10,000 Days, Sony BMG Music Entertainment, 819912, CCD.

Japanese versions of the discs available on CD Japan

I learned that the loudspeakers have quite a high efficiency switching over from my Dobermann – the sound from the iQ30 was louder. And immediately another thing got confirmed – the loudspeakers from KEF need long burn-in time. I received it for testing completely new, although I always request “ready to go” gear, and I needed about a week, to get them enough burned in, that they could show what they have up their sleeve. But first a small digression. Based on my experience I can tell, that – roughly – we can split good audio gear, and good loudspeakers in particular, in two groups: one, which catches our attention from the first moment, from the first note played, which place us in their world immediately, and a second group, to which we have to mature, to approach them slowly, step by step. And I mean only good loudspeakers, I do not deal with bad ones. In both cases a music lover will discover their potential, but in both cases we need to reach a certain consensus, a certain balance, and that takes some time. The work we need to do is different in both cases – in the first one we need to scrap the sound from the “nice” and “appealing” elements, that catch us so much in the beginning, and in the second one, we need to reach those, that are important and valid. This means two opposite ways – to the “outside” and to the “inside”. I am sure, that you had many times a situation, where brilliant, at first glance, constructions started to annoy you with something in time, or even got you angry with something, while others became more noble, as if they would release their potential with delay. KEF iQ30 are good loudspeakers, very good even. But they are not in any of those categories.

If I would be attaching labels, then I would call them “paradox” loudspeakers. But please, take this with a grain of salt, because I mean something else, and not just a word play. Because the iQ30 catch our attention immediately, at first glance, and similar to interesting tube amplifiers, they enchant us with a dense and warm midrange, while on the other hand, I had to investigate for some time, why their tonal balance was set the way it is, and why the lack of lower bass does not hurt. I think, that this is a choice and a vision of the reproduced sound, a very personal one, as if one person would be standing behind the iQ30 project, what is not so common in big companies. The sound of those loudspeakers is built around a warm and dense midrange. But in my opinion, the brilliant treble are the biggest achievement. From time to time I encounter opinions, that KEF sound “muddy”, or that they are “dry” – people write emails, and I learn at least as much from the readers, as they from me. But sometimes I need to verify things, as I get contradictory signals.

So driven by curiosity, I listened to some discs to look at those aspects, and I must say, that in both mentioned cases, there had to be a flaw in the system elsewhere, which underlined those, and not the other characteristics of the sound. Well, the iQ30 are not super precise loudspeakers, in the sense, that they define the attack of the sound ideally, that they are splendidly resolving, etc. On the other hand, they can sound with quite strong upper midrange. Everything will depend on the rest of the system, they are connected to. But when we take a balanced, rather strong amplifier, then the assets of this sound will become obvious.

Like I say, midrange is most important here, as it sounds quite strong, but in reality the treble is the best. So I’ll start with those. A metal dome could not sound with such a natural sound, so vivid, even a few years ago. Even an expensive metal tweeter couldn’t. iQ30 does not cost much, but the fullness of the cymbals on the disc That’s Life Frank Sinatra, fantastically shown upper harmonics from the vibraphone of Milt Jackson from the disc Milt Jackson Quartet proved, that KEF has a good hand for this range, that the Uni-Q system with the Tangerine phase corrector does it job well. This means rich, saturated treble. And although the dome allows to transfer frequencies up to 40kHz, such a high border frequency does not translate into brightening of the upper treble – because that was never the goal! A wide frequency response allows for focused, phase coherent sound in the usable range (audible range). This is how it works. And here it works perfectly. How well sounded the hi-res recordings I played from the Naim HDX! Alison Krauss with Robert Plant from the disc Raising Sand (24/96), and the beautiful disc Ben Heit Quartet Magnetism (24/192) showed, that the widened frequency response is something normal, that the limits imposed on the CD, by using brick filters, are one of the reasons, that the CD sound is “plastic”. This is also true for loudspeakers – due to the splendid treble the KEFs showed the CD recordings nicely.

And still midrange is the strongest sub-range. After unpacking the loudspeakers from the box, they sound a little nasal, have an underlined lower midrange, and the part responsible for “air” is withdrawn. To some extent those effects disappear with mechanical changes induced by playing (so called burn-in), but never fully, and those define the sound of the KEF. To some extent this limits the amount of music, that will be reproduced in the way, the listeners would imagine it. And I am not talking about imagination by coincidence. Playing Tools from the disc 10,000 Days, or Diorama form the maxi single Child of Entertainment I received a balanced emission, without a trace of aggression, without sharpened treble. There was not a trace of blatancy in the sound, hat is rare, and what I taken with special satisfaction. There was not much of low bass, medium and upper bass played a bigger role. And yet rockers, and electronic music lovers demand dynamics from the loudspeakers, and some kind of “nerve”. This cannot be achieve with the given money, at least when the sound should be quite even, and not shifted to one of the ranges. This is why you need to adjust to such way of sounding. It is worth the effort, really, but I understand, that this will have to include a change in how we imagine, that rock should sound at home. But there is another side to the rock – older discs, where something else was presented – I think about discs like Hotel California The Eagles, Time ELO or The Whole Story Kate Bush – those sounded incredibly good. They were not so dynamic, but that what remained, was really well tailored to the size of the loudspeakers. The sound seemed bigger than the size would suggest, but in this case everything was in its place, and needed no correction of one’s expectations.

This is why I was talking about a certain paradox – those are warm loudspeakers, with splendid treble, which can sometimes seem too warm, and sometimes too dry. I also mentioned, that they are not excessively resolving, but this does not mean, that they do not show anything. In contrary – comparing the Blu-spec CD and HiQuality CD with their classic counterparts clearly showed the superiority of the new versions. Even when the changes were not spectacular, I always preferred the Bs and HQ versions. The sound stage is broad and wide, where the work of the Uni-Q shines. The definition of the sounds on the stage is nothing special, there is no clear differentiation of their distances. Bigger groups of instruments, whole planes, are preferred. And not the individual instruments. And that’s it. Those are not run-of-the-mill loudspeakers, with an not so common set of characteristics, that are hardly found together in one product. The loudspeakers should be placed far away from the wall, and they need a fairly powerful amplifier with well controlled bass, but not too bright, and then it will be really good.


iQ30 from KEF Audio is a medium sized bookshelf loudspeaker, in a bass-reflex cabinet. The basic technology used, is the proprietary Uni-Q driver system, with a 165mm mid-woofer and a 19mm tweeter. The first one is made from two layers – paper, reinforced with titanium from the visible side. The diaphragm is hanging on a rubber suspension. In the center, there is an aluminum dome tweeter, with an aluminum, characteristically shaped phase corrector in front of it. Just below the Uni-Q there is a bass-reflex port outlet, which, when needed, can be closed with a sponge plug, delivered as accessory. This helps in achieving desired bass control. The bass-reflex port is very long, and almost touches the back side of the cabinet. The input and output ends are rounded, and the whole is integrated with the plastic grille of the Uni-Q system, which covers the spider and mounting points. The Uni-Q is a solid driver, having a solid cast spider, and a big magnet. The cross-over frequency is set quite high, at 2.5kHz. The efficiency is also reasonable: 89dB. The manufacturer indicates also high impedance - 8Ω. However in practice, those loudspeakers are not so easy to drive, as one could expect from those figures, because impedance falls quite low – in the previous version it was about 3.2Ω, here it was improved a little, but not by much. You just need to have a very solid amplifier.

The cabinet is made from bent MDF elements, formed in the shape of a lute. Although historically Sonus Faber was the first to use this shape, which minimizes standing waves inside the enclosure, now many companies use it. The front baffle is also slightly rounded. Inside, just below the Uni-Q we have a grommet reinforcing the cabinet, and the inside is well damped with artificial wool. The cross-over is mounted on a small PCB and bolted to the back plate. There is an air coil for the tweeter and a core one for the mid-woofer. All capacitors are electrolytic. The connecting cables are mounted to the drivers using connectors. On the back, there is a plastic panel with cable terminals, with a shape fitting the cabinet. The terminals are double, not gold plated, but connected with nice cramps, made from silver plated copper cable. The loudspeakers are equipped with grilles. The tested loudspeakers were white. But this is not varnished wood, but just an artificial veneer in this color. However, it looks nice.

Technical data (according to manufacturer):
Cross-over frequency: 2.5kHz
Efficiency (2.83V/1m): 89dB
Maximum sound pressure: 110dB
Nominal impedance: 8Ω
Recommended amplifier power: 15-120W
Magnetic shielding: yes
Frequency response: 45Hz-40kHz
Weight: 6.45kg
Dimensions (HxWxD): 365 x 220 x 327mm
Available finishes: Black Ash, Dark Apple, American Walnut, White

g     a     l     l     e     r     y


  • CD player: Ancient Audio Lektor Prime (tested HERE)
  • Phono preamp: RCM Audio Sensor Prelude IC (tested HERE)
  • Preamp: Leben RS-28CX (tested HERE; soon to be changed to Polaris II, tested HERE)
  • Power amp: Luxman M-800A (tested HERE)
  • Integrated amp: Leben CS300 (reviewed HERE)
  • Loudspeakers: Harpia Acoustics Dobermann (tested HERE)
  • headphones: AKG K701, Ultrasone PROLine 2500, Beyerdynamic DT-990 Pro, 600 Ω version (reviewed HERE, HERE, and HERE)
  • interconnects: CD-preamp: Wireworld Gold Eclipse 52 (tested HERE; soon to be changed to Acrolink Mexcel 7N-DA6300, article HERE), preamp-power amp: Velum NF-G SE (tested HERE)
  • speaker cable: Velum LS-G (tested HERE)
  • power cables: Acrolink Mexcel 7N-PC9100 (CD; reviewed HERE) and 2 x Acrolink Mexcel 7N-PC7100 (preamp, power amp (reviewed HERE)
  • power conditioning: Gigawatt PF-2 Filtering Power Strip (reviewed HERE)
  • audio stand Base
  • resonance control: Finite Elemente Ceraball under the CD (article HERE ) Turntables change continuously, as do cartridges. My dream setup: SME 30 with Series V tone-arm and Air Tight PC-1 cartridge (also in the PC-1 Mono version).