It’s a bass reflex design based on pairing KEF’s latest and most sophisticated Uni-Q array with powerful new generation bass drivers in an elegantly curved cabinet that’s designed to maximise cabinet stiffness and minimise internal reflections.
Having listened to several speakers back in 2003. I eventually went with the KEF Q range. In 2010 I decided to upgrade to the IQ range. Major differences - The cones look really nice and the changed the speakers posts to this clear resin around the metal. The tweeter is also radically different. The base on the bottom does add some stability. I had the Q7 before and the weight is pretty much the same yet the Q7 did not seem as wobbly as the IQ90. It is very slight - compared to the IQ70 I got for the rears - which is rather bad. The build quality is not bad but just feel they a little top heavy. As for sound they sound typical KEF. I auditioned speakers from B&W as well as Paradigm. I also compared them to the KEF XQ range. I found the Paradigm Studios a little bright but awesome midrange. The IQ90 vs XQ40 was interesting...the XQ40 where better but I did not find them 3x better which was the cost difference. At best after 5 hours of comparative listening I would say maybe 30% better. Having lived with them for a while now I really do like them. The midrange and upper frequency is better than the Q7 but not the lower frequency. For the price however I found them to be excellent. If I could afford more I would have gone with the Paradigm Studio over the XQ but my KEF IQ90, IQ60c and IQ70 really do come to the party and deliver great in music and movies. You however will need a sub to get really good base. Get a 12 to 15 inch that plays down around 20Hz. I got the Paradigm SUB15 in my setup. Even the girlfriend agrees that there is far greater clarity in these IQ compared to the older Q. The Uni-Q setup that KEF uses does make a small difference in the sweet spot, especially at lower volumes compared to some of the other brands. I have bi-wired my front three and run them off a Yamaha. I have heard them off a Marantz, Onyko and Rotel. Sounds really good off the Rotel in stereo setup. They have just launched a new Q series which looks rather odd in the return-of-the-box format.
