The Uni-Q driver configuration is a signature KEF technology. The Uni-Q design precisely aligns the sound waves from the midrange and tweeter to create a unified sound field. The acoustic centers, or voice coils of the drivers are time aligned in order to achieve a 'point source' speaker where all sounds emanate from the same point in space. Interference between the sound waves from different drivers is minimized and the results provide a coherent sound quality with wide dispersion characteristics. A coherent speaker presents a sound wave as if listening to a single driver for all frequencies, not separate drivers interconnected by a crossover. In my experience, sound coherency is one of the most important and often overlooked characteristics of accurate music reproduction.
The Uni-Q array in the Q Series speakers has been further refined with a 'tangerine' waveguide surrounding the tweeter that helps direct and control the sound coming from the tweeter.
First Impressions: Movies
Good bass can be difficult to achieve even when speakers are correctly placed in a room with good acoustic qualities, but the iQ50s had great bass right out of the box with excellent extension. There were no apparent peaks or dips in low frequency response and bass sounded evenly distributed throughout the room.
A case in point was the sixth season of the Fox series '24' (DVD, Dolby Digital), which had abundant suspense-inducing deep bass. Considering their size, the KEFs reached unbelievable bass depths without a subwoofer. It was a surprising visual disconnect. In fact, I checked my sub to make sure it was not operating. Normally I would use a subwoofer for sound tracks with an LFE channel, but this was a good test of the KEF iQ50s and they clearly passed.
Lasting Impressions: Music
The iQ50s have a front mounted port or vent that comes with a removable foam plug in the event bass is too strong for personal listening preferences, but I did not find it necessary to use the plugs.
Moving beyond bass, the KEF iQ50s had a proportional, balanced quality that bespeaks a neutral sounding loudspeaker. Mids and vocals had a natural timbre and the upper ranges were detailed and accurate but averted any high-end sizzle or tizzyness that tends to wear on the ears and quickly results in listening fatigue. The KEFs delivered a delicate, relaxed listening experience, the kind that let's you enjoy music without the boom-sizzle. It's an excellent example of sound coherency and it makes casual and critical listening effortless and enjoyable.
Their compact size is unobtrusive and the fine fit and finish of the cabinets is impressive. With three finishes available, Black Ash, Dark Apple and American Walnut the iQ50s will blend easily with almost any room décor.
KEF recommends 15 – 130 watts for the iQ50s, but with a sensitivity specification of only 88 dB (relatively low), I would suggest an amp or receiver with 100 watts per channel or more to get the most dynamic range from the KEF iQ50s.