Product Review

KEF iQ7 Floor-Standing Speakers, iQ6c Center Channel Speaker, iQ8ds Surround Speakers, and PSW2500 Subwoofer

Part I

July, 2006

Piero Gabucci





● Three-Way

Power Handling: 150 Watts

Efficiency: 90 dB

Frequency Response: 40 Hz - 40 kHz

Nominal Impedance: 8 Ohms

● Dimensions: 8.7" H x 34" W x 12.9" D

Weight 32 Pounds/Each

● MSRP: $449.99 USA/Each



● Three-Way

Power Handling: 150 Watts

Efficiency: 90 dB

Frequency Response 65 Hz - 40 kHz

Nominal Impedance:  8 Ohms

● Dimensions: 20.1" H x 6.5" W x 10" D

Weight 19.6 Pounds

MSRP: $499.99 USA/Each



● Three-Way

Power Handling: 100 watts

Efficiency: 83 dB

Frequency Response: 65 Hz - 40 kHz

Nominal Impedance: 8 Ohms

Dimensions: 14.2" H x 37.1" W x 6.7" D

Weight: 11.5 Pounds

● MSRP: $299 USA/Each


     PSW2500 Subwoofer

● 12" Driver

Frequency Response: 33 Hz - 150 Hz

Amplifier 250 W

● MSRP: $599 USA


I have a soft spot in my heart for KEF Audio. Shortly after graduating from college, I'd rewarded myself with a pair of C40s loudspeakers. Easily driven, rated at 100wpc and 8 ohms, they offered what I thought was a great sound, especially for the price.

The C40s are modest by any standard, but the appeal to me was a warm natural sound and just enough detail without getting overly bright. We used those speakers faithfully on a daily basis when I was running everything we watched from television and VHS movies and two-channel CD and vinyl to boot.

I hadn't replaced the C40s since purchasing them in 1985, but I did frequent my favorite high-end shop from time to time just to see what KEF was doing. Although I still own them, I rarely have a chance to use them; I just can't part with them.

KEF (Kent Engineering & Foundry) is hardly new to the audio world, an English company originally founded in the early 60s. KEF successfully developed three-way designs with modestly sized cabinet units. In the late 80s, KEF developed the Uni-Q concept and it showed up in the reference loudspeaker, the 105. So Uni-Q is only new to the Q Series reviewed here.


I'm not sure what generation of Uni-Q is employed in the Q Series, there have been a few. But it represents a technology developed over the years, leading to what KEF refers to as "Acoustic Intelligence" in the new line.

Uni-Q technology, simply stated, is a 19mm (3/4") tweeter placed in the center of the midrange driver. KEF refers to this design as "co-incidental", technically not a driver, but an array. Typical driver arrays which have drivers separated or asymmetrical cannot pinpoint the accuracy of sound arriving at the same time especially at that sweet spot. Secondly, any listening outside the optimum range will invariably receive a muddy image.

KEF engineers feel this arrangement improves time alignment between drivers, paramount to the concept. Further, off-axis dispersion is said to be cleaner.

For the new Q series, KEF plates the cone of their Uni-Q driver with titanium metal in lieu of fabric or paper, which is said to maintain "mechanical integrity" to 20 kHz. With two magnetic circuits, Uni-Q employs a vented weight-saving die-cast aluminum chassis for both drivers.

The Design

The Q Series is a fully stocked speaker line capable of satisfying anyone's particular slant. It includes three loudspeaker, the iQ5, iQ7, and the reference iQ9. All are three-way bass reflex designs with the iQ9 adding a second 6-" LF woofer. If you prefer monitor-size, Q offers two models, the iQ1 and the iQ3, both two-way bass reflex. Likewise you have a choice from two center channel units, the iQ2c and the iQ6c. Lastly, if your preference is the wall-mounted dipole, KEF provides the iQ8ds.

The subwoofers that match this series are the PSW2500 and PSW3500. Besides the size, the difference between the two is a bit more power from 250 watts to 300 watts, and also a larger driver from 10" to 12".

The Q line is offered with four finishes: Black of course, Maple, and Apple (Cherry as far as I'm concerned) have been the popular choices of many speaker manufacturers lately. What was sent to me was the new finish Walnut, which I truly love. Not to get hung up on color, but this is truly a contemporary color and finish. I think KEF was right on with this finish in the current furniture market. Think IKEA or Crate and Barrel.

KEF North America kindly sent for my 5.1 review the iQ7s for fronts, the iQ6c for the center-channel, the iQ8ds for surrounds, and the PSW2500 powered subwoofer.

Click Here to Go to Part II.

Copyright 2006 Secrets of Home Theater & High Fidelity

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