Product Review

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

Part II

July, 2006

Piero Gabucci



iQ7 Floor-standing Speakers

The iQ7 floor-standing speakers were a bit smaller than I had anticipated, but it was no problem. In fact, I immediately appreciated their "placement friendly" size and weight: about 34" tall and weighing 32 pounds each. Narrow, at less than 9" wide, it's quite deep to make up the volume almost 13" deep. The beauty of the finish wraps the entire enclosure. The rear sensual curve is uncluttered save the binding posts near the bottom. Capable of both bi-wiring and bi-amping, the posts are supplied with removable jumper cables.

The top of the speaker has a slight bulge where the main 6 " Uni-Q driver is raised. KEF refers to it as a pod, fairing with the logo-etched plastic top plate covering the Uni-Q driver.

Constructed of very rigid MDF, the asymmetrical oval cabinet reduces distortion. As I mentioned, the unit is quite light, yet I found it remarkably solid. The speaker is provided with carpet spikes, and I was able to easily move them around because of their light weight.

The iQ7 is an 8 ohm speaker capable of handling up to 150 watts and has a high sensitivity rating of 90 dB. Frequency response is from 38 Hz - 40 kHz. The crossover frequencies are at 250 Hz and 2.8 kHz.

A second impressive 6 " woofer driver is set below the Uni-Q. A "natural fibre" paper cone with roll rubber surrounds allows for the cone to have a greater range of motion. KEF refers to it as the "LF" unit. You'll notice the integrated and self housed port for the LF driver, complete with removable foam insert (for bass alteration).

iQ6c Center Channel Speaker

This speaker is also a three-way bass reflex unit, with an elegant front curve. Functionally, the wide curve gives the three drivers an angle that increases room dispersion. The 5 " Uni-Q driver is flanked by 5 " LF paper cone drivers. The rear has a single port that's located off center.

Very similar to the iQ7s, the iQ6c can handle 150 watts and has a sensitivity of 90 dB.

iQ8ds Surrounds

The dipole surround units have a pair of 5 " Uni-Q drivers, facing at 900 to each other. Boxy in shape, yet still with that slight front curve common throughout the Q Series lineup, the 8 ohm iQ8ds weighs over 11 pounds, and is about 7" tall, 14" wide, and almost 7" deep. Mounting is done with recessed mounting brackets. The frequency response is between 65 Hz and 40 kHz but offers a much lower sensitivity at 83 dB.

PSW2500 Powered Subwoofer

Echoing the oval, or should I say elliptical design of the iQ series, the KEF 2500 is probably the most attractive full-sized subwoofer I've seen. I'll admit I'm a minimalist, and the sub in question takes a simple idea, and extrudes the elliptical shape beautifully. I'd almost argue it's more of a "lifestyle" piece, and I mean that with the highest respect.

Aesthetics aside, the sealed unit PSW2500 has a 250 watt amplifier pushing a 10" down-firing "ultra long throw" driver. Standing about 14" high, its breath is almost 20", and very much like the iQ7 floor-standing speakers, this sub is surprisingly lightweight at less than 32 pounds.

A point of interest might be the included manual for the 2500, written in 8 languages, it aids in set-up and troubleshooting.

The rear has the usual array of controls for a quality subwoofer: an On/Off switch (active produces a green glow), Phase, Volume, and Auto On feature.

It also includes uniquely a Ground Lift, a Music/Cinema switch (Music is said to give a deeper bass), and Slope control, adjusting the transition from speakers to subwoofer at either 12 or 24 dB.

The KEF sub includes line level inputs and high pass outputs for left/right main speakers.

Able to run from both 230v or 115v power source, the 2500 has a removable power cord.


The biggest surprise for me was the PSW2500 subwoofer. This unit has tremendous potential, yet it requires taming. Placing this oval unit is critical to finding its best performance; patiently I finally found the right location and settings to satisfy me. It sounded best away from corners and slightly off the side wall.

The main iQ7s needed some attention to placement as well, which also surprised me. Usually I find rear ported loudspeakers need special attention to placement. Since only the center iQ6c is rear ported, the iQ7s should not have been affected. Placing them about three feet of the rear wall and keeping them away from sidewalls produced the most enjoyable sound. I also found spacing them a bit further apart dramatically improved the spatial imaging. Although my space is a bit tight to begin with, I managed to keep them about seven feet apart; I would have liked another foot.

Placing the surrounds was limiting due to their wall-mounted dipole design, so taking advantage of the iQ8ds potential presents a challenge if your rear wall is not ideal. Secondly, it was nearly impossible to wall mount these units (WAF), so I placed them on stands about three feet tall.

My varied reference equipment included Denon and Integra receivers. Both were used directly and as preamps through a Rotel five-channel amplifier. I also combined the Maestro M2 SSP with the Rotel amp, a killer setup. On hand for two-channel fun was the Onix H6550 50 wpc integrated amp. I used the Denon DVD-2910 for both music and movies and also the Onix XCD-88 CD player.

I endorse taking advantage of bi-wiring the iQ7 and iQ6c center channel; in fact I was delighted by the difference. So do keep in mind all evaluation was completed in this form.

All cabling was Ethereal.

Click Here to Go to Part III.

Copyright 2006 Secrets of Home Theater & High Fidelity

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