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KEF Q Series Speakers Review

The KEF Q Series is a bit of a minor miracle, really: an incredibly affordable, high-performance sound system that adapts itself (sonically, at least) to any room.

Is every home theater speaker system you install a completely architectural affair? In-wall, in-ceiling, behind-screen, whatever? If so, this is a review that you can pretty safely skip, because KEF’s new Q Series speakers are none of the above. They’re big, bulky boxes. They’re kinda obtrusive, despite being quite attractive. And they come in a grand total of four finishes. So, why write about them in a publication aimed squarely at the custom integration market? For the simple reason that of all the traditional boxy speakers I’ve reviewed in the past few years, the Q Series lineup is one of the most flexible and installer-friendly I can think of off the top of my head.

KEF’s Q Series family of speakers in the walnut finish

Before we dig into it all, though, let’s talk about the Q Series from a high-level perspective. At its heart, this new lineup represents a real-world application of the things KEF learned from the development of its massive Blade speakers, in a scaled-down, more-attainable form that pretty much anyone can afford. In its cheapest configuration, including four of the smallest Q100 bookshelf speakers, the Q200C center speaker, and Q400b sub, a basic 5.1 system runs in the neighborhood of $2,300 retail, though with two different bookshelf offerings, three floor-standing towers, two different center speakers, and a dipole surround speaker in the lineup, it goes without saying that total system price varies greatly depending on the needs of the room.

One thing that all of the speakers in the Q Series have in common (except for the subwoofer, of course) is their Uni-Q driver: in this case, a complete reworking of KEF’s trademark driver, comprised of a 5.25-, 6.5-, or 8-inch aluminum cone and 1-inch (or, in the case of the Q900, 1.5-inch) vented aluminum dome tweeter in a concentric array. The Q900 has the largest Uni-Q driver KEF makes. It is an 8-inch aluminum cone with a 1.5- inch tweeter. Among their differences: the fact that all of the tower speakers sport a 2.5-way bass design with passive radiators, the bookshelves feature a two-way bass reflex design with front ports, and the center speakers are both full, three-way bass reflex, again with passive radiators. (The Q800ds dipole, which isn’t being reviewed here, is the one standout in the lineup, in that it’s a three-way design with no ports or passive radiators.)

So, what’s so custom about all of that? Well, firstly, all of the speakers in the Q Series line can be biamped, but if you’re having visions of kludgey jumpers (that are likely to be lost) at the mere mention of such, clear them from your mind. Each Q Series speaker actually includes a pair of knobs between their pairs of binding posts, with a label between them that reads “Link.” It’s self-explanatory enough: if you want to biamp a speaker, simply twist the knobs counterclockwise to unlink the binding posts. If you don’t, twist them clockwise to link them. It simply couldn’t be any easier or more elegant.

Q100 Bookshelf Speaker

Secondly, the ported speakers in the line (the Q100 and Q300 bookshelves, that is) come complete with foam port plugs in the box, allowing you to tune the speakers to your liking. What’s more, the ports are front firing, which relieves a lot of stress when it comes time to position the things in room. The test system that KEF sent me for evaluation included both the Q100 and Q300 (a pair each), and I found both to be ridiculously forgiving in terms of placement, especially in regard to distance from the walls behind them.

Really, though, the entire Q Series line is an exercise in forgiving speaker placement. In my bedroom home theater system, where I did the bulk of my testing with these speakers, I have a bit of an unfortunate situation where my right surround speaker sits a couple of inches lower than the left, and it isn’t exactly easy to position them symmetrically, at least not permanently. As such, I generally have to reposition any speaker system I’m reviewing in this room temporarily, into somewhat less-than-convenient locations, only to move them back to less obtrusive spots when I’m done listening critically. It’s that, or get yelled at come bedtime.

That juggling really wasn’t necessary with the KEF Q Series. As long as they were roughly in the neighborhood of the right location, the entire system sounded fantastic—open, even, and utterly enveloping. What’s more, the center speaker sounded incredible from pretty much any spot in the room, with none of the lobing or “picket fence effect” normally heard with larger center-channel speakers. No matter where I wandered in the room, dialogue was exceedingly intelligible, even with the densest and most difficult soundtracks, like the Mines of Moria sequence from Lord of the Rings: The Fellowship of the Ring. In fact, if there’s one word that describes the sound of this system better than any other, it’s “clarity.”

And that’s without the benefit of any room correction, above 250Hz or thereabouts. Generally speaking, when I run Anthem Room Correction on speakers in this room, I let it do its thing up to around 600Hz (sometimes as high as 1kHz, and in some rare instances all the way up to 5kHz). The KEF Q Series is so balanced and neutral, though, that nonesuch was necessary, above and beyond dealing with a few standing-wave issues with the bass.

Speaking of bass, the KEF Q400b sub probably wouldn’t revolutionize the market on its own as a standalone offering, but as part of the larger Q Series package it’s a pretty stunning performer. In terms of controls, it gives you variable level and crossover knobs, as well as switches for phase (0 or 180 degrees) and EQ (a 0, 6, or 12dB boost at 40Hz), along with a phoenix connector for speaker level inputs. For a sub this small, though (it features a single 10-inch driver and a sealed design), it delivers some deliciously deep bass. KEF rates its low-frequency extension as 28Hz, which is more than respectable for a sub of its size. That doesn’t tell the entire story, though, because the Q400b’s roll-off on the lower end is as shallow and graceful as I’ve seen in a sub for quite some time. In my room, yes, the 3dB-down point is somewhere in the vicinity of 28Hz. But the 6dBdown point is closer to 22Hz. And yes, it may lack a little in terms of punch, but there’s still plenty of audible energy down in the neighborhood of 17 or 18Hz–without a hint of audible distortion. As such, the sub’s reach is deep indeed, yet it doesn’t struggle in the slightest to cross over with the rest of the speakers.

Taken as a whole, the KEF Q Series is a bit of a minor miracle, really: an incredibly affordable, high-performance sound system that adapts itself (sonically, at least) to any room. Assuming, of course, that you actually have room for it.


The KEF Q Series’ concentric Uni-Q drivers deliver incredible clarity, exceptional dispersion, and wonderful neutrality, making them super easy to place in virtually any room. Frankly put, they’re a stunning value.

Even the smallest speakers in the lineup are quite large, though, so be sure you have the space for them. What’s more, the limited finish options may cause you some conflicts in projects where you have to work with an interior designer.

Product Specs

Q300 Bookshelf Speaker
► D esign: Two-way bass reflex
► Drive units:
– 165mm (6.5in.) aluminium Uni-Q
– 25mm (1in.) vented aluminium dome HF
► Frequency response: 42Hz – 40kHz (±3dB)

Q100 Bookshelf Speaker
► Design: Two-way bass reflex
► Drive units:
– 130mm (5.2in.) aluminium Uni-Q
– 25mm (1in.) vented aluminium dome HF
► Frequency response: 49Hz – 40kHz (±3dB)

Q600c Centre Channel Speaker
► Design: Three-way bass reflex
► Drive units:
– 165mm (6.5in.) aluminium Uni-Q
– 25mm (1in.) vented aluminium dome HF
– 165mm (6.5in.) aluminium LF
– 165mm (6.5in.) aluminium ABR
► Frequency response: 45Hz – 40kHz (±3dB)

Q400b Subwoofer
► Design: Closed-box subwoofer
► Drive unit: 1 x 250mm (10in.)
► Frequency response: 28Hz – 140Hz (±3dB)