KEF reserves the right, in line with continuing research and development, to amend or change specifications. E&OE.
If you're an audiophile with the means, you'll do well to look at the KEF X300A ($799.99 direct). It's an ideal pair of speakers for an apartment, office, or study, and it includes a digital USB connection for improved, all-digital sound when connected to a PC or Mac, bypassing your computer's internal sound chipset in the process. There's no wireless Bluetooth or AirPlay support, although you can plug in an iPad, Android device, or other mobile gadget using the 3.5mm auxiliary input, and you can also connect the X300A to an Apple AirPort Express ($99) for wireless listening from AirPlay-compatible devices. The KEF X300A isn't inexpensive by any means, but for a powered desktop speaker system in this price range, it's as close to perfect as we've heard—and a clear Editors' Choice.
Design and Setup
Even if you didn't see the price tag, there's no chance the KEF X300A£678.17 at Thomann will be mistaken for an inexpensive speaker system. Each robust X300A enclosure measures 11 by 7.1 by 8.5 inches (HWD) and weighs a solid 16.5 pounds. They come in a snazzy textured dark gray finish with rounded edges, along with a matte black front panel. The rear of each enclosure features a prominent heat sink that adds another 1.1 inches to the depth figure, for a total of 9.6 inches.
The X300A is a two-way bass reflex design with a 5.25-inch magnesium and aluminum alloy woofer and a 1-inch vented aluminum dome tweeter. The wide-dispersion Uni-Q driver array, with the tweeter positioned in the center of the woofer cone, is a classic KEF trademark and similar to the one in KEF's $30,000 Blade system. There are no speaker grilles, so the driver array is always on full display, and in my opinion at least, it looks really sharp.
Each speaker has its own grounded AC power outlet and cord; you'll need two wall outlets to power the X300A, just like you would with active studio monitor speakers like the M-Audio BX5 D2$299.95 at zZounds. The left speaker contains the main volume control knob, but it's on the back and difficult to reach. To control volume on a day-to-day basis, you're supposed to use the software volume control that's built into your PC or Mac. Also on the back panel is a switch that selects between "desk" and "stand" (or free space) placement, and KEF provides a pair of baffles in the box you can use to plug up the rear-facing ports if you plan on positioning the speakers close to a wall.
The built-in USB connection is fairly novel. While speakers have been doing that for a little over a decade now—the original version of what is now the Harman Kardon SoundSticks III$169.95 at Harman Kardon had this type of connection—it still makes sense if you want the best possible sound quality, especially thanks to the X300A's 96kHz/24-bit digital-to-analog (D/A) converter.
The package actually includes two mini-USB-to-USB cables; one connects the two speakers to each other, while the other connects the left speaker to your computer's USB port. Once you've made these two connections, plug both speakers into the wall, power up the left speaker using the switch on the back, and you're ready to go. A standby mode kicks in whenever the speaker hasn't been used for more than a few minutes, which helps keep your power bills down.
Our test Apple iMac 27-inch$1,849.99 at B&H Photo-Video computer recognized the X300A immediately, both for default audio listening in iTunes, and for monitoring recording in Logic Pro X. For the latter, I found I had to turn off the speakers to re-enable headphone listening, which then caused Logic to reload my current project, as it treated the X300A like a new audio interface; not a big deal, but something to give thought to if you're thinking of using the KEF X300A as a pair of studio monitors. I also tested the X300A with a Lenovo ThinkPad laptop running Windows 7; the system recognized the X300A and installed drivers on its own, and everything played perfectly as a result.
Performance and Conclusions
Each X300A speaker includes twin class-AB amplifiers: a 20-watt unit for the tweeter and a 50-watt amp for the magnesium woofer, as well as the aforementioned DAC. KEF rates the X300A at 58Hz to 28kHz, plus or minus 3dB, and 49Hz to 45kHz, plus or minus 6dB. That -6dB point is pretty good for a small bookshelf speaker, and KEF claims a maximum output level of 104dB. Unfortunately, there's no way to add a powered subwoofer to the system, but chances are you won't miss it unless you're watching blockbuster movies or playing games on your PC.
In a variety of music listening tests, the X300As sound exemplary. The best part about the sound is the smoothness in the high-mids. Other parts of the frequency spectrum also sound great, but there's something about the immediacy and level of detail you hear in the X300A that's beguiling, and that shows up the limitations in the crossover region you'll hear on lesser speakers. For example, in Ani DiFranco's "Knuckle Down," you get every last noise on the acoustic guitar strings from her pick work, with a palpable sense of the guitar's body that can get lost on speakers that stumble on all of the treble information.
Whenever you hear a speaker like this, with its bright, clear presentation, you might worry that the tweeters will sear your ears off on hard rock or metal music, but that's not what happens here at all. With Rage Against the Machine's "Fistful of Steel," the X300A delivered punchy, energetic guitars and super-smooth hi-hats and crash cymbals. You could say the X300A's frequency response curve leans a bit bright, but it's never unpleasant. Still, perhaps as a result, the X300A does particularly well with classical music, such as John Adams' "The Chairman Dances," which is full of high strings and brass that really show off the X300A's high-resolution midrange and treble performance.
Imogen Heap's "Headlock" is another showpiece for these speakers, with its warm-sounding cello, sparkling electronic synths, occasional deep bass notes, and beautiful, breathy vocals. Flunk's "Indian Rope Trick," an electronic chill-out track, sounded bright and airy—perhaps a bit too much so, albeit without any trace of harshness. I also listened to Depeche Mode's "Suffer Well," which through the X300A exhibited a kick drum, while not as deep as I've heard on systems with a powered subwoofer, was still plenty strong. In all cases, it's easy hear the difference the pristine digital connection and built-in D/A converters affords, compared with, say, the inferior 3.5mm input analog jack on a low-end PC laptop.
You're going to have a tough time finding a powered speaker system better than the X300A at this price. Our favorite 2.1 system, the Paradigm Millennia CT, costs $100 less and has the deep, almost subterranean bass extension you get with a proper powered subwoofer, but lacks the all-important digital connection and easier placement you get with the X300A. The Audioengine 5+$399.99 at Crutchfield, meanwhile, offers much of the same excellent performance, although it's not quite as refined-sounding, and it lacks a digital USB connection. The M-Audio AV 40$159.99 at OWC is the least expensive speaker I'd recommend in this 2.0 configuration, but it doesn't approach the detail or sheer output power of the X300A. All told, for its thrilling and uncolored sound, without the placement and crossover complexities of a 2.1 system, and with a pure digital connection, the X300A is our new Editors' Choice for desktop PC speakers.