KEF KHT6000 ACE 5.1-Channel Speaker System

In The Perfect Vision issue 57, KEF’s flagship KHT9000 ACE 5.1-channel speaker received a “Golden Eye” award as one of best sounding systems of its kind. That system was technically advanced and chock full of engineering innovations, and it combined sleek styling with uncompromised sound quality (a claim few “lifestyle” systems can make honestly). The only catch: at a price of $7400, the KHT9000 system exceeded many enthusiasts’ budgets, and I found myself wishing KEF would offer its impressive ACE technology in a less expensive package. With the introduction of its new KHT6000 ACE system, which starts at around $3700, KEF has done exactly that.

The KHT6000 system consists of four HTS6001 L/R/surround speakers, a horizontal-mount HTC6001 centerchannel speaker, and a PSW3500 powered subwoofer. The surrounds are essentially identical 3-way, 6-driver speakers housed in slender, roughly 23″-long enclosures with elliptical cross sections. Both feature KEF’s proprietary ACE technology (see sidebar, below), which gives small speakers essentially the same driver-loading characteristics as much larger ones; in practice, this means KEF’s compact L/R/C/surround speakers play louder and with much lower distortion than you might think possible. Pushing the envelope further, KEF offers ingenious “bass extender” floor stands that position the HTS6001s at ear level, but also act as bass-reflex cabinets that push bass response down to 75Hz (I wish KEF had positioned speaker binding posts on the tops—not the undersides—of these stands). Another ingenious touch is KEF’s HTS wallmount system (included), where wallmounts serve not only as support brackets but as plug-in wiring connectors that automatically select the wallposition EQ curves built into the HTS6001s’ crossovers networks. Completing the picture is KEF’s remote-control-equipped, 300W PSW3500 subwoofer, whose elliptical shape mirrors that of the HTS/HTC modules on a giant scale. The key question, of course, is whether this new system offers the same delightfully natural sound that was the hallmark of the KHT9000 design. The answer? An unqualified “Yes!”

KEF has a reputation for building speakers that deliver natural sound with low coloration and effortless, unforced clarity; the KHT6000 system upholds this tradition. In truth, I imagine some listeners might find the KHT6000 s y s t e m ‘ s n a t u r a l sound too s e l f – effacing or subd u e d ; at first, t h e s y s – t e m can seem less exciting or “spectacular” than competitors designed to create dramatic, colorful, vivid first impressions. Over time, though, the KHT6000 system grows on listeners specifically because it doesn’t impose a sound of its own; it is a true sonic chameleon whose rich palette of tone colors, timbres, and textures shifts to answer the demands of the music and film soundtracks you play. In short, you come to trust and then savor this system for its ability to tell you honestly how your material really sounds. TPV Editor Jonathan Valin calls this quality “transparency to the source,” and I think it is one of the KHT6000 system’s greatest strengths. The only downside is that the KEFs will also reveal any shortcomings your associated system components have, so choose wisely.

The KHT6000 system needs considerable break-in—40 hours or more—before it sounds its best. Initially, my review samples were bright, edgy, and dynamically compressed, but they loosened up beautifully over time, gradually becoming smoother, more focused, and more dynamically alive. So don’t be discouraged if your KHT6000s take a while to smooth out; the easygoing clarity you’ll enjoy later is well worth the wait.

Post break-in, the tonal balance of the KHT6000 system is quite neutral, with just the lightest touch of inviting warmth. Relative to the KHT9000 system, the KHT6000 system sounds actually a little cooler, just slightly more forward in the upper midrange, and a touch clearer and more analytical— though by no means sterile. In fact, the KHT6000 system may be more accurate than the KHT9000, though the larger system offers a pleasingly fullbodied sound that can help offset the occasional “iciness” of certain digital music recordings and film soundtracks. The KHT6000 and 9000 system subwoofers are cut from similar sonic cloth, offering a pleasing blend of low-frequency warmth, clarity, and extension. But where the KHT9000 sub is a big bass-reflex unit, KHT6000’s is a smaller, infinite-baffle design that deliberately sacrifices a few Hertz of low-frequency extension for more defined and tightly focused overall bass. This is a wise tradeoff; it makes the woofer much less fussy about room placement. One practical suggestion: For best sub-to-satellite integration, try using an 80Hz crossover frequency (slightly higher crossover frequencies might make sense on paper, but in practice they often make the system’s mid-bass sound too thick).

Like the KHT9000 rig, the KHT6000 system does a fine job with surround imaging and soundstaging, though the presentations of the systems are not identical. The KHT9000’s sound is characterized by smoothness and seemingly limitless dynamics, so that your overarching impression is that soundstages are big, spacious, and hold together well even at high volumes. The KHT6000’s sound, on the other hand, is characterized by broad dispersion, resolution, and focus, so that soundstages are deep and wide, with smooth yet very precise three-dimensional imaging. This was illustrated well by the multichannel SACD version of David Chesky’s Concerto for Flute and Orchestra as performed by the Area 31 ensemble [Chesky]. This striking composition features a rich, intoxicating blend of orchestral and percussion elements (some traditional and others not); and through the KHT6000 system, you’ll hear each instrument’s distinctive voice and dynamic signature, with instruments and performers precisely positioned within a huge threedimensional soundstage.

One tradeoff, however, is that when pushed hard the KHT6000 system eventually exhibits some coarsening of midrange textures and “splashiness” on hard transients, which are your cues to turn the volume down. Don’t get me wrong: the KHT6000 system offers great dynamics for its size and price (much better than competing “lifestyle” systems), but it understandably runs out of headroom well before the KHT9000 system does. Paradoxically, the KHT6000 system’s dynamics are so good, and its typical sound so clear, that you may sometimes feel tempted to turn the system up louder than you should.

The KEF system reproduces well-crafted film soundtracks beautifully, capturing the subtlest of inner details while taking blockbuster effects in stride (again, provided you don’t have volume levels cranked to the moon). One striking example occurs in the “Battle Stations” and “It All Turns Psychological” scenes from Wolfgang Petersen’s classic war film Das Boot [Columbia/Tristar, Director’s Cut Edition]. Here a British destroyer spots and attacks a German U-boat, as the submarine’s crew frantically, yet silently, strives to escape. On one level, the thunderous blasts of depth charges detonating nearby are impressive and terrifying, but the almost unbearable tension of these scenes derives just as much from the tersely whispered commands passed from the captain to his crew, the whir of machinery and the gurgling sounds of water as the sub maneuvers, and the ominous creaking of the hull as the submarine dives beyond its rated depth to avoid destruction. The KHT6000 system covers both ends of the spectrumthe big blasts on one end, and the frantic whispers on the other—with equal grace.

An important question: Can KEF’s “lifestyle”-oriented KHT6000 system hold its own in comparison to the best non-lifestyle speaker systems in its price range? Yes, it can—though some tradeoffs are, of course, involved. Von Schweikert’s comparably-priced System 12, for example, sounds smoother and can play louder than the KHT6000 system, but the KEF probably has better resolution and imaging. Similarly, Triangle’s Odyssey Major system sounds warmer and more dynamically alive, but the KEF is less colored and comes with a superior subwoofer. Indeed, the KEF system stands its sonic ground against stiff competition, while giving flat-panel display devotees the slim-line styling they crave.

To sum up, the KHT6000 system offers many of the virtues of KEF’s award-winning KHT9000 system at about half the price, and while it cannot match the big system’s sheer dynamic wallop, it does offer offsetting strengths in soundstaging and imaging precision. No other speaker system at this price offers more advanced technology, and none balances the “looks cool/sounds good” equation more effectively, so that I’ve got just one word for the KHT6000 system: Bargain.