The Short Form

$2,498 a pair / KLIPSCH.COM / 800-554-7724

Snapshot

Klipsch's slim, sexy-looking, full-range, fully powered design scores high marks

Plus

• Deep, precise imaging with large sweet spot • Surprising bass extension mitigates need for sub (in stereo music systems) • Knockout looks

Minus

• Response accuracy compromised by near-wall placement

Key Features

• Vented enclosure (via dual passive-radiators) • (2) 5 1⁄4-in woofers; 3⁄4-in titanium-diaphragm high-frequency compression driver • Active speaker powered by 110-watt amplifier • Line- and speaker-level inputs • Line-in sensitivity and auto-on/off switches • Removable power cord • 48 3⁄4 in high (w/base); 39 lb KLIPSCH.COM :: 800-554-7724

Klipsch began making high-performance speakers well before the advent of the transistor, so when it unveils an all-new flagship design, the world pays attention. Topping the company's Icon line, the XF-48 is a departure for Klipsch for several reasons. It's slim and very well dressed, with a gloss-lacquer finish and compound-curving "cheekbone" angles to its aluminum enclosure. It has a pair of oval passive-radiator diaphragms (no doubt in the interest of the aforementioned slimness). And it boasts an all-new horn-tweeter design. Most unusual of all, the XF-48 is an active full-range speaker — which means that all of the necessary amplification, custom tailored to its woofers and tweeter, is contained within the speaker itself.

Any engineer (or Vulcan) will tell you that active is the only logical speaker design. The advantages are many. Without wasting silicon (or dollars) on excess, you can ensure that each driver gets all the power it can handle. You can incorporate predetermined equalization and processing to help optimize performance and extend response. And since each driver is powered with just the frequency range it reproduces, you can kiss off the power-sucking, distortion-inducing passive crossover network required by virtually every conventional speaker. Active speakers have liabilities, too, but the situation mostly boils down to this: They're hard to sell. For whatever reasons, Americans like to choose their speakers and receivers (or amplifiers) independently.

SETUP

Initial placement of the XF-48s was a mere matter of wrestling them out of their l-o-o-o-ng boxes and putting them 9 feet apart and 8 feet from my listening position. Hookup was simple: A line-level (RCA-plug) cable went from each speaker to my preamp/processor's line outputs, and wall current was delivered via the supplied removable power cords.

There are speaker-level inputs (in case your processor or receiver lacks preamp outputs) plus mini toggles for high/low-input sensitivity and to enable the Icon's auto on/off circuitry. There's no way to individually balance the XF-48's low- and high-frequency amps — perfectly sensible, since unlike "power tower" designs with active-subwoofer-only sections, the Icon's low-frequency side covers the full bass-to-midrange spectrum.

The new tweeter horn (with integral lens or waveguide) has a claimed 80° x 80° dispersion pattern, and the horn's unusual, petal-like form serves a 3⁄4-inch compression driver — essentially, a tweeter engineered to mate with a horn. A controlled, consistent sound spread is the hallmark of horns, and the XF-48's output was indeed impressively even over a substantial horizontal range, maybe as much as 30°. The vertical sweet spot was a lot narrower — no doubt due to the drivers in the dual-midwoofer array being placed one above the other, an arrangement that's well known to restrict vertical dispersion, thereby reducing primary reflections.

Fine-tuning the placement of the Icons took a bit more work than I'd anticipated. I started out with the speakers hard against the wall behind them, with their grilles more or less on the same plane as my Samsung LCD TV. This seemed logical enough for a speaker that, visually at least, appears designed to match flat-panel TVs. But the sonic result was subpar: Bass was ample but a bit muddy and ill-defined, and there was a boosted, slightly tubby cast to male vocals — precisely what I'd expect from any conventional floorstanding speaker thus located.

Since I knew this couldn't be what Klipsch had in mind, I pulled out the Icons a couple of feet from the wall. Big improvement, though still a bit thick through the octave from the upper bass to the lower mids. So I pulled them out another 18 inches. Now we're talking!

In their final position, the XF-48s still came across a little warm, but the sound was open, balanced, and natural right across the midrange octaves. The top three octaves or so were more relaxed than I might have predicted, given Klipsch's tradition of crisp (even bright) voicing. But the treble was extended and generally well defined nonetheless.

This combination of sonic traits makes strings sound irresistibly gorgeous on the XF-48s. Case in point: the Smithsonian Chamber Players' Sony Classical/Vivarte recording of an octet by Louis Spohr (a much overlooked contemporary of Beethoven), with the Players on Stradivarius instruments from the museum's collection. Here, the sound was rich, rosiny, and generously detailed. It had a lifelike bite on strong attacks and a deep, resonant, woody sense of air around and behind each musician.

In today's multichannel age, it can be easy to forget just how much magic can be wrought by a single pair of speakers and a great stereo recording. Listening to the Reference Recordings disc of Eiji Oue conducting the Minnesota Orchestra in three works by Stravinsky refreshed my memory as to the depth, detail, and musical color that stereo can convey. The Icons performed admirably with challenging, full-range material like The Song of the Nightingale, producing smooth but exciting big-hall sound with ample slam on big-bass attacks.

So, do the XF-48s require a subwoofer? For most music listening, no. They produced, for example, the strong low "F" (43 Hz) on the opening notes of Feist's "Tout Doucement" without strain and with no loss of heft or loudness as compared to my everyday system, which includes a costly 12-inch sub. The speaker's low end was fairly even, moderately dynamic, and well defined, but with a touch of middle-bass emphasis that gave plucked jazz bass and similar instruments a warm, round tone.

The Icons could also play impressively loud. When I let loose with the 2002 remaster of Supertramp's Breakfast in America, I found that the speakers retained surprising punch and bass impact at fairly lease-breaking levels. When the Icons were pushed into rock-concert territory, dynamics began to flatten noticeably, and they became "shouty" in the vocal ranges, but they still didn't break up or otherwise overtly distort; this was well past the point I'd choose to undergo for more than 16 bars or so. Klipsch's rather terse specs volunteer only that each speaker's onboard wattage is "110 watts," and that its low-frequency amp is Class D (a "digital" amplifier) and the tweeter side is a Class A/B circuit. Whatever — I say it was enough.

MOVIE PERFORMANCE

In the name of science, I inserted the Icons into my multichannel layout, using my long-term center and surround speakers and amp. I then ran the system through a battery of film-sound hurdles from titles including Pearl Harbor and Master and Commander. Suffice it to say that the XF-48s delivered clear, punchy sound and plenty of output. They generated enough low-end grunt for satisfying movie sound, but for true high-end home theater, a subwoofer is certainly called for. Klipsch's XW-500d ($999), a compact 10-inch model, seems a likely candidate and will be available by the time you read this.

BOTTOM LINE

Klipsch's Icon XF-48 is an extremely able, extremely slim, and extremely good-looking powered speaker. And it's priced very fairly if you factor in the sums that would be otherwise spent on an external amp. Fans of serious sound who are unafraid to veer away from the passive-speaker herd — Icon-oclasts, if you will — should absolutely seek out the XF-48 for a listen.

TEST BENCH

The curve for the XF-48 reflects response with the speaker standing on the floor, averaged over a ±30° window. All measurements were taken at a full 2 meters. This emulates a typical listening distance, allows larger speakers to fully integrate acoustically, and (unlike near-field measurements) fully includes front-panel reflections and cabinet diffraction. The primary characteristic of the XF-48 is a 6- to 8-dB reduction in response below 300 Hz and a series of narrow-band irregularities above 800 Hz that increase in severity and width with increases in frequency. When its Sensitivity adjustment is switched to Low, the speaker’s basic level drops by 10 dB. — Tom Nousaine