Note: measurements taken in the anechoic chamber at Canada's National Research Council can be found through this link.

In November 2020, Focal announced a special-edition update to its Aria line with the Aria K2 936 loudspeaker, which Doug Schneider reviewed on this site in May 2021. The three-way floorstander was an update to the existing 936 model (which is still available), with side panels in the high-gloss Ash Grey finish from the flagship Utopia line and K2 cones in place of the Aria line’s usual flax-based midrange and woofer cones. According to Focal’s website, K2 cones are “composed of a very light foam layer, between a layer of aramid fibres and a layer of fibreglass, ensuring clear and precise sound void of any colouration.”

The company featured its K2 cones in the Spectral 40th floorstander, which I reviewed on this site in September 2019. The size of the speakers made them a pain to lug down to my basement listening room, but I absolutely adored listening to them. Now, Focal has decided to round out the line with the Aria K2 Center ($1299, all prices in USD) and K2 906 ($2398/pair), the latter being the subject of this review. Based on the existing Aria Center and 906 models, these new speakers have also been upgraded with the Ash Grey side panels and K2 cone material. After my experience with the Spectral 40th floorstander, I was excited to be asked to review another Focal K2-based design—this time in a two-way standmounted model that, at 19 pounds, is smaller and more back-friendly.

Description

The K2 906 is made in France, as are all Focal’s home hi-fi speakers. Its cabinet measures 15.4″H × 8.9″W × 11″D and is constructed mostly from MDF. The speaker’s top and bottom are flat panels in a parallel alignment. Ditto for the front and back panels. But the tapered Ash Grey side panels are curved where they join the front panel and narrow as they extend to the rear, which gives the speaker an attractive shape. To add to the decoration, the top panel is finished with a black-colored glass plate, while the front, rear, and bottom panels of the cabinet are clad in black faux leather, which I thought complemented the look of the side panels nicely. The bottom panel has four threaded inserts that can be used to attach the speaker to the matching Aria S900 stand ($589/pair).

A little more has to be said about the appearance. Unlike many high-priced speakers out there, but very much like Focal’s most expensive Utopia and Sopra lines, the K2 906 looks modular—that is to say, it does not appear, or even attempt to fool the observer into thinking, that the cabinet is one solid, continuous sculpture. Rather, it’s quite clear that the side panels are distinct from the front baffle, which is distinct from the top panel, and so on. This does not take away from the aesthetic appeal of the speakers; I found the speakers easy to look at in my room. I also liked their exacting, top-notch build quality—everything appeared to fit together perfectly.

The K2 906’s 6.5″ midrange-woofer features the above-mentioned K2 sandwich cone. The history of aramid/foam sandwich cones at Focal goes back to 1986. The technology was first introduced for the company’s long-since-discontinued Vega and Antea speakers. It was then known as the Poly-K cone, and comprised a hollow microball structure with two outer layers of aramid fibers (hence the distinctive yellow color). In 2016, Focal refined and evolved this technology, and the resulting K2 cone is now constructed from a very light foam sandwiched between a layer of aramid fibers and a layer of fiberglass.

The midrange-woofer crosses over to Focal’s TNF tweeter at 2.8kHz. The 1″ TNF tweeter has an aluminum-magnesium inverted-dome diaphragm. Focal claims that the inverted dome’s spatial characteristics and very low directivity make it superior to the conventional domes used by the company’s competitors. The suspension between the dome and its bracket uses Poron, a urethane foam material with shape memory. This suspension method is directly derived from the company’s Utopia Beryllium tweeter, and Focal claims it can reduce distortion by a factor of three in the 2–3kHz range. To further improve the performance of the tweeter, it has been fitted with a urethane waveguide that directs the output to enhance horizontal dispersion. Below the midrange-woofer is an aerodynamically shaped, low-distortion port.

The frequency response of the K2 906 is rated at 55Hz–28kHz (±3dB), the sensitivity at 89.5dB (2.83V/1m), and the impedance at a nominal 8 ohms (minimum 4.6 ohms). Recommended amplifier power is 30–120Wpc, and Focal suggests that the K2 906 be used in listening rooms of about 160 square feet, with the listener about 8′ from the speakers.

Setup

The pair of K2 906 speakers came packed in one large box, along with an instruction manual and magnetic grilles, each wrapped in a nice cloth bag. I left the grilles off for all of my listening because they rarely do anything to enhance the sound. I placed the speakers atop my 24″ Focal Sopra No1 stands (I own Sopra No1 speakers, which are priced at $11,998/pair) in my usual configuration, with the speakers forming a 9′ equilateral triangle with my listening chair. I experimented with toe-in angle to see if my usual 15 degrees or so would be optimal—it was. A little less toe-in and image size and specificity suffered. The backs of the speaker cabinets were about 24″ from the wall behind them.

My listening room is a relatively small (15′ × 12′) dedicated space, treated with broadband absorption at the first reflection points and on the long wall behind the speakers. There are homemade bass traps in the front corners. I connected the K2 906 standmounts to my McIntosh Laboratory MC302 amp using 12-gauge oxygen-free copper speaker wires terminated with locking banana plugs I soldered on myself. I used my Bluesound Node 2i as the digital source, connected to the S/PDIF coaxial input on my McIntosh C47 preamplifier-DAC, which, in turn, fed my amp via balanced Monoprice interconnects. The Node 2i was configured as a Roon endpoint, and I controlled the Roon application—running on a dedicated Windows 10 laptop connected via Ethernet to my network—with the Roon Remote app installed on my Microsoft Surface Pro 6. The music was supplied by Qobuz and my ripped (to FLAC) CD library stored on a Synology NAS.

Sound

After letting the Arias break in for about 24 hours, I sat down to listen critically. First up, Tracy Chapman’s “Fast Car,” from her self-titled debut album (16-bit/44.1kHz FLAC, Elektra Records)—a great track for evaluating speakers. From the moment Chapman’s voice enters the mix, I recognized that glorious Focal midrange I’ve come to love. As her vocal image hung in a well-defined space, dead center and slightly behind and above the speaker plane, I could feel the rich tonality of her voice as she sang the words. It was smooth, full-bodied, open, and free of the cabinets. When I focused on the cymbal crashes placed hard left and right on the soundstage, I smiled; as with the midrange, I found nothing to reprimand these French speakers for. I heard extension and long decays, along with refined microdetail approaching the performance of my far-more-expensive Sopra No1s, which sport Focal’s statement-level beryllium inverted-dome tweeters.

Next, I focused on bass performance using Blues Traveler’s “Run-Around,” from Four (16/44.1 FLAC, A&M Records). This track is fast-paced, with toe-tapping, punchy bass. I won’t say that the Focals necessarily disappointed in the lower registers, but I was left somewhat wanting in that regard. I heard quick and nimble bass, with good pitch delineation that allowed me to zero in on the kick drum and bass guitar separately, but there wasn’t quite enough energy for my liking.

Pausing my subjective listening, I measured the in-room averaged frequency-response with my calibrated miniDSP UMIK-1 microphone and Room EQ Wizard, and found that, relative to 2kHz, the -3dB point was at 34Hz. In terms of extension, this is an above average result for a two-way speaker of this size, in this position in my room. The other noteworthy observation from the in-room bass frequency response, however, was the amount of bass boost the speakers exhibited. Between 50 and 80Hz, there was only an extra 3–5dB of boost relative to 1kHz. This is decidedly less than what many two-way speakers of this size yield in my room, and corroborates the slightly depressed bass output and impact I had heard from the Aria K2s.

For something harder-hitting and a little more raucous, I turned to Slash’s 2010 version of “Paradise City,” from Slash (16/44.1 FLAC, Universal Music), a collaboration with Fergie and Cypress Hill that fits the bill for being loud, frenetic, and dense. While the slight lack of bass output was evident on this track, the rest of the musical experience was exhilarating and satisfying. I played this track fairly loud, reaching peaks of 95dB SPL at the listening position (C-weighted), to see if the little Focals could remain composed and clean-sounding. At the 23-second mark, when the lead, rhythm, and bass guitars are at full throttle, and the kick drum is slamming away, the Aria K2 906 standmounts sounded crystal clear and squeaky clean; I could hear and follow all the changes in tone, speed, and layering from all the guitars at play during this very busy sequence. And when Fergie’s voice enters the mix, it floated freely above the wall of sound in a pocket of air. The high frequencies were, as with the Chapman track, well balanced, with good attack and long decays—never sounding dull or too aggressive.

I then turned to a track I often use to evaluate speaker transparency, which relates to the clarity of a speaker and how well it projects sound without calling attention to itself. Colin James’s “National Steel,” from National Steel (16/44.1 FLAC, Warner Music Canada), is a well-recorded, minimalist track that is an excellent test for this attribute. The tune opens with two guitars, one centered at the back of the stage, the other off to the left and closer to the front. On this track, I like to focus on the reverberation of the strings during the attacks and decays, to see if the sounds remain focused in space, or if subtle cabinet resonances “link” the aural image back to the speaker, muddying the sound and hindering the illusion of realism. I can say without hesitation that the Focals did not disappoint in this category. They placed the guitar plucks authoritatively, with attacks and decays confined to well-defined aural bubbles that hung in free space—it sounded very real indeed.

After living with my own pair of Focal speakers, and hearing many more of the company’s models, I attribute much of my admiration for this French brand to the way its speakers reproduce voices. James’s vocal on this track was no exception. I experienced a sense of corporeality that was a real treat—his voice had a rich meatiness, without sounding thick or chesty. This pleasing tonality was coupled with exquisite detail retrieval, with every breath and shift in intonation laid bare for me to enjoy. Well done, Focal, no complaints here!

Comparison

I made level-matched comparisons between the Focal Aria K2 906 speakers and a pair of Revel Performa M126Be standmounts, which cost $4400 for the pair. That’s a big price difference—almost double—but the Focals performed to such a high level in my room that I wanted to compare them with true reference-grade standmounts.

The two speakers have a similar driver complement—the M126Be has a 6.5″ midrange-woofer and a 1″ tweeter, though its tweeter has a beryllium dome. I used pink noise and an SPL meter and found the Focals to be 1.5dB more sensitive in my room, so I adjusted the volume accordingly for each comparison using Roon’s headroom-management feature.

Overall, both pairs of speakers sounded more alike than different. They both adhered closely to the Harman frequency-response target curve, which is to say flattish above my room’s Schroeder frequency (about 350Hz). In the treble, I heard virtually no differences—subjectively, both speakers had very similar high-frequency outputs relative to the rest of the musical spectrum, and, commendably, the Focal tweeters sounded just as refined—delicate and airy—as the Revel beryllium tweeters. For example, when listening to “Fast Car,” the level of extension, detail, and nimbleness I heard on the hard-left and hard-right cymbal strikes were the same with both sets of speakers, so I couldn’t even declare a “winner,” at least with that song.

But I did find that the Focals exhibited a touch more vocal sibilance than the Revels on certain tracks. For example, on Norah Jones’s “Turn Me On,” from Come Away with Me (24/192 FLAC, Blue Note Records/Qobuz), Jones’s S sounds were slightly too pronounced at high volume levels through the Focals, whereas the Revels got it just right. That said, the difference was minor. This observation was corroborated by my in-room measurements, which show that the two speakers track very closely from 200Hz to 6kHz, but beyond this point the Revels gently dip while the Focals gently rise, with a 1.5–2dB difference in the 6–8kHz range, where vocal sibilance is most easily heard.

For the midrange presentation, I preferred the far-more-affordable K2 906 standmounts. The French speakers exhibited a hair more presence, so vocals jumped further out from the mix than they did with the Revels—all the while sounding smoother, rounder, and more full-bodied. For me, this is the Focal calling card—a lively and present midrange, coupled with buttery smoothness. For example, when I listened to “Turn Me On” through the K2 906s, I liked how Jones sounded more up front and in the room than she did through the Revels. When she leaned in hard on the mike, her vocal inflections—even when reproduced at a high volume level—sounded smoother and were easier to listen to through the Focals.

When comparing male vocals, Colin James’s singing voice on “National Steel” sounded fuller, rounder, and meatier through the Focals. In terms of transparency, however, the Revels, at almost twice the price, did just edge out the Focals. For example, when I focused on the guitar plucks right of center at the beginning of the track, the attacks and, most noticeably, the decays sounded freer and more disconnected from the cabinets with the Revels.

In terms of soundstage size and specificity, as well as aural image focus and delineation, I’d call it a near tie between both pairs of speakers—both were superb performers in these categories. The image focus was occasionally a bit tighter through the Revels compared with the Focals; perhaps this was due to the denser M126Be cabinet, which might also account for the Revels’ superior transparency. But again, these were very small differences.

The difference in the bass, however, was more obvious. The Revels definitely offered more bass output than the Focals, providing the music with more punch and authority. For example, both the kick drum and bass guitar that underpin the fast pace of Blues Traveler’s “Run-Around” had more weight and authority through the Revels. My in-room measurements corroborated these observations: despite having nearly identical bass extension, the Revels pumped out an extra 4dB at 50Hz compared to the Focals, which likely accounts for the increased weight and authority I heard.

Conclusion

Focal has released yet another winner with the Aria K2 906 loudspeaker. Extremely well built and attractive with an understated elegance, these standmounts, finished in exclusive high-gloss Ash Grey, would fit into just about any décor. In terms of sound, there really wasn’t much to complain about. The midrange was glorious, open, and transparent. There was also attention-grabbing detail, delineation, and presence through the midband, which at the same time sounded buttery smooth. The high frequencies were well balanced—not too hot or too cold, and also very refined. These French speakers acquitted themselves admirably against the Revel M126Be standmounts—reference-caliber two-ways costing almost twice as much as the K2 906 standmounts. They gave up a hair of transparency, but gained the upper hand in midband richness and smoothness. My only complaint with the Focals was the overall bass output, which I found to be a bit on the light side. Bass speed, punch, and detail were top notch, however. Incidentally, I consider the Revels to be adequate, but not exemplary, in terms of bass output for a two-way standmount design in my room.

But let’s face it, bass performance is not only to do with the speakers, but also the room they’re used in, so any prospective buyer may experience more or less bass depending on room size and proximity to walls. With that in mind, and given all that a pair of Focal Aria K2 906s offer, visually and sonically—at just $2398 per pair—I can’t help but enthusiastically recommend these wonderful French loudspeakers.

. . . Diego Estan
diego@soundstage.com

Associated Equipment

• Speakers: Revel M126Be, Focal Sopra No1.
• Subwoofers: SVS SB-4000 (2).
• Power amplifier: McIntosh Laboratory MC302.
• Crossover: Marchand Electronics XM446XLR-A custom balanced line-level 120Hz high pass filter (between preamp and amp).
• Preamplifier-DAC: McIntosh Laboratory C47.
• Room correction EQ: miniDSP DDRC-22D with Dirac Live 3.0 (between digital sources and DAC).
• Digital sources: Rotel RCD 991 CD player, Bluesound Node 2i streamer, Windows 10 laptop running Roon.
• Analog sources: Pro-Ject Debut Carbon Esprit with Ortofon 2M Red cartridge.
• Speaker cables: 12AWG oxygen-free copper, terminated with locking banana plugs.
• Analog interconnects: AmazonBasics RCA, Monoprice Premier balanced XLR.
• Digital interconnects: AmazonBasics Optical TosLink and coaxial RCA cables.

Focal Aria K2 906 Loudspeakers
Price: $2398 per pair.
Warranty: Five years, parts and labor.

Focal Naim America
313 Rue Marion
Repentigny, Quebec J5Z 4W8
Canada
Phone: (800) 663-9352

Website: www.focal.com