Wilson Audio Specialties Alexia, Stereophile 12/2013

Stereophile 12/2013

John Atkinson 

Wilson Audio Specialties Alexia loudspeaker

With the help of 20:20 hindsight, it looks as if I made a decision when I joined Stereophile: to review a loudspeaker from Wilson Audio Specialties every 11 years. In June 1991, I reported on Wilson's WATT 3/Puppy 2 combination, which cost $12,740/pair in an automotive gloss-paint finish. This was followed in July 2002 by my review of the Wilson Sophia ($11,700/pair). And now, in December 2013, I am writing about the Wilson Alexia, which costs a not-inconsiderable $48,500/pair.
I first heard the Alexia at the 2012 Rocky Mountain Audio Fest, but didn't decide that I needed to get a pair into my listening room until the following January, when, at the 2013 Consumer Electronics Show, I heard a pair of them driven by Dan D'Agostino amplifiers and a dCS Vivaldi digital source, hooked up with Transparent cables. As I wrote in my online report from CES 2013, when I heard the hi-rez master file of Cantus singing Eric Whitacre's Lux Aurumque, "not only was the relationship between the sounds of the singers and musicians and the surrounding ambience of the recording venue breathtakingly real, so was the relationship between the musicians and the music. I have played Lux Aurumque on dozens of systems—never have I heard it sound so real, so musically involving." (footnote 1)

The Alexia
The floorstanding Alexia bears a strong family resemblance to the two earlier Wilson speakers I reviewed. Its truncated pyramidal profile resembles the Sophia's, while, like the WATT/Puppy, it comprises separate enclosures: the lower, rectangular one holds the two woofers, and the upper, pyramidal one the midrange unit and tweeter on its sloped-back front. And the Alexia is finished in high-gloss automotive paint. There the resemblance ends. The Alexia is larger than either of the earlier speakers. The latest (and best-sounding) iteration of the WATT/Puppy, the W/P Sasha, reviewed by Art Dudley in July 2010, stands 44" high and weighs 197 lbs. At almost 54" tall, the Alexia is a head taller than the Sasha and weighs a backbreaking 256 lbs. But the newer speaker wears its bulk well, and its footprint in the listening room is not significantly greater than those of the smaller speakers.

The more significant difference concerns the drive-units. Like Wilson's various MAXX and Alexandria models, the Alexia's two woofers are of different sizes. An 8" woofer is mounted above a 10", both loaded with a large, 3"-diameter, aluminum-lined port on the cabinet rear. The idea behind using two woofers of different sizes is that the radiation pattern of the smaller one at the top of its passband better matches that of the midrange unit at the bottom of its passband. Whereas the XLF's woofer cones are made of Focal's proprietary W sandwich material and the Sasha's twin 8" cones are of polymer, the Alexia's bass drivers have paper cones.

The Alexia's 7" midrange driver, mounted in its own enclosure, is the same as that used in the XLF; it features a composite pulp/carbon-fiber cone, with a substantial half-roll rubber surround to confer greater dynamic range at the bottom of its passband. The midrange unit is resistively loaded by two foam-lined vertical slots on the rear panel, and the enclosure can be moved back and forth and have its tilt adjusted with spikes of various size that couple its rear to a stepped metal plate on the top of the woofer module. The Alexia's tweeter is a variation of the sophisticated silk-dome model Wilson used in the Alexandria XLF. This, too, is mounted in its own enclosure, which engages with both the top of the midrange enclosure and the underside of the black-anodized aluminum "bridge" that covers the module via spikes that sit in grooves machined into metal plates. The tweeter module can also be moved forward and back, and tilted, with respect to the midrange enclosure on which it sits. Wilson calls this ability to fine-tune the upper-frequency drivers Aspherical Group Delay; I refer you to Michael Fremer's explanation. Electrical connection is via a single pair of brass binding posts mounted the rear of the woofer enclosure and standing proud of the cabinet. Two pairs of heavy-gauge cables emerge from the top of the woofer enclosure, and connect to two pairs of binding posts on the rear of the midrange enclosure: one pair each for the midrange and tweeter. All four of the Alexia's drive-units are connected with series power resistors in their feeds from the crossover, which is inside the woofer enclosure. The resistors for the upper-frequency units are accessible behind a metal plate on the top rear of the woofer enclosure. These are mounted on a heatsink and held in place by Allen-head bolts. Replacement is easy, and different values can be substituted to adjust the levels of the tweeter and midrange. Barrel resistors adjust the woofer level and damping; these are not intended to be changed by the buyer.

In common with the W/P Sasha and Alexandria XLF, the Alexia's enclosures are far removed from the usual rectangular monkey coffin. A subtle wave motif is machined into the woofer enclosure's side panels, and a pair of vertical walls flank the midrange module. The midrange enclosure is fundamentally a truncated pyramid, but with shoulders machined into the side panels and enclosing sidewalls rising either side of the small tweeter module, to support the metal bridge mentioned above. The walls of the woofer enclosure are built entirely of Wilson's proprietary X-Material, a mineral-loaded phenolic compound that is both extremely stiff and difficult to machine. Laser interferometry was used to optimize wall thickness and the placement of internal braces. Cloth-over-frame grilles are provided for each of the three modules; these have pins that plug into matching sockets in the front baffles. The Alexia was designed by Dave Wilson and Vern Credille, Wilson's lead acoustic and electrical engineer. It is gorgeous to look at, but what matters most to audiophiles is how it sounds.

Setup
Wilson Audio is known for its attention to detail, even when that detail might seem unnecessary. For example, the manual states, "Place the ODD numbered modules in the LEFT channel section and the EVEN in the RIGHT channel position." Even the packaging is superbly thought out, and complete sets of tools and accessories are provided. Perhaps as should be expected at this price level, Wilson works hard to maximize the purchaser's pride of ownership. The head units are both contained in one crate; each woofer cabinet rolls out of its individual crate on sturdy wheels, which allow the speakers' positions in the room to be easily fine-tuned despite their size and weight.

When you buy a pair of Wilson Audio Specialties loudspeakers, the retailer will install them in your home and perform that fine-tuning. In my case, Wilson's Peter McGrath did the deed. Having adjusted the position and tilt of the tweeter and midrange modules for the height of my ears in my listening chair and their distance from the speakers—the exact settings are detailed in the manual's "Propagation Delay Correction" table—he rolled each speaker back and forth, and from side to side, until he was confident that they were close to their optimal positions. McGrath then placed two strips of masking tape at 90° to one another, each marked with a ½"-spaced grid. Listening carefully to each speaker in turn, he moved the enclosure in ½" steps in both planes and adjusted the toe-in until each Alexia sounded its best. (The grilles were left off.) He then replaced the wheels with the spiked feet and declared himself satisfied.

McGrath had fine-tuned this setup using a single track: "So Do I," from singer-songwriter Christy Moore's This Is the Day (CD, Sony 5032552). I asked him what was so helpful about this recording. "This track features two acoustic guitars, double bass, and voice. There's a little bit of reverb on the voice, enough elements to make it sufficiently complex, but not overwhelmingly so," he explained. "The voice has been recorded without microphone proximity effect, so if you hear what sounds like proximity effect, it's actually due to a room mode."

Listening
When Peter McGrath left, I began my own listening. Pink noise sounded smooth and uncolored when I was sitting in my chair on the exact listening axis set by McGrath, using the position adjustments for the tweeter and midrange modules and the precise amount of toe-in he'd settled on. However, if I moved slightly above or below that position, a narrow band of brightness became apparent.

The 1/3-octave bass-warble tones on Editor's Choice (CD, Stereophile STPH016-2) sounded powerful down to the 25Hz band, with the 40Hz warble slightly down in level, the 32Hz warble exaggerated by the lowest mode in my room, and with the 20Hz warble still faintly audible. The half-step–spaced tonebursts on Editor's Choice spoke cleanly and evenly throughout the bass and midrange regions. When I listened to the woofer cabinet with a stethoscope, all surfaces were impressively inert. The midrange enclosure was also well damped, though the rear panel above the terminals was slightly lively around 525Hz, and the sidewalls had a low-level mode between 300 and 400Hz.
Enough of test tones. Fittingly, the first musical work I played through the Alexias was Beethoven's Violin Sonata 10 in G, Op.96 No.1, performed by violinist David Abel and pianist Julie Steinberg (24-bit/192kHz needle drop from LP, Wilson Audio W-8315). David Wilson, founder and president of Wilson Audio, had recorded this LP 30 years ago using a modified ReVox A77 tape deck with a pair of Schoeps omnidirectional microphones and a modified Audio Research preamplifier. In a February 1984 review, J. Gordon Holt described this recording as having "sound so completely and disarmingly natural that after 30 seconds you're unaware it's reproduced." Through the Alexias, the balance of the instruments was intimate yet unforced. They were reproduced with faithful tone colors—I heard no colorations—and the imaging was such that the musicians seemed to be in my room.

Next up was bluegrass virtuoso Chris Thile's performance of his transcriptions for mandolin of J.S. Bach's Sonatas and Partitas for Solo Violin. John Marks had sent me a YouTube link to Thile performing the Preludio from the Partita 3 in E; even with YouTube sound quality, Thile's musicianship was so convincing that I purchased the complete set (24/44.1 ALAC files, Nonesuch/HDtracks). I was right to do so. Thile gets the essence of these very violinistic works right. Yes, the mandolin's four courses of doubled strings are tuned the same as the violin's four strings, but that in itself does not guarantee that the transcriptions will work.

However, Thile's light and shade in his phrasing is so empathetic that he almost convinces the listener that Bach had the mandolin in mind. The image of his instrument hung between and behind the Alexias, uncolored and well defined, with just the occasional plectrum stroke splashing off the walls of the dry recording venue.

Some big speakers sound big all the time. By contrast, the Alexia, though by no means a small speaker, was a chameleon. When the music demanded it, as with the Chris Thile album, the Alexia was a minimonitor. When the music was of larger scale, as with a 1987 recording of Fauré's Requiem with Robert Shaw conducting the Atlanta Symphony and Chorus (CD, Telarc 80135), the Alexias grew to accommodate the recorded sound, but without individual objects within the soundstage becoming exaggerated.

This was one of the strengths of the Alexias: stereo images weren't bloated. With naturally captured recordings, everything was to the right scale. The image of the solo violin in the Sanctus of Fauré's Requiem, for example, was appropriately tiny. Similarly with the solo violin backed by a string choir that introduces the mezzo-soprano aria "Erbarme dich, mein Gott," from John Butt and the Dunedin Consort's performance of Bach's St. Matthew Passion (24/88.2 Studio Master download, Linn CKD 313P): Instrumental images were the right size at all frequencies. The original 1924 acoustic recording of the Paul Whiteman Concert Orchestra performing Rhapsody in Blue, with Gershwin himself on piano (an MP3 transcribed from 78s), was reproduced as a nearly dimensionless sphere of sound midway between the speakers. The piano had good body to its tone, and despite the mono recording, the music was well differentiated from the background shellac noise.

After a few weeks, I began to feel that some recordings were lacking in top-octave air. For example, the jingles of the tambourine in "I Got Plenty o' Nuttin'," from Brian Wilson's Reimagines Gershwin (ALAC files ripped from CD, Walt Disney), a delightful arrangement with bass harmonica echoing the signature of Pet Sounds, were a little suppressed. I asked Wilson Audio for a different set of resistors that would increase the tweeter level a little.

As you can see from the "Measurements" sidebar, the new resistors raised the tweeter's sensitivity by about 1dB. This might not seem a lot, but it turned out to be very audible—not surprising when you consider the tweeter's wide passband. (A speaker I reviewed several years ago had 0.5dB tweeter-level adjustments; the optimal setting turned out to be between two of these steps.) The 1dB boost was a little too much with the Classé CTM-600 monoblocks, but was perfect for the softer-toned Pass Labs XA-60.5 amplifiers. The Alexia's bass needed the Classés' firm control, however—this speaker needs a tight fist on its low frequencies. The bass guitar in the Levon Helm Band's live performance of Dylan's "It Takes a Lot to Laugh, It Takes a Train to Cry," from MerleFest Ramble: MerleFest, NC 4/26/08 (26/96 Apple Lossless file transcoded from FLAC, FestivalLink.net), sounded just too tubby with any of the amplifiers I had to hand, other than the Classés.

But with less overcooked recordings, the Alexia's low frequencies spoke with clarity and authority. The tone of my fretless Carvin bass, played through a PJB Bass Briefcase with an auxiliary Hartke 2x10 cabinet—a sound I know very well—in a live recording I made of George Gershwin's "Summertime," accompanying Bob Reina on Rhodes piano and Mark Flynn on drums, and using a crossed pair of DPA cardioids and my Nagra-D recorder, was as natural as I have heard. And the ambience of the outdoor, poolside venue—including the ringing of someone's cell phone—was almost fetishistic in its resolution of fine detail.

I had played with Bob on another live recording of "Summertime," this time at the Chicago Experience during the 1993 Summer CES. I was playing my Fender Precision through an Ampeg SVT 8x10 cabinet, and Bob was using a Hammond organ stop on his electronic keyboard. Unfortunately, the tessitura of his left-hand register neatly overlapped the bass guitar's, and through most speakers the two bass lines, as they underlie guitarist Frank Doris's killer solo lines, blur into mud. Not through the Alexias.

Piano was well served by the Alexias. My favorite performance of Brahms's Piano Concerto 2 is by Emil Gilels with the Berlin Philharmonic conducted by Eugen Jochum (Apple Lossless files ripped from CD, Deutsche Grammophon). The low notes of the piano's entrance following the lonely horn motif at the start literally growled out of the Alexias. Yes, the orchestral sound on this 1972 recording is a little on the dry side, and the orchestra tends to peer over the shoulders of the solo instrument, but the piano was muscular on the Wilsons.

With the increase in tweeter level, Keith Jarrett's piano on The Köln Concert had a vivid, vibrant sound (24/96 FLAC files, ECM/HDtracks)—perhaps a touch too vibrant. However, the high frequencies of Art Lande's equally closely miked Steinway on his While She Sleeps (SACD, Blue Coast BCRSA 2012a) sounded perfectly in balance with the midrange.

What the Alexias did better than almost any other speaker I've had in my listening room was to preserve differentiations among singers. In close harmony, the characters of individual voices didn't run together, yet ensemble blends were not diluted. This is very much what you hear in real life.

For example, in 2007 I recorded Cantus's While You Are Alive (CD, Cantus CTS-1208), the album of contemporary choral music that included Eric Whitacre's Lux Aurumque, mentioned earlier (footnote 2). That album takes its title from a line in the lyric of A Sound Like This, settings of poems by Kabir (translated by Robert Bly) commissioned by Cantus from Minnesotan composer Edie Hill. Hill wrote the piece with each of the nine singers featured on this recording in mind, specifically tailoring the tessituras and harmonies for their voices. In an aleatoric section in the penultimate movement, each singer enters in turn, singing the same lyric but with a different pitch and timing. Very rapidly, what was originally the pure tone of one singer is transformed into pitchless chaos. The high-resolution file postpones that onset of chaotic sound a little compared with the CD—yet such was the resolving power of the Alexias, especially when driven by the Lamm M1.2 monoblocks, that that breakdown of pitch was postponed even longer.

And in the fourth movement, Thinkers Listen, spoken dialogue is accompanied by hand claps, knee and chest slaps, and stamping feet, all of which, via the Alexias, lit up the acoustic of Goshen College's Sauder Hall like photographic flashes.

Peter McGrath's use of a Christy Moore track to fine-tune the Alexias' positions reminded me that Moore had once played with Irish band Moving Hearts. Though their 1985 instrumental album, The Storm (LP, Tara 1304), doesn't include Moore, it was in heavy rotation in my system in the days before I joined Stereophile. This album mixes traditional Irish melodies and instruments with synthesizer, electric and acoustic guitars, bass guitar, saxophones, bouzouki, and rock drums. The day before the Alexias were to be returned to Wilson, I ripped The Storm to 24/192 AIFF files using the Ayre Acoustics QA-9 A/D converter.

The needle drop demonstrated all of the Alexia's strengths: The speaker's superbly clear low frequencies kept separate the similarly pitched sounds of the bodhran and tom toms, and allowed the bass guitar to remain clearly differentiated in the mix from the kick drum; the clean, uncolored treble allowed Davy Spillane's uilleann pipes to wail convincingly; the unrestrained dynamic range revealed the layering of musical dynamics that Spillane achieves by increasing the complexity of his ornamentation at climaxes as his pipes are doubled by other melody instruments; the speaker's superb clarity allowed the subtle ambience surrounding Spillane's low whistle and Eoghan O'Neill's fretless bass in the final track, "May Morning Dew," to be readily resolved; but most important, as with While You Are Alive, the Wilson speakers allowed the integrity of the music making to shine, unencumbered by artifice.

Summing Up
I have now listened on several occasions to Wilson Audio's Alexandria XLF speakers in Michael Fremer's listening room, as well as in David Wilson's own listening room and at retailers Definitive Audio (Seattle) and Innovative Audio (Manhattan). As impressed as I have been by Wilson's flagship loudspeaker, bear in mind that the XLF costs a mind-blowing $200,000/pair. I am actually more impressed by the Alexia, which, at one-fourth the XLF's price, gets remarkably close to its bigger sibling in terms of musical satisfaction.

Yes, $48,500/pair makes the Alexia still an expensive loudspeaker. But its clarity, its uncolored, full-range balance, its flexibility in setup and optimization, and most of all its sheer musicality, are, if not unrivaled, rare. If I were to retire tomorrow, the Wilson Alexia would be the speaker I would buy to provide the musical accompaniment to that retirement.