Living Large: Wilson Audio Alexx and Thor's Hammer

by Roy Gregory | August 24, 2017

can hear the cries of outrage -- probably mingled with disbelief -- even before these words go live. Given a speaker as big (not to mention as pricey) as Wilson Audio’s Alexx ($109,000 per pair), why would you need to add subwoofers? Indeed, for most of us, the question doesn’t just teeter on the brink of incredulity, it seems, in a very real sense, largely irrelevant. After all, it’s a lucky few who can both afford and accommodate a speaker like the Alexx; even fewer can contemplate the added cost and real estate necessary to add an extra amplifier and subwoofer. But then, as stunningly capable and impressive as this system has proved to be, that’s not really the point of the piece. Those with Alexx can take note; for those without, the proposition is altogether more general in nature -- not so much Why would you? as Just how much can subs add to a system, even one with speakers like the Alexx? The answer is, an astonishing amount.

I wrote at length about the Sasha W/P 2/WATCH Dog/VTL S-400 II combination, a system of quite extraordinary potency, the addition of the subwoofers elevating the already impressive Sasha 2 to a whole new level of musical articulation, communication and authority. The subsequent arrival of the Alexx raised an interesting question: would it be capable of holding its own against the junior tyro, a grand tourer faced with the upstart insouciance of a pumped-up hot hatch? Well, neither Wilson nor I needed to worry. The Alexx brought a microdynamic ease and insight, an expressive range and subtlety, a natural dimensionality and perspective that quite outstripped the rude enthusiasm of the Sasha-based setup. But as impressed as I was with the Alexx as a standalone solution, it too raised its own question: just what would adding a pair of WATCH Dogs ($9800 each) bring to this party?

On the face of it, not too much. Indeed, there were those at Wilson who were skeptical as to the potential benefits, but after my Sasha 2 experience, I was itching to wheel in the WATCH Dogs and let them loose. You should never underestimate the power of real bandwidth, or just how much acoustic power it takes to deliver it. Although on paper, the subs share similar driver dimensions and quoted bandwidth to the woofers in the Alexx, simply doubling up the swept area (not to mention dedicating a second amplifier to low-frequency duties) should make an appreciable difference -- at least, that’s how my reasoning went, and was it ever right. Considering that the WATCH Dogs do little (if anything) to actually extend the low-end reach of the Alexx, their impact on the musical performance of the system was little short of remarkable. Rather than reaching down (as they had so successfully when used with the Sasha 2), here they reached out and back, opening out the soundstage and increasing the acoustic space.

But what was really important was not that they made that space bigger, but that they made it more coherent -- not just more space, but one space. Individual images were more dimensional, more precisely scaled, the spaces between them more defined and transparent -- which all adds to the ability of the system and the performance to convince. But the impression of a single, contiguous space was what really made the difference, a new sense of spatial coherence that was mirrored in the temporal domain. What was happening, where and when became far more apparent. Phrasing and ensemble relationships, rhythmic expression and note-to-note spacing all became more natural, communicated with an unforced ease that brought a grace, poise and finesse to the playing and power to the performance. By creating a firmer and more substantial foundation for the music, one with greater control, definition and headroom, the subs were unlocking the expressive range of the system, anchoring the temporal cues, opening out the midrange and bringing air and space to the acoustic.

In musical terms, these were no small changes. One couple that visited owned Alexias and were considering Alexx as an upgrade. Hearing the Alexx with and without the WATCH Dogs left a single clear conclusion. Before even thinking of Alexx, the next step should be adding subs to their existing speakers. As impressive as the Alexx certainly is, that’s how big a difference simply reinforcing its existing extension can make to the musical experience. All of which left me wondering, what happens if you add power and extension?

Well, be careful what you wish for. The WATCH Dogs are substantial beasts, squat and compact at around 27" on a side (slightly narrower from the front) and 283 pounds each. They pale into lapdog-like insignificance compared to the Thor’s Hammers ($24,000 each). If you thought a pair of WATCH Dogs constituted a perhaps illogical extreme, wait until you experience their bigger brothers. Now, I’ll admit to having a bit of a problem with the most un-Wilson-like name of this product, a name that seems to have more to do with the sort of bluster and excess more often associated with monster A/V rigs than serious two-channel audio systems -- but that was before I met the product in person.

The Hammers stand all but five feet tall. Each sports a pair of 15", dual-spider drive units (as compared to the Dog's single 12" woofer), weighs in on the wrong side of an NFL nose tackle and is nowhere near as mobile -- 412 pounds of dead weight to be precise. A pair of Hammers arriving on your doorstep is no laughing matter, believe me. Thankfully, Wilson’s long experience with similarly outrageous weights and dimensions means that the big subs are considerably easier to handle and position than might be the case. They wheel out of their shipping crates, and the low-profile jack that comes with every Wilson dealer makes installing the spikes once you’ve completed initial positioning, if not a piece of cake, then at least an entirely practical proposition. As always with something this big and this heavy, an extra pair of hands makes life considerably easier.

However, at some point the real fun starts -- and that point is about now. Having a dedicated listening/reviewing room, I made sure that the speakers I’d be working with stood on polished wood flooring, making it simple to effect small, incremental adjustments. Even so, with the Hammers standing on large-diameter footers, it took considerable effort to shift their enormous bulk. How on earth you’d manage on a carpet is entirely beyond me, bearing in mind that there’s a significant difference in height between the wheels and the spikes with the "diode" assemblies into which they screw. In some ways, that height differential is both the bad news and the good. Initial positioning on the wheels is just that -- initial, for which read "approximate." But once the Hammers are spiked, using the spikes to adjust height from the floor and rake angle becomes the final step in fine-tuning the woofers.

Which brings me to the whole issue of placement. With the WATCH Dogs, I positioned them behind the Sasha 2s -- or Alexxes -- and close to (but not hard against) the wall, gaining maximum benefit from the boundary reinforcement. With the Hammers, that acoustic gain wasn’t necessary, allowing me to move them forward to a position immediately behind and just outside the Alexxes, a closer coupled arrangement that allowed for better integration but also more exacting placement.

What quickly became apparent was that lateral positioning/spacing of both the woofers and the main speakers was critical. Having played with the subs at some length, it emerged that proper integration was going to require some adjustment of the main speaker siting. Once you start to think about this, it actually makes sense. In setting up the Alexx as a standalone system, you are balancing its bottom-end output against the room nodes, trading off weight, articulation and extension. But with the Hammers singing along, any added weight in the Alexxes’ nether regions becomes an embarrassment, generating an overlap and muddiness that slows proceedings quite noticeably.

Nudging the Alexxes together by around 10mm cleaned things up nicely. Now it became a case of moving the subs forward to achieve optimum weight and linearity, sideways for integration and then working with the height and rake angle to get them really dialed in. Sounds simple? As a process it took weeks, first with the Naim Statement amps, then repeated for the VTL Siegfried IIs/S-400 II, with their very different bottom-end balance and voicing. Ultimately, the VTLs mandated a forward shift of the woofers by around 3mm and raising them by a turn and a half on the spikes, maintaining the same lateral distance and slight rearward rake. That might not seem like a lot but believe me, in the context of the context of this system and its speaker positioning, it’s a huge step, both sonically and musically. It underlines just how much care and attention needs to be lavished on any full-range system, but on subwoofers in particular -- at least if you are going to realize their full potential.

Subwoofers: the conditions for success

For many years, subwoofers were an exotic rarity, as often as not built into the structure of an enthusiast’s room. It wasn’t until the advent of A/V and surround systems that they became plentiful and affordable. The problem is that the requirements of an A/V system (which largely center on quantity) are well removed from those of a two-channel setup, whose demands are entirely based on quality and integration. After all, who actually knows what a train wreck sounds like -- but the ear instantly identifies any nonlinearity, discontinuity or timing error in the rhythmic underpinnings of music.

Over time, I’ve developed a set of guidelines for the successful use of subwoofers in two-channel setups that together constitute an ideal. Some subs might get away with flouting one dictate, but follow them all and you’ve got a much, much better chance of success.

1. The crossover needs to approach the same standard of build and quality as the preamp driving it and be used in parallel to the main speaker feed.

2. The worst possible place for the fragile electronics controlling and driving the sub is within the cabinet itself.

3. Two subs is always better than one -- although one can be a useful stepping stone.

It should be immediately obvious that almost all the subs on the market break rules number one and two. What is less obvious is that they break them in a number of different ways. For starters, using DSP crossovers introduces insoluble latency issues that all the room correction in the world won’t fix. Likewise, using a separate crossover opens up the opportunity of using identical amplification to drive both the subs and the main speakers -- something that dramatically improves system integration. Trying to integrate two distinct outputs, one driven by an SET amp, the other by some muscle-bound class-AB (or worse class-D) module, bought off the shelf because "It only has to drive the bass" is beyond possibility -- at least if the quality of the end result is a serious consideration. The one thing that hearing a set of subs working properly should tell you is that there is no such thing as "only" the bass. It is the very foundation of music and you undermine it at your peril. Mess up the bass and it will mess up everything else. In fact, no bass is better than bad bass, which helps explain why subs get such a bad press in the two-channel world.

But done properly, with a high-quality, separate crossover, serious amplification and the requisite care and attention paid to positioning and setup, they are capable of making a musical contribution that isn’t just fundamental, it can be spectacular -- often in the ways you least expect. Subwoofers are all about bass, but in musical terms they are about organization, timing, articulation and expression: all the things that bridge that gap to the presence and immediacy of live performance. Just don’t go thinking that some $2000, A/V-orientated cube is the be-all and end-all.

-Roy Gregory

But what potential. As impressive as the Alexx is on its own, add the Hammers to the mix and you are in a completely different place, musically and experientially. Many people came to hear this system. To understand just how rare it is to find a rig this big and this extravagant you need to appreciate that even the great and the good at Naim Audio had never heard a Statement preamp driving four Statement power amps in a single setup. Besides which, who doesn’t want to hear a pair of subs that are almost big enough to sleep in?

That very fact raises its own presentational dilemma: what’s the first thing you play? In my case, the disc I found myself reaching for was almost invariably Ninna Nanna [Alia Vox AV9826], Montserrat Figueras singing a collection of lullabies from across the ages, the chosen track "Mareta, mareta no’m faces plorar," a duet with her daughter, Arianna Savall. With minimal accompaniment from baroque flute, guitar, viola de gamba ad finger bells, the fragile balance of the voices haa a breathtaking delicacy and beauty, a soaring purity yet remarkable presence. It’s a gorgeous recording and performance on almost any system, including, of course, the Alexx.

But add the Hammers and, from the first scatter of tiny chimes, the natural presence, sense of space around the performers, and their relative locations become unquestionably clear, almost explicit, both through the separation of their contributions, but also the musical dialogue between them. This dimensionality and natural perspective are perhaps the most obvious artifact of serious bass extension, but there’s far more to the contribution of decent subs than a bit of air and space. The sense of being in the same room or space as the performers is quite uncanny, almost as if the acoustic reaches forward and encloses you in the same volume of energized air. The natural size of the instruments, the obvious distinction between their bodies and strings, the way each different instrument is held by its seated player and the height differences that result between them and also the voices of the standing singers add an air of living, breathing humanity to the performance, all of which contributes to the illusion of real people and a real performance there in your room.

Better still, the clarity the subs bring to the event means that who is doing what, as well as exactly where and when they’re doing it, is effortlessly apparent -- and thus, so too is the why, making for an engaging and communicative listening experience, one that invites you to forget the system and get lost in the music. So, although the dimensionality of the soundstage and the solidity of the images that populate it are themselves impressive (and definitely nice to have), it’s what that ability implies in the temporal and musical realms that really matters. The natural grace, relaxed, unforced sense of rhythm and ensemble, the feeling of a real band, really playing together: that’s what the Alexx/Hammer combination serves up when fed a recording of this quality -- and it’s what stopped listeners in their tracks, especially those expecting larger-than-life dynamics and thunderous bass. Yes, subs will add scale and weight, but what they really do is make sense of the music.

Bandwidth and dimensionality, especially the sense of an overarching acoustic, might be indivisible, but as I’ve already suggested, it’s easy to get distracted by this most immediately obvious of virtues and miss its real implications, the more fundamental musical benefits of really wide bandwidth. So, why not remove soundstaging as an issue? It’s an instructive exercise. Warner Classics recently released a CD boxed set of David Oistrakh’s complete EMI recordings [Warner 50999 2 14712 2 3], a superb collection that contains masterful performances, many dating from the early 1950s -- and hence in mono. One brilliant example is the Sibelius violin concerto, recorded in 1954 with the Stockholm Festival Orchestra under the baton of Sixten Ehrling. Play this disc on the Alexx and its mono character is both familiar and disappointing, the over-large solo instrument pushed forward, loud in front of a diminished orchestra, a single, small collective behind the violin. The balance is skewed toward the solo instrument and the result is that Oistrakh’s playing, while undoubtedly powerful, is also uncharacteristically clumsy and angular.

Restoring the subs to the system transforms both the presentation and the musical experience. Right from the muted opening bars, there’s a tingling sense of tension in the violins, a sense of the atmosphere in the recording, a scale and weight that are just there, waiting to explode. Oistrakh’s instrument steps back, both in terms of location and scale, occupying the same space as the orchestra. Even if you can’t hear that space in terms of its dimensions, you can certainly hear its effect in terms of the balance and tonality of the instruments. Oistrakh’s playing soars, that clumsy, awkward feeling replaced by the poise and control, the fluid grace and phrasing that you expect from his bow -- and as the first movement builds, the weight and richness of the orchestra emerges to underpin the soloist.

What emerges is a deeply affecting performance of this most testing and difficult of concertos -- yet without the subs it’s a disc I would only ever have returned to for academic reasons. By restoring the scale and timing, the balance between orchestra and soloist as well as the musical relationship between them, the subs allow access to what is a brilliant reading -- and a deftly judged recording -- access that is denied to lesser systems.

Okay, so I’ve teased you long enough. Time to roll out the big guns -- in some cases, almost literally. Having roundly condemned the excesses of A/V-orientated subwoofers, I find it’s somewhat ironic to reach for movie soundtracks to show off the dynamic prowess of the Hammers, the sheer musical intensity they allow, but these days the movies are one the few employers who can afford really large-scale orchestration (or who are equipped to really reproduce it) be that the soundtrack for Glory, Gladiator or the various Batman movies. You want power and a recording that demands massive headroom? Look no further than the musical accompaniment to moving images, big on atmosphere, bigger yet on dynamic swings.

Hans Zimmer is pretty much king of the current soundtrack crowd, but when I’m looking for big, I’m also looking for subtle, and I find it in his slightly earlier work, notably the score for Terrence Malick’s Thin Red Line [RCA Victor 09026-63382-2]. One of my formative audio experiences was hearing "Journey To The Line" at Sea Cliff on the giant Scaena system, a setup with subs that literally shook the room -- in fact, the whole house. The concrete construction of my room stands the impact of the giant drum beats much better, from the initial impact of the mallet and texture of the skin, to the volume of the drum itself and the note rolling through the room. But as impressively physical as that experience is, what is really startling about the Alexx/Hammer rig is the way it allows me to appreciate the subtleties of the track, the way it builds so insistently and inevitably toward that shattering crescendo. It’s not just the ticking of the clocks, marking time -- it’s the fact that for the first time I can hear them arrayed across the stage in a single, uninterrupted line, a line that stays there, ticking away right through the track, as layer on layer of instrumentation builds. Likewise, the shimmering cascades of the track "Light" take on an almost aching beauty and when that huge drum reappears in isolation (in the track "Air"), the way the beats pulse and their energy and tone expands sounds incredibly natural and real, perfectly capturing the sense of weight, scale and the distance to he instrument.

Take this ability to reproduce the sense of space and scale in a recording, together with the pattern and organization of the music within it and the sort of dynamic headroom that comes with four channels of genuinely powerful amplification (a point I’ll get to a little later), and you have a system that excels on live recordings, large or small. Polskie Radio’s fantastic SACD of Gorecki conducting his own 3rd Symphony is a perfect example: the split instrumental sections that layer the complex melodies, building, always building, on the slowly evolving depth of the bass lines; the gradual development of the movements that maintains the musical pulse; the shattering intensity of the soprano parts, sung by Zofia Kilanowicz. The bandwidth that comes with the big subs doesn’t just reproduce the layering in the music or the strange, stacked-up arrangement of the orchestra (mandated by the venue, the Holy Cross Church in Zakopane), or the height and space in the towering acoustic -- although it does all those things without apparent effort. It’s real contribution comes in maintaining the tempo and forward motion of this slow, almost stately piece, building a feeling of gravity and power where so many systems allow it to become turgid. This measured pace is crucial to a symphony of three slow movements, subtitled the "Symphony of Sorrowful Songs." The pain, horror and anguish that underpin this music have never been so apparent, or so emotionally affecting.

So far, most of the examples I’ve cited have been CD or SACD based, but don’t go getting the idea that the use of super subs debars vinyl replay. Okay, so I didn’t dig out the LP12, but the Kuzma Stabi M and a variety of other ‘tables saw continual use throughout the time I’ve been assembling this article. In fact, despite the relatively limited bandwidth of the source (at least when compared to the low-frequency linearity of digital media) and just like smaller, more intimate recordings, LP proved spectacularly successful. As I’ve probably said before, if you’ve ever wondered just how Kurt Cobain captured the hearts and minds of a generation, you need only listen to Nirvana's Unplugged In New York [DGC/Original Recordings Group ORG 034]. From the beautifully tactile and tuneful progression of Krist Novoselic’s bass on "Come As You Are" to Cobain’s heartfelt vocals and sparse, slashing guitar riffs to the upbeat "On A Plain" or the downbeat "Something In The Way," never has this music made so much sense, has its deeply emotional root been so obviously or powerfully revealed. Run the gamut of Elvis Costello’s bitter wit or Joe Jackson’s subtle, sardonic, self-deprecation and over and again, the power and purpose that underpins great pop is laid bare.

More than space, weight or scale, what real bandwidth brings to music is the sense and purpose behind the performance. If music is a pattern defined in pitch and time, then the further you can extend that pattern, the more sense it makes, an academic proposition that is thrown into stark focus by the experience of the Thor’s Hammers and what their sub-30Hz contribution adds to the already impressively wide-bandwidth Alexx.

But to really appreciate the potential lurking in these massive boxes, you need the amps to energize them. The Naim Statements were massively impressive partners in every sense, from their striking Rockefeller-esque looks, to their utter stability, awesome grip and unflappable headroom. The shape, texture, attack and placement they brought to the system’s bottom end -- and the seamless way in which they integrated and fastened it to the rest of the musical range underlined once again that these amps don’t just mark Naim’s belated arrival at solid-state audio’s high-end top-table, that they’ve crashed in straight at the head of affairs, with a performance that finally (and emphatically) backs up the rhetoric.

The use of four, identical monoblocks (as enabled by the Statements) is of course the ideal, aided considerably by geographical proximity -- the Naim factory was a mere 12 miles up the road. Even so, it was a feat of considerable logistical juggling to get four power amps in one place, not least because as soon as Naim builds a set, there’s an order waiting. Nor does that situation improve with alternative amps. Wanting to run both solid-state and tube electronics, you quickly run into similar issues, and I was lucky enough to secure a pair of VTL Siegfried IIs to partner my own S-400 II, a combination that not only offers continuity from the Sasha 2/WATCH Dog/S-400 II setup (the S-400 II being in effect, a stereo Siegfried II) but also offers the opportunity to look at which amps work best in which role, as well as to answer that other logistically impaired proposition, just how does the S-400 II compare to it bigger brother.

To cut a long story short -- and gloss over endless switching of cables, along with the inevitable missteps -- the preferred configuration proved to be using the Siegfried IIs on the subs, the S-400 II on the Alexxes. It wasn’t just a case of greater bottom-end control and transparency. On a disc like the Gorecki, with its layers of deep, almost ponderous bowed bass, the Siegfried IIs delivered better focus, texture and pitch definition, separating the different ranks of instruments more convincingly, as well as tying their disparate threads more solidly together. But almost more important was the immediacy and quickness that came to the midband, reflected not just in the percussive explosions of the opening applause, but in the increased air and blackness of the acoustic and the way it reached forward to include you in the audience. Now, whether that’s down to the quality of the Siegfried IIs underpinning the rest of the range or a combination of the Siegfried IIs’ control and the S-400 II’s midrange articulation and liveliness, only time and closer comparison of the two amps will tell, but one thing is certainly clear: when it comes to low frequencies, you simply can’t afford to skimp on power and headroom.

How do the two sets of amps compare, tube to solid state? The Naims rest their performance on control, definition and absolute stability. The VTLs deliver a more defined and more palpable sense of acoustic and instrumental presence. Either is a perfectly viable option, with final choice coming down to personal preference and musical taste. I can see the classical devotee loving the sense of life and presence that comes from the tubes, the jazz aficionado loving his immediacy and harmonic sophistication, while the rock or pop listener, the lover of scale and level and complexity, will adore the effortless ability of the Statements to sort out the most complex of mixes. But beyond the obvious and well-worn differences in midband presentation, the VTLs hold their own in this company on the basis of their power and bottom-end grip, both exceptional for tube designs -- and salutary in the context of this wider investigation.

Spend time with a set of well-engineered and well-setup subs and you quickly realize that there really is no substitute for bandwidth, but for that bandwidth to be effective it needs to match the quality of the midband in terms of subtlety and transparency, headroom and dynamic resolution. The entire musical range rests on the bass: slow or slur that bass and you place a drag on the midrange and everything that rests on that too. Most systems survive by clipping bass notes or curtailing extension, limiting the demands the bottom-end places on the rest of the system and the room, but that surrenders any serious intent to approach the audio ideal of reproducing the sense and sensibility of the original recording -- whether that’s an orchestral extravaganza or a girl and guitar.

If you are going to do bass you need to do it properly and that is inevitably difficult and costly. Putting the bass units in a separate box (or boxes) gives you advantages in terms of optimizing position, both for the sub(s) and the main enclosures, as well as minimizing intermodulation distortion. But it doesn’t mean that you can skimp on the construction of the bass cabinet, or the amplifier driving it. Put the electronics in the same box as the bass drivers and you’ll lose more in terms of microphony than you gained in separating the cabinets in the first place.

So, no, there are no easy -- and certainly no cheap -- answers to delivering serious bottom-end bandwidth. DSP isn’t the magic-bullet cure that its advocates claim. Instead it’s down to brute-force quantities of tried-and-trusted technology. But bass extension is becoming an increasingly hot topic, with speakers like Wilson’s Sabrina and the Vienna Acoustics Liszt demonstrating just how important an effective sense of scale is to a musically rewarding system, high-res recordings placing increasing demands on the system’s acoustic and dimensional capabilities and current pop producers using more low-frequency weight than ever before.

At their price, plus the cost of the crossover and a driving amplifier, the Thor’s Hammer can hardly be described as cost-effective -- until you’ve lived with it. Then it starts to make a horribly compelling sort of sense, especially in the context of a system that already contains amplification and speakers that have breached the five-figure price barrier. I’m fortunate enough to breathe a heady and rarefied audio oxygen, one in which frighteningly expensive components come and go on an almost daily basis. But since living with first the WATCH Dogs and now the Hammers, there really is no going back. Bandwidth, real bandwidth, has an addictive quality, an ability to satisfy and convince that underpins the very promise and proposition of high-end audio.

The Alexx is a fabulous speaker, but its coherence and articulation, presence and tonal sophistication, its resolution and dynamic capabilities are taken to an even greater level when you add serious subwoofers to the mix. The challenge for Wilson and the industry as a whole is to make that reality a possibility at more affordable price points and in less extravagant systems. Then we’d really be delivering the musical goods.

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