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Reviewer: Srajan Ebaen
Source: Zanden Audio Model 2000P/5000S; Ancient Audio Lektor Prime
Preamp/Integrated: ModWright SWL 9.0SE; Music First Audio Passive Magnetic; Bel Canto Design PRe3; Wyetech Labs Jade; Supratek Cabernet Dual; Melody HiFi I2A3; Eastern Electric M520; April Music Aura Note [on review]

Amp: 2 x Audiosector Patek SE; Yamamoto A-08S; FirstWatt F3; Bel Canto e.One S300
Headphone systems: Opera Audio Reference 2.2 Linear, Melody/Onix SP3 with KT77s or FirstWatt F1, AKG K-1000s w. hardwired Stefan AudioArt harness; Raysonic CD128, Yamamoto HA-02, audio-technica W-1000s
Digital recording: Red Wine Audio-modified Olive Symphony

Speakers: Zu Cable Definition Pro in custom lacquer with Rane PEQ55 below 40Hz; Anthony Gallo Acoustics Ref 3.1; Mark & Daniel Ruby with Omni Harmonizer; WLM Diva Monitor, Duo 12 and System Control [on review]
Cables: Crystal Cable Ultra complete wire harness; Zanden Audio proprietary I²S cable, Zu Cable Varial, Gede, Libtech and Ibis; Stealth Audio Cable Indra, MetaCarbon & NanoFiber [on loan]; SilverFi interconnects; Crystal Cable Reference power cords; double cryo'd Acrolink with Furutech UK plug between wall and transformer
Stands: 2 x Grand Prix Audio Monaco Modular 4-tier
Powerline conditioning: 2 x Walker Audio Velocitor S fed from custom AudioSector 1.5KV Plitron step-down transformer with balanced power output option
Sundry accessories: GPA Formula Carbon/Kevlar shelf for transport; GPA Apex footers underneath stand, DAC and amp; Walker Audio Extreme SST on all connections; Walker Audio Vivid CD cleaner; Walker Audio Reference HDLs; Furutech RD-2 CD demagnetizer
Room size: 16' w x 21' d x 9' h in short-wall setup, with openly adjoining 15' x 35' living room

Review Component Retail: €3,600 Duo 12 | €1,090 Bass Control | €1,490 Pre/Passive Control

The Cro Magnon impulse
Buxom ladies with bee stung lips. They're in extreme states of undress. They rub against 1800cc motorcycles. Nautilus-toned buns as polished as the chromed and staggered pipes push up high on pointed heels. Only adolescent males would possibly imagine just how erotic cold metal should seem to the inner thighs of professional models. Flip through any 4x4 mag or chopper rag though and sex and machismo are the holy twinity. Go forth and sin some more. This exploits the most powerful gene which our Cro Magnon ancestors bestowed on the males of our species. (Whether that gene is for survival or really programmed for self destruction remains to be seen). If you want to sell to the testosterone crowd, nude ladies in various poses of ridiculousness must fake orgasms while interacting with whatever you're hawking. That's how all deals get closed. Or so the ad execs insist. They're Darwinists. They know we are descended from monkeys. Haven't we all watched what monkeys do in zoos?

The Four Seasons impulse

How do we sell the crowds that are doing weekday lunches at the Four Seasons, driving up in their Urban Assault certified Range Rovers? Same deal. Just use more tastefully déshabillé cues. Advance from the blatant to the merely obvious. The veneer of civilization is thin after all. Even successful rich guys still ride on the Cro Magnon gene. They just like to pretend they've traded it in for a fat tax shelter in the Gran Caymans. Dress up your Hefner babes in elegant but suggestively transparent cocktail couture. For the older crowd, juxtapose extreme youth with deep neck lines and expensive jewelry against silver-haired svengalis. Either way, your magazine cover now will walk that fine line which speaks to both the prowling hunter and his polished alter ego that lives a double life in the swanky uptown penthouse.

The audio code
Audio upsells too. In reverse though. It attempts denial since the notion of playback in the basement sweet spot lacks all sex appeal. We advance from the raw lust of Cerwin Vega powered boom truck wattage to single-digit SET sophistication. It's how we prove our dominance over the pesky gene. Deep down meanwhile, we still long for buxom bass and ass-kicking booty. But we've officially joined civilization. Brawny subwoofers with 18-inch drivers and 1000-watt amps would instantly brand us as low-fi pimps. That's how the powers that be have stacked the deck against us. Ditto for equalizers with -- or even without -- blinking lights. For as long as we hope to retain our membership in the exclusive club of audiophilia, we must deny ourselves cheap symbols of virility. Must, must. On second thought, mini monitors carved from imported Granite really do image like sons of guns. The highlight of our twilight is upon us. Or so we keep telling ourselves while our granite cabinets match the kitchen counters and domestic harmony lurks.

The clock keeps ticking

But just like a time bomb, the gene keeps ticking. This precipitates our ongoing battle. It's between lust and intellect. We call it heroic. Someone else might call it sick. In either case, denial is the name of this game. With it come the various aberrations that define audiophilia - unending dissatisfaction. Occasionally though, a company rises to the occasion. They remind us. Sin is good. Get some satisfaction. Live happily ever after. To that end, WLM offers three models of subwoofers. They all sport vertically opposed V twins - oops, woofers. Those are of the 12, 15 or 18 cubic inch persuasion, housed in highly inert octagonal Birch ply cabinets dressed in fine veneer skins.

The thing about proper bass
These subwoofers are passive. They are packaged with active external crossovers and analog equalizers. Naturally, they also require mono bass amps. WLM recommends and will supply a compact but powerful Class D amp from the pro arena unless instructed otherwise. Fit'n'finish of the Duo Series cabinets conforms to the highest standard in fine furniture. Various veneer options, standard or exotic, are available which all cater to the penthouse.

In WLM's world however, the Cro Magnon gene is alive and throbbing. Hence cone surface area is king. So are driver efficiencies of 100dB and sealed alignments for tautest control.

In short, we're allowed to be 17 again, to install four ten-inch woofers in our souped-up Pinto. Except we're older. We do things in style now. With brains. Enter active crossovers ahead of the amplifier for direct drive.

Depending on your application, WLM provides various options to filter your main speakers or run them full-range, apply compensation to either monitors or sub, switch between various modes of operation on the fly and run bi- or tri-amp scenarios with separate adjustments for each signal feed.

This all-analog circuitry is housed in extruded aluminum boxes whose front-mounted controls -- rotary dials and toggle switches -- are of the non-intimidating, clearly marked kind. They avoid cheaply flickering lights and chintzy sliders like a plague.

In WLM's world, bass mandates discrete, purpose-designed enclosures so they can be sited independently from the main speakers. Passive networks are replaced with active circuits for better performance. Full-on adjustability for freedom of voicing is paramount to these gents' notion of customer satisfaction.

This concept -- of lasting hence real audio satisfaction relying on total flexibility to adjust treble balance, midrange prominence, bass extension and weight in situ -- is refreshing because it's so eminently practical.

Alas, the present state of hi-end audio discriminates heavily against electronic compensation and active drive. To the converted or brainwashed, WLM's insistence on these methods must seem like a strange throwback to the primitive chop shops of their youths. They were driven then by a single-ended obsession for performance while being nonchalantly oblivious to certain since sanctified commandments. Credos revolved around size and power. More of each was clearly better. No replacement for displacement. The most wattage won.

When it comes to superior bass, these teenagers actually got it right most of the way. They just didn't apply proper intelligence to the main challenge at hand. WLM is set to rectify this. They welcome back the weary who are down-trodden from the hi-end commandments. They realign them with the practical pursuit of killer bass: proper weapons, proper drive, proper control, proper integration with the ancillaries.

You probably think I'm overdrawing. I'm not. The Duo 12 is WLM's smallest sub to date. For serious purposes, dual twelves is what WLM calls the minimum. Not just any 12s though. These are hard hung highly efficient professional units whose 100dB ratings enable them to track even very small signal fluctuations without horn loading.

The opposed loading cleverly cancels mechanical resonance in the additionally very well braced cabinet. The goal is for highly dynamic, minimum overhang, low distortion bass.

Being up- and down firing creates two dissimilar path lengths, one fixed to the floor, one somewhat variable to a given ceiling. This mimics a standing rationale for stereo subwoofers - more even room loading.

Additionally, omni radiation cloaks localization cues far better than front-firing designs. This isn't pretty theory either. With the monitors actively high-pass'd at 80 or 90Hz, the sub isn't localizable in action.

To WLM, a subwoofer isn't something one simply adds as an afterthought. Designer Martin Schützenauer believes that an ultra performance system requires a dedicated bass system and should be configured thus from the start.

That's exactly how WLM packages its top systems - active drive with separate amplifiers for the mains and subwoofer or even bi-amped mains. All necessary signal paths are split with WLM's control circuitry. The provision for bass compensation of the main speaker is, ultimately, a stepping stone toward full hi/low-pass filtering whereby all information below 80 or 90Hz gets sent to the separate bass system.

This concept is far from novel. It's standard MO in the pro world where active bi-amping is a feature of many monitors to begin with. It simply hasn't caught on with the fundamentalists of hifi. Those remain dominated by puritanical notions of an absolute sound that is a fixed though abstract standard. Simply put, the recorded music we listen to has been doctored endlessly at the mastering console. That's a fancy name for nothing but a very complex equalizer. With recordings helmed by different engineers in studios around the globe, a rigidly fixed playback system with a single voicing is bound to fail. By definition, it can't be perfectly matched for the majority of such diverse albums

Enter the room variable. Add listener bias. Then consider equipment changes over time. Finally, accept our human propensity to turn even perfection into boredom once it goes static to become sameness. Variety inspired by moods or different listening levels is a fickle but cruel mistress. She must be obeyed unless you insist to destine long-term happiness with your audio system to certain ruin.

A loudness control is a very useful thing. It counteracts our biological roll-off in the treble and bass during low-level listening sessions. Stupidly, the high priests of audio have outlawed loudness controls. Ditto for tone controls. Fancy a bit more bass on a lean recording; a lot more bass for a party or to motivate yourself during a workout? Need more midrange, less treble?

We all do. All the time. Most of us simply don't know it yet. We haven't experienced the freedom that comes from such choices and adaptability. WLM's active system control is the master mind that makes this possible. It's the real brains of this operation.

The subwoofer is very impressive no doubt. But without that brain, it'd be just a pretty log with some wiggly paper ends. Seamless integration with the stereo soundstage of the mains speakers is what an uncompromised performance in the listening seat is all about. Active compensation is the key to unlock it.

All this sounds like so much gospel hogwash and spin. Until you experience it. Then it's a different ball game. What's more, it ain't complicated at all. You can even eliminate a preamp. With the optional remote control, designate WLM's system control as the master volume. Three different inputs serve exactly that purpose. Needless to say, WLM's solution isn't exclusive to their own speakers. I've already had tremendous results with my miniature Mark & Daniel Ruby monitors with add-on omni tweeter.

How does it sound? Like a good movie. Let me explain. Envision all your music CDs as the dialogue and action of a movie. You're familiar with every word, every twist of the story. Except that once the system-controlled WLM Duo 12 enters, it's as though you turned on a separate soundtrack for just the two bottom octaves.

It really seems that way. There's a sub plot to the musical story that's just as rich in nuance and wit. Putting this subwoofer system in charge of telling that part of the story makes the whole music movie a far more colorful, complex and intelligently written tale.

Much of it you've of course heard before. Enter a very strange paradox. Somehow -- I can't exactly explain how but it's patently obvious -- you can now focus separately on the back story, the stuff in the shadows and nooks and crannies as it were, down there in the bass. By doing so, the main action becomes more integrated. Of course that's what we wanted all along. The experience thereof is simply a bit different than expected. You needn't listen in "vertical stereo" mode whereby bass and remainder are discrete halves. You can shift your attention back to the blended effect whereby stereo becomes one and top and bottom meet in the middle.

If you want, however, you can experience your music now also as a movie. Action and soundtrack are separate entities. Our brain assembles them as one but we can simultaneously observe them prior to assembly, to note and enjoy certain interactions and echoes that blur in the other mode of experience and run together.

It's a very concrete yet elusive shift in perception which I haven't encountered quite like this before. It's not really about more bass quantity even though pursuing that is just a twist of the dial away. It's about a higher form of bass quality. It's exceptionally well integrated and 'of a piece'. That's the paradox. It is an organic piece of the whole. If desired though, it allows that click in the brain whereby I suddenly find myself listening in horizontal and vertical stereo. It's like hearing a complex Bach fugue and hearing all the counterpoint voices discretely, simultaneously. As soon as you think about it, you're locked out. If you can be still and keep the sides open without wavering, you are there again.

woofer mount screws
Forget all the silliness about maximum measured SPLs at 20Hz. That's for typical subwoofer reviews. That's for demolition and munitions experts. To know that the Duo 12 is weapons grade requires no more than a 3 to 4dB boost on the bass compensation dial. As the pressure builds up, you get the message. But that's not what music is about. Music is about hearing with head and heart together; to be touched deeply while the intellect can admire geometric forms and trigger into non-linear perception.

This subwoofer system enables that. And I haven't even talked about the greatly enhanced dynamics derived from high-pass filtering the mains. Nor the increased tone colors resulting from a firmer foundation. Nor the improved late-night sessions where a quick turn on the dial compensates for the Fletcher-Munson curve. There's more to this system approach than meets the eye. The flexibility is silly easy in use. Thus, it's eminently practical. If you're still pursuing perfection through the fixed voicing route wherein pucks and cones and cables and components become the nips and tucks of your permanent surgery, you should at least once experience what true in-the-moment adaptability accomplishes. Be warned though. It could ruin you for good.

21st century Neothal
What WLM has done is combine the Cro Magnon credo of brute force with the smarts of a modern education. The latter is the secret sauce that makes 'riding the gene' compulsive again even after we've refined our tastes.

It's in the active networking where the gene turns to genie. That's why it's a systems approach. That's why you can't run this subwoofer as a mere add-on. It slips into the system upstream of your integrated or between preamp and amps. Putting it there is the trick. And what, exactly, is in those little aluminum boxes of course.

Again, the concept per se isn't novel at all. It's all established
know-how. It's the level of execution combined with availability in upscale consumer hifi where we're faced with somewhat of a novelty. The sheer practicality and effectiveness of this solution is very anti snob appeal. Modern HiFi has nearly defined itself as a dolled-up hair shirt affair. All the practical features -- balance control, mono switch, tone controls, loudness control, brightness controls -- have been eliminated. One size fits all. It's a stupid straight jacket, by sadists for masochists. It wasn't always so.

The genius of Saul Marantz was fully cognizant of the need for and usefulness of premium tone controls.

He also knew how to design and build things for the ages. WLM coprincipal Hannes Frick owns the above 7T and has fully reconditioned and restored it. "Mechanically i.e. technically, I didn't have to monkey with anything. This preamp was built for eternity and the 7c tube version thereof is legendary and trades today for top coin. The 7T sounds just as good as the 7c and when I compare this 45-year old piece to contemporary hyper-expensive hi-end preamps, the latter are hard pressed to justify their existence. Our predecessors were very advanced. Dual mono attenuators weren't enough. There were high and low-frequency filters on ultra quality pots. The hammer in this unit were the brown transistors which were built into the circuit like tubes. Whenever I audition or inspect such vintage gear, I'm keenly aware just how many backwards steps we have made over the last few decades."

This familiarity with past triumphs and humility to learn from rather than discard 'em informs what WLM is on about. It's a return to proven principles that, somehow, got discarded in the name of progress. It makes our running subtext of Cro Magnon man and his peculiar obsessions doubly relevant.

For a separate riff on this theme, refer to my industry feature called Snobbery - The Disease of Disdain. To conclude, WLM's Duo 12 is more than it appears and as such, goes beyond what you might expect. As a whole system with all the necessary amplification, control boxes and cabling, it's not inexpensive. Once you experience what it can do though -- today and tomorrow and the day after when an album or mood or room or new component might warrant
a minor or major tailoring of your overall system voicing; or you plain get bored with the sound -- it could well change your perspective on what's important in audio and how to go about it. It also explains why VAS Industries would reissue the Citation Sound 1 Stereo Preamp. It reintroduces a lot of the functionality that's gotten stripped off modern preamps.

Some review engagements really mandate the workshop format whereby certain things are deliberately left hanging until the next installment or the one after that picks up again. That's because something in your overall perspective on things has changed. Yet it'll take further experiments including with other gear you may not yet have to tease out all the ramifications and confirm or qualify a mounting suspicion.

My encounter with the WLM approach to system control has me suspect that it partially or entirely supersedes the usual advantages of active over passive preamps. Handling the necessary frequency splitting line-level and unloading the two bottom octaves on a truly superior bass system already rewards with the increase in tone, body, drive and fullness for which we usually prefer premium active preamps. In WLM's case, there's an additional element. Because the Pre/Passive Control allows a bass boost for the main/monitor speakers whose knee hinges at 150Hz, you can dial in just a skoch of lift before that signal gets high-pass'd at 80 or 90Hz. A very light touch on that control can bestow the perfect kick in the power band, especially with a monitor whose smaller cabinet volume allows it to develop higher pressures in this region. Nothing gives music its sense of jump and kick as much as a fully developed potent upper bass.

This observation came in the wake of listening to the Diva Monitor/Duo 12 combo. I was using the Pre/Passive Control as master volume, thus eliminating my usual Supratek Cabernet Dual preamp. I was also running a number of non-tube amps such as the April Music Aura Note and Firenze Audio Rosso 460B battery-powered and bridged Class T amp on the Divas. I so little missed going back to my usual fire bottles in either the line-level or high-level domain that I 
wondered. Had I finally chanced upon the setup that would abolish my dependency on valves to address certain issues important to my sense of musical rightness? I've come close to thinking so before only to return to tubes, eventually and always. Thus the workshop notion. It'll take more time to settle this suspicion. But it's strong. The WLM sub/sat approach clearly is not the conventional one popularized for home theater which was primarily concerned with convenience and satellites as small as possible.

Martin Schützenauer's analog circuitry allows a diehard tube hound to enjoy an all-transistor setup because the majority of voicing issues usually fixed by valves have already been addressed - ahead of the amplifier or preamplifier. That makes what's in those components -- tubes or transistors -- seem to matter a whole lot less than before.
Manufacturer's website