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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 Valve HiFi I2A3; Eastern Electric M520
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, Pre/Passive Control, Bass Control
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: starting at €13,100/pr passive, add €200 for passive/active switch; €3,850 System Control V with full-range switch
Our two prior reviews on WLM's Diva Monitor and Duo 12 subwoofer covered the history, design philosophy and principals of this exciting Austrian firm in great depth. Intended as comprehensive companion pieces to introduce the company, these two writeups deliberately focused on the entry-level speaker model but tracked its usage conversion from fully passive to semi active to finally system-controlled mode as one would upgrade in stages.


Semi active refers to the insertion of an active analog contour circuit into the low-level signal path. This selectively boosts the low bass performance of an otherwise passive speaker, i.e. one whose crossover resides conventionally inside the speaker box. With the Diva Monitor, it translates to downshifting its F3 (which port tuning and box volume set at 55Hz) to maximally 32Hz. The 10" hard-hung Eminence driver is easily capable of this added reach and excursion. Without electronic compensation, the box alignment plainly is not. Forced equalization however elegantly overcomes this physical limitation. It simply places consecutively higher burdens on the amplifier depending on how much bass boost is chosen.

Semi-active drive requires a little black box. It's actually silver and called Diva Control. It can be run through a tape loop or otherwise between source and integrated amp or preamp and power amp. With a single set of i/o ports, Diva Control is outfitted with a clearly marked attenuator. It can maximally boost by 12dB at 30Hz. The knee or kick-in of compensation hovers at 150Hz. Above that, the signal is passed 1:1, passively and without any processing. Presto, near full-range performance from a conventionally sized stand-mount monitor. Another Diva Series upgrade within this semi-active WLM scheme is called Pre/Passive Control. That box of double height replaces Diva Control. It adds a master volume, 3 inputs and the option for remote volume. This can eliminate a conventional preamp altogether. More importantly, it adds sat/woofer mode and with it, a low-pass filtered output which can slave the Bass Control to the circuit.

When the P/P Control switches from full range to sat/woofer mode, its signal path is split into discrete high and low paths above and below either 80 or 90Hz. The Pre/Passive Control remains assigned to the monitor or floorstander while the Bass Control with its own master attenuator and analog contour control takes charge of all subwoofer settings. For the passive Diva Monitor, this scheme maximizes WLM's core belief that peak loudspeaker performance requires active crossovers and dedicated bass systems. However, the Diva Monitors lacks biwire inputs and the option to run it with its inbuilt frequency divider circuit bypassed. Hence Diva Monitor cannot be converted to fully active drive. That option remains exclusive to its costlier siblings in the Reference and Signature lines.


Those can do fully active. For that, the passive tweeter contours otherwise on the backs of the speakers get disabled and duplicated inside the active outboard circuitry dubbed, very sensibly, System Control. The same goes for all the passive filter parts. Fully active drive means a speaker without any components between an amp and its voice coils (an empty box, essentially). It seems obvious that you couldn't order a passive model with inbuilt crossover and later convert it to active mode. Ha, but you can. For an extra €200, you can order the conversion switches upfront which, once engaged, completely bypass the internal filters. 8 out of 10 WLM speakers today are sold with this feature. Either way, it means biwire terminals (the Austrians only make two-ways). For the activated models, it also means the external crossover brain and of course four amp channels to drive each tweeter assembly and mid/bass driver separately.

Active drive comes in two flavors - with or without subwoofer. Most customers probably won't add a subwoofer to the floorstanding 8" Lyra or 10" Viola models which will do 25Hz with active compensation. Subwoofers from WLM's Duo range are mandatory if the Aura or Grand Viola monitor models are to be maximized (and optional for those inclined to push their floorstanders to the limit by filtering out the bottom two octaves). Lastly, WLM's phase acoustic corrected PAC twin-tweeter systems are available in Reference and Signature trim. The former is retroactively upgradeable to Signature level (WLM gets the standard PAC back after upgrading you to the Super-PAC). The difference between these tweeter systems is size -- the Super-PAC is plainly bigger -- and parts and wire quality. Out of 100 raw drivers, WLM can only craft four to five Super-PAC modules. They rely on extremely close-tolerance driver matching among other things.
Designer Martin Schützenauer is understandably tight-lipped about his PAC invention. That's relevant also because he's turned down more than one request for OEM contracts and others to outright sell his technology to corporate competitors. All we know about PAC is that it's a wide-dispersion twin-driver affair with wave-guided dome tweeters and sophisticated phase compensation to create, from two speakers, one virtual claimed point source in the room. Fully optimized PAC performance relies on a predetermined ratio of speaker width and listening seat distance plus proper PAC alignment with the seat. This alignment is set up with an included directionality jig.


To recapitulate, what your not inconsiderable layout of cash for the necessary cabling, amplification and WLM parts buys you in fully active system control mode with subwoofer integration is complete - um, control. Instead of flying coach with a stranger determining your ride and final destination, you become your own captain. You control THD and voicing behavior by selecting which amps to strap to which drivers. You steer relative treble, midrange and bass balance and linearization. You even manipulate HF phase behavior to compensate for highly reflective or absorptive room behavior.
To fully appreciate all the implications requires a big step backwards to reflect on our usual audiophile malady. All of us season the final sound in our rigs and digs to our liking. Cables, accessories and components become our de facto tone controls. Sadly, these controls are non-linear and non-specific. They don't merely address one issue, say a desired 1dB of treble cut. Invariably, they affect something else too which, once the novelty of the first fix wears off, requires another address. Predictably,
that new solution won't merely correct the previous problem. It'll create a new one. It's two steps forward, one back - at best. Often it's nothing but a lateral move, one ill traded for another. Hello upgraditis with its omnipresent specter called permanent discontent and various limitations of one sort or another.
Monitors with pro roots such as the PMC AML-1 make steps in that direction should you fancy Bryston amplification in their instance. That's what PMC built into these monitors. To broaden personal voicing options requires not merely active and adjustable crossovers. It calls for freedom of choice in amplification components. Enter WLM's active speaker models. They're called active not because they stuff all amplification and compensation circuitry inside the box. They're called active because they rip everything out of the box. It's the only way to give you full control. It ends up with active tri-amping of treble, mid and bass systems; and comprehensive tuning options for all three bands.


As you gather your wits from this all-out assault of constitutional freedom -- delivered and not just promised -- you'll eventually retort, feebly but audibly. Doesn't such flexibility render a speaker system essentially unreviewable? Bravo, you've got it. That's the whole point. Don't suffer someone else's idea of good sound. Dial your own. Naturally, this won't prevent us from reviewing exactly such a system. It's simply fair and common sense to precede any such endeavor with the obvious: if all this flexibility really worked as advertised, we'd have to end up with an unqualified rave of a review. It's unavoidable. Unlike most such raves, however, it'd also mean that one man's idea of perfection -- relative for the money; or absolute as non-toppable -- could finally also be another man's or woman's.


Enough preamble. With this third review in our WLM series, I wanted to jump straight from the entry-level Diva offering to the Austrian's very best effort. What exactly that entails is somewhat debatable of course. It clearly means separate subwoofing. Whether to pick the Duo 12, 15 or 18 with their opposing drivers will primarily depend on room size. For my own room, the Duo 12 had already proven more than enough. To my mind, WLM's very best then meant replacing my Divas with the Grand Viola Signatures.

In fully active tri-amp mode of course, System Control bandwidth-limits your main speakers to 80Hz-up coverage. Why pay for possible 25Hz extension from a floorstander? I'd evaluate the Grand Viola Signature in passive, semi-active, fully active full-range and fully active + subwoofer modes. I'd also compare the Diva Monitor with and without compensation against the GV passive to report on the added bass weight the floorstander might demonstrate.


What I expected were Diva-type dynamics and tone (after all, the mid/woofer is very similar) but a rather more spacious and holographic treble in the vein of Anthony Gallo's CDTII or perhaps an omnipolar mbl tweeter. Because active biamping would allow for any number of amplifier combinations from the choices I'd have on hand -- say Yamamoto A-08S on the Super-PAC from 800Hz on up, Melody Valve HiFi I2A3 on the mids -- I also expected further textural refinements. Unlike passive drive, active direct-couples the amp to the transducer. This transmits an amplifier's sonic signature most directly and uncut. Now I could bandwidth-limit my amplifiers and deliberately select the optimum ones for the respective tasks.


Co-owner Hannes Frick described the rationale for WLM's comprehensive choices as follows: "Our Diva models are passive but can be run semi-active with bass compensation. Our Aura, Lyra, Grand Viola Monitor and Grand Viola can all be driven passive, semi-active or fully active. Standard trim is passive. This includes the semi-active upgrade path via Passive or Pre/Passive Control. Further, there's the stock tweeter contour circuit with stepped attenuator (it's a continuous wiper with our entry-level Diva models) and a possible -3dB attenuation of the fundamental box tuning frequency to accommodate acoustically handicapped rooms. This inbuilt flexibility even in standard trim prior to fully active conversion is an outgrowth of my prior hi-end retail existence. Even the most expensive speakers I sold then required add-on compensation to adapt to their final room placement in the customers' homes. At the time I relied exclusively on passive parametric tube equalizers from Manley Labs, Avalon or Tim de Paravicini. The only problem with that? I had to personally adjust these equalizers. They were too complex and intimidating for my customers.

"For my own WLM speakers, I wanted the same kind of flexibility but in far easier and more intuitive form. Hence our optional passive/active conversion switch which, ultimately, leads to our mega brain called System Control V which has completely replaced my prior reliance on expensive EQs for about half the cost. I used to explain the difference between passive and active drive in automotive terms. Passive means you step on the gas first, then react with the steering wheel. Active drive means you steer first, then give gas appropriate for that direction. With System Control V, you can mix and match amplifiers or integrateds and you will always obtain perfectly integrated performance.


"For the PAC systems, I usually recommend a premium low-power triode such as a 2A3, 300B or 211. Since the tweeter high-pass with the Grand Viola floorstander and monitor sits at 800Hz, the quality of such an amplifier is remarkably important and dominant. For the midrange, 50 - 100 watts of tube power are ideal but 15 watts are sufficient especially for smaller rooms or whenever a Duo subwoofer handles the bass. Finally, System Control V offers remote control for the tweeter and bass settings and in conjunction with the Pre/Passive Control, can even adjust the master volume from the seat. More flexibility and freedom really are not possible." Indeed. That's not marketing spin but simple fact.