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Widebander + woofers vs. widebander + tweeter. Zu's subjective 'failing'—as a long-time owner of various Zu models this term is applied fully appreciative of their many trademark strengths—has always been a lack of ultimate resolution in the 1.000-6.000Hz range. The paper-based Eminence-sourced 10.3" widebander Sean Casey and team so doggedly built their small empire on exhibits obvious resolution limits in the upper sector of its passband. With my $5.000 Essence model Zu attempted to diminish this with a TangBand ribbon tweeter. To accommodate its lower voltage sensitivity, the widebander had to be padded down. This caused Zu devotees to view this model as an unwelcome and more conventionally voiced departure from the established house sound. To them the Essence gave up vital snazz and dynamic spunk for more ordinary top-end sparkle and detail.


Reaching deep into the nano-tech bag of new chemical compounds and material treatments, Sean has since attacked the widebander diaphragm itself with various proprietary processes to drive up its performance; and implemented more far-reaching rebuilds of the motor structure. The dearer Zu models also transitioned to a technically more advanced and costlier Radian 850-based tweeter; the hookup wiring now reflects the new Event geometry; and the assembly/structure of the cabinetry and driver loading has made significant advances. To characterize the Zu sound of 2009 when the Essence launched, I'd want descriptors like feisty, dense, punchy, tonally heavy, warm but not slow, rev-happy into high SLP and somewhat vintage/old-fashioned in its general voicing to perhaps be the speaker equivalent of a powerful but older push/push valve amp.


Into this milieu the current Rethm aesthetic introduced significantly more light and sophistication. The Maarga upped the resolution game particularly in the all-important upper midband but also in bass definition. Insight as a literal seeing in was unquestionably greater. Efficiency as indicated by respective volume control settings was higher too. This suggested yet faster reflexes. The Indian speakers also extended lower into the bass and described low-down action with more and more deftly picked words. Whether a function of dedicated amplification with electronic low-pass or faster more accurate drivers, the Rethm bass was the more articulate and extended.

Where the Essence retaliated was with more pronounced upper-bass kick or perceived displacement. This created a pervasive punchier character. Think happy slugger. I intuitively associated that with the bigger driver firing straight at me to move air directly at the listener rather than elsewhere first. On edge definition aka image crispness the Indians led the field again as they also did in a significant way on soundstage articulation. Due to their generally higher illumination the sonic imagery was more teased out and in the layering/holographic sense more developed. The '16/44' Zu now felt a bit like the vintage Vandersteen 2ce—that long-ago Vandy was my first high-end speaker— against the modern '32/384' Rethm. The Essence was beefier and heavier, the Maarga more refined, striated/cut and quicker. That difference gap was noticeable. But because of that 10.3-incher's undeniably snappy impact on general proceedings, throttle-focused rockers could well prefer the Zu aesthetic. It majors more on macro shove than ultimate micro dynamics. Its lower acoustic center also generates its own saturated tonefulness. From that derives the particular Zu fleshiness which eludes most ceramic drivers and requires no thermionic injection. For the Maarga to fully blossom on tone could (at least to some folks) mean valves. Enter 300B and EL34.

Unless one owned my friend Dan's Trafomatic Vilobha 75TL monos or Berning Siegfried, the switch from Nelson Pass S2 to equivalently priced tube amps will invariably involve a trade of speed for textures. While I could personally appreciate that inner glow so prized by SETists and in full evidence with Jack Wu's Model 5 fitted with all Synergy Hifi glass, I very reluctantly let go of the grippier more energetic and lucid S2 presentation. In very basic terms it came down to how a sports car handles corners versus a sedan - taut with all the bumps; or smooth with less feel of the road.
Trafomatic Audio Aries, Woo Audio Model 5, Yamamoto A-09s
But there was more. Outdone merely by Sven Boenicke's CHF16.460/pr B10 on ultimate depth, the Maarga celebrates deep-space soundstaging at a very high level. (Having compared Boenicke's B8 to the B10, I credit the latter's absolutely spectacular ambient recovery with thousands of dollars worth of built-in esoteric but clearly efficacious tweaks. Think latest-gen Bybee purifiers specific to the hot and cold legs; Holger Stein matching networks; David's Black Wonder phase linearization circuit; three Harmonix devices on each tweeter magnet; Marigo dots; Stein Music e-pads; and Boenicke's own ingenious Swingbase).

Audiomanufacture Boenicke B10 in cherry with Swingbase and ModWright KWA-100 SE
For the Maarga there's point-source dispersion across the majority of the audible band without phase-shifting energy-robbing filter parts. There's high sensitivity. There's also that very narrow 'wind-slippery' enclosure. These all are likely contributors to that Gallo Ref 3.5-type out-of-the-box soundstaging. In this department too the triode-curve silicon-carbide static induction transistors outshone the true and strapped triodes. The valves had lower micro resolution, higher noise floors, fuzzier edging from higher THD and as a result less focus and less articulated depth layering. For those who feel drawn to the Maarga for its speed and needle-point definition, the search for the right amp if valves and a still reasonable budget are on the menu could get quite rarefied.

From my three single-ended options I most fancied the faux triodes of Sasa Cokic's EL34 Aries. On the Voxativ Ampeggio I'd prefer the Woo for its more liquid texturizing. On the Rethm Maarga the drier but more accurate Trafomatic struck the better balance. I also thought it was more extended on top than the famous but overrated direct-heated triodes. Therein lies a very relaxing rub (down). A €2.000 6wpc amp really can be all your Maargas require for true happiness. The 87dB Boenicke for example—series-connected opposing 10-inchers without filter plus single-cap paralleled 4-inch widebanders—much prefer Dan Wright's KWA-100SE muscle to Nelson Pass' 10wpc micro power. The moment real power enters the equation, the hunt for amp sophistication can get disproportionately expensive. While the Maarga's base price is substantial, a total just north of $10.000 for a pair of speakers plus main amp plus two powered perfectly matched subwoofers breaks down into greater cost effectiveness than a first glance might figure.


For those favoring a denser meatier but highly dynamic presentation with a non-existent noise floor, Vinnie Rossi's new $1.500 Signature 15 is one tailormade and very cost-effective partner. Don't let that amp's demure black box, price and simple innards fool you. It's a significant stepup from Red Wine Audio's prior class D efforts. To borrow from higher up on this page, the Sig 15 injects a whiff of Zu into the Rethm sound. Things get a bit punchier and fleshier. And you don't need a preamp but get remote-controlled volume in the bargain. It's quite the deal really!

Highlights. Having listened to speakers of otherwise conflicting persuasions over many years, it would be disingenuous to proclaim any one concept inherently superior. I've for example heard multi-driver speakers like the Aries Cerat Gladius 'outsingle' bona fide single-driver speakers. I'll thus not credit Rethm's recipe with any innate advantages going in. I'll simply list apparent strengths. If those would—seem to—tie back neatly to the augmented single-driver high-efficiency scheme, we could smile knowingly or still admit ignorance over the true reasons:
• Low-level intelligibility is perhaps the most overlooked truly vital quality a real-world speaker must possess to satisfy over the long term. Here the Maarga shines like few others. The curtain rises completely at 23:00-hour SPLs which your next-door neighbor will never notice. Rather than crank the volume to catch the contact high, the Maarga communicates at relative whisper levels. Here for example it delegates the Boenicke to second place.

• Dimensional sculpting is the difference between faintly suggested and tacit three dimensions. The Maarga scores high on wrapping your ears around the performers rather than encountering them as mostly cut-out sheets stacked at various distances from your seat.
• Ease works on the listener's side—how much subliminal effort is required to concentrate on and stay with the music—and it works with the hifi. Some speakers sound muscular. Others sound incisive. Others again seem like giant headphones, tiny details swarming like ants. The Maarga sounds elegantly easeful or easefully elegant. Listener effort is very low.

• Emotional listening is the ultimate crux of the hobby. What makes it so? If you call up dynamics and tone as core triggers, the Maarga nails microdynamics. These are the undulating tiny ripples or voltage shimmers which create inflections and meaning inside a melodic phrase. Rethm's proprietary widebander augmented by equally proprietary twin woofers also captures tone colors very astutely. This could be a function of timing where harmonics aren't divorced from their fundamentals by phase shifts. Whatever the technical reason, the Maarga paints with a very expansive tonal palette without cheating with faux warmth.
• Scale combines staging grandeur—relative width/depth—with LF coverage. Much ambient realism depends on very subtle low frequencies to properly conjure up audible space and with it the illusion of rendering your own physical walls transparent to another superimposed acoustic. Here the actively filtered isobarically loaded bass solution goes places no single-driver speaker fully can. It's not about high-impact show-off bass. It's about conveying recorded ambiance.
Vilobha monos with Voxativ Ampeggio
To inject a terse but useful second opinion, after delivering his giant Vilobha monos to Dan, Trafomatic's Sasa Cokic stopped over in Villeneuve. Owning Rethm Saadhanas stood him in good stead to assure that his 20-watt 75TL would be operationally inaudible on Dan's 100dB Ampeggios. He thus immediately commented on the Maarga. "Clearly improved driver over the Lowther." And, "this is my kind of sound, not Voxativ." The takeaway is simple. With the Maarga, Rethm designer Jacob George has made a single-driver high-efficiency speaker behave conventional, i.e. full-range and without emphasized presence region. Yet he didn't sacrifice the breed's usual virtues. Written in a few seconds, that short sentence hides 10 long years of sweat, blood and tears.


Are similar results possible from the other direction - by way of medium-efficiency more complex dynamic multi-way speakers? With the Aries Cerat Gladius an easy in-house example, I'd say yes. Yet there remain two advantages I'd still single out as distinct for the Maarga. These are low-level listening and being able to use a super-sophisticated micro-power amp like the S2. The latter for example doesn't exert proper control of the twin 10-inch woofers of the Boenicke.


Final words. A truly boutique i.e. low-volume speaker house from faraway India has managed to author its very own wideband drivers. This finally stepped them out of the negative press surrounding their prior (though heavily modified) Lowther association. Beautifully smooth without any ragged remnants, the Maarga driver has no exotic pretensions. There are no field coils, hand-made Japanese paper, exotic magnetics or expensive frame casting. Yet it ticks off all the vitals on the must-have ear list. The other coup is the active bass system. It completely obliterates all prior criticisms about bass reach and amplitude.


To underwrite this point, take Inès Adler's comment relative to Dan's planned use of a JL Audio subwoofer with her Voxativ Ampeggio. "It'll never be fast enough to integrate properly". Rethm's refinement of their own active bass system with paralleled smaller custom woofers attacks such acknowledged challenges head-on. It's when trophy ideals are courageously sacrificed at the altar of reality bites—this particular ideal being that nothing will properly mate to a 100dB widebander and who needs augmentation in the first place—that true out-of-the-box thinking begins. Jacob George's is a surprising but superb solution at the end of a very long and lonely journey. No if but or maybe, with their Maarga the company Rethm has finally arrived with all guns blazing! Check out Frederic's report on the smaller Trishna too.
Quality of packing: Very good. Each box is palletised flat and generously lined with protective foam.
Reusability of packing: A few times.
Ease of unpacking/repacking: A cinch.
Condition of component received: Flawless.
Completeness of delivery: Perfect.
Human interactions: Always excellent and open to feedback.
Pricing: Given the built-in powered subwoofers with class A/B custom amplification and proprietary drivers in a rear-hornloaded scheme; and the complex architecture of the box and its industrial design; and the completely custom widebander - fair value.
Final comments & suggestions: None. This is a completely mature product.
Rethm website
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