Rethm Maarga Loudspeakers, Full Range Driver and Active Bass
Very good condition with original packaging.
Hi-fi is like cake. Most people enjoy listening to music, and most people like cake.
People who like cake tend to like different things about it. Some people like a flourless cake, some people like a fluffy angel food cake, and some like a cake loaded up with little pieces of carrot and God-knows-what-else. People who like hi-fi also tend to like different things. Some like punchy, forceful sounds, some like realistic, natural tones, some like texture and color, some like "air," and some like to hear things go whooshing from one speaker to the other. It's all okay.
If hi-fi is like cake, amplifier power is like sugar. It has its place. But when people thought it was abundant, cheap, and harmless, they went whole hog on it, minimizing and even throwing out other ingredients because, hey, sugar is cheap. And fun. And harmless.
But there exists an entire movement devoted to low-power amplifiers, the idea being: A low-power amp, with its lower parts count and simpler architecture, stands a chance of being faster, more nimble, and more transparent to the source—ie, more capable of getting out of the way of the music. And with that movement comes a complementary interest in loudspeakers of greater-than-average sensitivity and efficiency—a genre that, to some hobbyists, reaches its pinnacle with the full-range (or at least quasi-full-range) driver: crossoverless, fast, and typically sensitive, not to mention elegant.
A somewhat early participant in the modern (footnote 1) high-efficiency speaker movement—their first commercial speaker, which I wrote about in Listener (footnote 2), debuted in 2000—was Rethm, whose products are manufactured in India. At that time and for more than a decade after, all Rethm loudspeakers had two predominant characteristics: They were designed and built around Lowther full-range drivers—high-sensitivity things with lightweight paper cones, powerful magnets, and almost unimaginably small voice-coil gaps—and those drivers were loaded with enclosures made from segments of fiberglass pipes.
The pipes remain, but the Lowther drivers have been replaced by full-range, Lowther-like units designed and made by Rethm: lightweight twin-cone paper diaphragms, pliant foam-rubber surrounds, neodymium magnets, the works. Those characteristics and a good many more are embodied in the recently redesigned Rethm Maarga ($10,750/pair)—the third distinct version of this midline product.
The new Maarga—the name means "the path" in Sanskrit, especially as it applies to the path followed by an Indian classical musician as he or she makes the journey from beginner to virtuoso—stands 41.2" tall and measures 22" deep and a scant 7.5" wide. Included with each Maarga are four auxiliary feet, which add slightly to its height; each foot comprises an upper and lower metal disc, both 2" in diameter, with three ball bearings between them. (Dimples are machined into the "mating" surfaces of both discs, to keep the balls in place and allow them to do their vibration-isolating thing, à la Symposium Acoustics' Rollerblocks and similar accessories.)
The Maarga's full-range driver is 6" in diameter, with a parchment-like paper cone and a 2.5" "whizzer" cone of the same material, the latter for propagating higher frequencies. At the center of the whizzer cone, which bears a ring of six evenly spaced perforations, is a vaguely spade-shaped (as in "ace of") metal phase plug. The driver's mounting rim is obscured by a trim ring, made with a great many perforations of its own, said by designer Jacob George to help ameliorate high-frequency diffraction effects.
The structure to which that driver is fastened comprises three sections of fiberglass pipe, all with an outside dimension of 7.25". These are cemented together to form an inverted U, which appears to have a total length of 80", give or take—but this isn't a simple case of throat (driver) at one end and mouth (listening aperture) at the other. Rather, the driver is fastened to the front of the upper transverse pipe, which in turn leads to the rear descending pipe, which is open at the bottom—yet, directly below the driver, there is also a front descending pipe, also open at the bottom (although a close look reveals that one half of the tube is occluded just above that opening). Sandwiching the U are a pair of nice-looking side panels, the outer surfaces of which can be ordered with wood veneer or black acrylic. My review loaners bore the latter.
Rethm describes the Maarga's enclosure as a horn-loaded labyrinth. Traditionally, such a thing would require a gradual increase in its cross-section, from throat to mouth, in order to achieve the acoustical impedance transformation required for a true horn effect—yet there's no outward evidence of such in the Maarga's enclosure. It seems possible that a horn effect is achieved via structures concealed within the fiberglass pipes, but I would also guess that the Maarga's enclosure functions as a quarter-wave pipe. For the record, 80" correlates with a quarter wave at 42Hz, which is within spitting distance of the low E string of a bass guitar. Just sayin'.One thing that's not in question: The Maarga's bass frequencies are handled by two 6" × 9" woofers, driven by a well-hidden internal amplifier and loaded isobarically, with only one woofer firing into the room and the other mounted directly behind it, firing into a sealed chamber. Both drivers get the same signal from the user's amplifier, but the innermost driver isn't meant to be heard: Its effect is to create for the outermost driver a loading chamber of variable pressure. During rarefaction, the front driver's cone excursions are accompanied by the same in the rear driver, which serves to trick the audible driver into working as though it were loaded by a much greater volume, thus allowing it to behave as it would in free air, but without dipole cancellation. (Here, the restorative characteristics of the drivers' elastic surrounds and spiders are not dispensed with but rather fortified, electrically; isobaric loading is, in a sense, Acoustic Suspension with brains—which is to say, Acoustic Suspension with greater and more consistent control over the woofer's operating conditions and with less susceptibility to changes in compliance as the driver suspension ages.)
The internal amplifier that drives those two woofers is based on a Hypex class-D module and is specified as providing 400W. At the bottom of the rear descending pipe is a curved panel that includes a pair of banana sockets for connection to the user's amplifier and an IEC socket for the amplifier's AC cord, plus four small control knobs: an on/off switch; a ground-lift switch; a bass level control that goes from Lo to Hi; and a crossover frequency control that goes from 60 to 240 (Hz) with a detent at 120.Once in my system, the Maargas brought to it a combination of strengths and weaknesses very different from those of my Altec Flamencos and DeVore O/93s. The Rethms were "airier" and more open than either, with spatial performance that was also superior (especially relative to the Altecs): Images of instruments and voices were more distinct from one another than I usually hear at home, some addressing me from a stage of greater-than-average apparent depth.
With their bass range dialed in for optimal performance in my room—with the crossovers set at just above the 120Hz detent and the bass volume similarly a bit higher than halfway—the Maargas offered from most recordings sound that was well balanced from top to bottom. Yet I was a little surprised that certain recordings—especially those with a slightly hot or pungent EQ—made the Rethms seem unforgiving. One such was the recording by the Amadeus Quartet of Schubert's D minor quartet, "Death and the Maiden" (LP, Deutsche Grammophone 138 048). In the opening bars, the violins sounded almost strident, so much so that I had to take off that record and put on a different one—the same piece by the Juilliard String Quartet (RCA LSC-2378). Here the Rethms did a better job, presenting the strings with color and realistic, natural-sounding texture, and giving good measure to the room sound during such phrases as the cello's pizzicato notes in the second movement.
The Rethm Maargas are musically light on their feet, offer good—and easily adjustable—bass extension, and look like nothing else on the market. (And, as we've seen, their customer support is admirable!) For the low-power amp devotee who wants something out of the ordinary for a less-than-painful price, the Maargas very much deserve an audition.
Description: Floorstanding loudspeaker with a single horn-loaded full-range driver and a pair of powered, isobaric-loaded woofers. Drive units: 8" twin-cone driver with 25mm-diameter voice-coil and high-compliance surround; two 6" × 9" paper-cone woofers. Frequency range: 28Hz–20kHz. Sensitivity: 98dB/W/m. Nominal impedance: 8 ohms. Minimum required amplifier power: 2W.
Dimensions: 41.2" (1035mm) H × 7.5" (190mm) W × 21.6" (550mm) D. Weight: 62lb (28kg).