MartinLogan Montis Reserve Series Electrostatic Hybrid Loudspeaker

The Hybrid Perfected

Equipment report
Martin Logan Montis Reserve Series
MartinLogan Montis Reserve Series Electrostatic Hybrid Loudspeaker

I knew there was something special about MartinLogan’s new Montis electrostatic hybrid when I first heard it at the 2013 Newport Audio Show. For one thing, my wife wanted to linger a while and listen further. Now Danielle would almost rather eat chalk than audition audio equipment, and at this particular show decent or better sound was by far the exception to the rule. We returned to the room later that day—as much for relief as for interest—and the next day I went back myself. With each visit I liked what I heard better (all kudos, by the way, to audio veteran Dan Rosca for the setup). In due time I requested a review pair. Despite my longstanding preference for planar electrostatics—all vintages of Quad ESLs and the late, lamented Acoustats—my experience with previous MartinLogans was limited; and attractive though I found many aspects of their performance, they never quite succeeded in closing the deal as it were. In one fell swoop, the Montis changes all that: This is a really great loudspeaker.

Based in Lawrence, Kansas, where the company has been designing and manufacturing high-quality electrostatic loudspeakers for well over three decades (though manufacturing is now shifted to Canada), MartinLogan hardly needs an introduction for either its products or its technology. The Montis is one of three hybrid models in ML’s top-of-the-line Reserve Series, above the Ethos and below the Summit X, which my colleague Dick Olsher raved about in TAS 209. (The flagship in the Reserve line is the CLX Art, but it is a full-range ESL, not a hybrid.) I refer readers to that review for a thorough technical description of ML’s electrostatic technology or better still to Dick’s profile of the company in The Absolute Sound’s Illustrated History of High-End Audio, Volume 1: Loudspeakers. The Montis is almost as tall as the Summit—both around 60 inches high— and uses the same 44" x 11.3" CLS electrostatic panel. CLS stands for ML’s unique Curvilinear Line Source, which involves a gentle horizontal convex curve the better to disperse the higher frequencies, thus mitigating the narrow treble radiation of so many electrostatics (notably Quad’s). Not that it scatters the sound all around the room like an omnidirectional; rather, the dispersion is limited to approximately a thirty-degree angle, which is more than sufficient to prevent the-head-in-a-vise syndrome. The Reserve series as a whole incorporates several improvements over past ML panels, including aluminum-alloy frames of exceptional strength and rigidity, and both a physical and electrical ruggedness that make them almost impossible to damage. (Accessible through ML’s Web site is an amusing video called “Myth,” which addresses most of the so-called “problems of electrostatics,” that has one of the company’s engineers banging a CLS panel to demonstrate how rugged it is. Providing you don’t actually poke something through the stators—which would be difficult, as the perforations are small—any sort of accidental physical damage to the membrane itself would be unlikely in the extreme.) CLS panels play as delicately as any transducer on the planet, yet they also boast exceptional reliability: not since the fabled Acoustats of the eighties have I felt no anxiety about destroying a panel by driving an electrostatic as loud as I wanted, and no Acoustat was ever as efficient, easy to drive, and transparent as the Montis.

Impressive as ML’s latest CLS panels are, it may be the woofer and its associated crossover that are the real wonder here. The main difference between the Montis and the Summit is that the latter crosses over at 270Hz to a pair of powered 10-inch woofers per array for the bass, whereas each Montis has just a single powered-woofer crossed over at 340Hz. The -3dB point of the Summit is 24Hz, the Montis 29Hz. But the Montis has one considerable advance over the Summit, what ML calls a 24-bit Vojtko DSP “engine.” Named after Joe Vojtko, one of ML’s resident engineers and designers, this circuit uses digital processing to help the CLS panel and the woofer mate as coherently as possible. It was precisely this thorny matter of ultimate coherence and integration that left me unconvinced by all ML hybrids I heard before the Montis. However Vojtko has managed it. This new model is the most completely successful ES/cone hybrid I have ever heard (though I must add that I’ve not heard the Summit). Once you get the speaker optimally positioned and the rear-panel control at the right level, the integration is to my ears for all practical purposes seamless and coherence absolute, banishing any sense of listening to two different methods of propagating sound waves.

Before getting down to listening, a few more nuts and bolts. Despite its height, the Montis cuts a very svelte and surprisingly unobtrusive figure; though the aluminum-alloy frame— exceptionally rigid and solid—and the stators are black anodized, the perforations in the latter make the speaker physically transparent for most of its height, so you don’t feel as if a pair of Stanley Kubrick’s monoliths have descended into your room. There is a nominal 4-ohm impedance, but these are electrostatics, so impedance dips much lower at certain frequencies. That said, I had no trouble driving the Montis to clean levels louder than I could comfortably stand with Zesto Audio’s 60-watt Bia tube amp or NAD’s M50 integrated at 180 watts a side. Sensitivity is 91dB, helped no doubt by the fact that the woofer has its own dedicated power amplifier.

The Montis is state of the art in all the areas for which electrostatics are traditionally outstanding: it has a tonal balance that while not quite dead neutral (more on this in a moment) always sounds supremely natural and extremely smooth. It is as sonically transparent a transducer as any ever made—certainly as any I’ve ever heard, which is to say that it rivals any Quad of my experience, which includes every Quad ESL ever made. It has dynamic range that is quite beyond the capability of any Quad and for that matter any other ESLs of my experience, including Acoustats. (Acoustats might have had the capability to play as loud, but they were so damned inefficient that I doubt amplifier power existed to make it possible.) And its frequency response, especially at the bottom end, not only exceeds Quads, it exceeds many so-called full-range cone speakers with which I am familiar. Finally, it can do size to match any Magneplanar I’ve ever heard without what always strikes me as the Maggies’ tonal anomalies and discontinuities (much improved, I grant, in the latest models, but still not enough to persuade me).

What seduced my wife about the Montis was its musicality and warmth. Danielle is no audiophile—accompanying me that afternoon last year at Newport was her one concession to an audio show in sixteen years of marriage! By warmth she didn’t mean the term as audiophiles typically use it; rather, she meant that it didn’t sound “hi-fi,” as in edgy, bright, toppy, glaring, irritating, and relentlessly, fatiguingly over-detailed. In this she was absolutely correct. In fact, the Montis, as measured by Robert Greene in my room, is ever so slightly forgiving in the 2k–4k region, and above that exhibits a mild sloping response. Together these characteristics are neither gross nor obvious, and do not manifest themselves as coloration or a significant deviation from overall neutrality. The effect is rather more like a shift in perspective from, say, row A–G to H–P. This means that with recordings that are far too closely miked, which is to say most recordings, the Montis will actually sound more natural in ways that a literally accurate speaker will not. If I were to search for a thumbnail characterization, I’d say its tonal character is reminiscent of what in the old days used to be called “New England” sound: essentially neutral, uncolored, smooth, civilized, maybe a bit polite. But with one huge difference: no “New England” speaker I’ve ever heard was ever capable of a presentation as full of life and vitality as the Montis, able to scale instruments to life size and bring the room as alive with music. And no such speaker ever sounded as open and free from a box as this one.

Because the Montis has a tonal profile more or less similar to that exhibited by most really good concert halls, it almost always sounds musically right, natural, and realistic. Of course, the smart money will tell you that you should look elsewhere if you want to play rock and roll, and for many listeners that advice may indeed be smart. I don’t listen to a lot of rock myself, but what I do listen to—from Buddy Holly to the Rolling Stones—sounds great on the Montis, not least because of how big the projection is. Mick Jagger at his raunchiest certainly doesn’t come across as polite, and when the singers come in behind Cat Stevens on the last cut of Tea for the Tillerman, the effect—dynamically, spatially, dimensionally—lifts me out of my seat. And thanks to that wondrous woofer, any sort of drums and electronically generated bass are sensationally strong and clean with superb definition and control.

When it comes to classical music, the Montis’ presentation of large orchestral and choral music or opera is spectacular in scale, impact, and once again that elusive sense of realism. The presentation open outs with tremendous size, weight, and impact. The brindisi from the new Chicago Symphony Otello, conducted by Muti, is presented exactly as recorded: a concert performance with the orchestra spread out in a Cinerama-sized array, the large chorus toward the rear, and the soloists front and center. Bass response is fabulous, clarity fantastic, and dynamic range sensational. With performances that are aurally staged for recording, like the Solti-Culshaw Ring, the Bernstein Carmen, and Joel Cohen’s Sing We Noel, the Montis soundstage is so convincingly three-dimensional that I found myself wondering why anyone needs to bother with surround sound. On smaller ensembles, the same uncanny sense of transporting either you to the venue or the performers into your room obtains. One of the best choral recordings of recent years is Conspirare’s Sacred Spirit of Russia [HMUSA], which captures the spacious acoustics of a beautiful-sounding church (in Austin, Texas) to a fare-thee-well. When the small chorus sing out and the voices expand to fill the room, you’ll hear an object lesson in what loudness level in relationship to volume is all about. When the material is intimate and miked well, like some string quartets, the impression of the instruments arrayed across the room behind the speakers is spooky in its dimensionality, body, and sheer “here they are” presence.