Ascendo M-S MKII Loudspeaker

Equipment report
Ascendo M-S MK II
Ascendo M-S MKII Loudspeaker

The Ascendo M-S MKII loudspeaker from German y is one of the most unlikely sucess stories in high -end audio. When I first heard the M-S at last year’s CES I was impressed enough to ask its importer, Darren Censullo of Avatar Acoustics, for review samples. Not that I was knocked over by its sonics—not in a tiny Vegas hotel room, not after coming off reviews of two indisputably great (and quite different) loudspeakers in the MBL 101 E Radialstrahlers and the MAGICO Mini mini-monitors. The Ascendo was certainly promising, but the truth is I was as much curious about how the thing worked as how good it would end up sounding in my room—it was and is so damn improbable. The M-S’s tweeter is one of the chief oddities about this odd duck. A horn-loaded monopole ribbon housed in a tall, piano-black, rectangular box, it sports a prodigious appendage—a long, solid, channeled and graduated in millimeters) stainless steel tube attached to a stainless-steel plate set in the rear of the enclosure. This tube is made to slide into a hollow stainless-steel holder mounted high up on the Ascendo M-S’s massive chrome-plated stand. Once the tube is fitted in the holder, the entire tweeter-enclosure can be moved forward and back more than a foot in either direction, then secured in place by two massive setscrews. (Because of the tweeter-enclosure’s eccentric shape and weight-distribution, sliding it in its holder is a two-man job, as is mounting the large, hefty woofer enclosure—for which, see below.)

Why did Ascendo make its tweeter so adjustable? In two words, “time alignment.” Using a tape measure and the chart printed in the instruction manual—which cross-references the distance between your listening position and that of the woofer box and the distance between the floor and your ears—you can calculate the precise spot on the graduated rule of the tweeter’s mounting tube that will ensure perfect time-alignment of the tweeter, mid/bass driver, and subwoofer at your listening chair—no matter what size your room, where in it you sit, how far away you are from the speakers, or how high or low your chair or sofa. You then slide the entire tweeter-enclosure to precisely that spot and fasten it in place with the setscrews.

The Ascendo’s highly adjustable tweeter is only one of its singularities. Below the suspended tweeter-enclosure is a much larger, piano-black, rectangular box concocted of MDF and bitumen, which “hangs” at its rear on a dimpled support post welded to the main strut of the speaker stand. In front, the speaker rests on two special composite-material feet, which sit, in turn, on the big stainless-steel footers of the stand. Mounted in a sealed-box sub-chamber at the top-front of this hanging garden of an enclosure is a newly designed SEAS 8" paper-cone mid/bass driver with a big aluminum phase plug in its center. (Yes, you read that right—a paper cone.)

Directly below the mid/bass unit is a port that, at first, makes you think that the Ascendo M-S is an outsized vented two-way. In fact, the port has nothing to do with the 8" acousticsuspension mid/bass driver. Near the bottom of the same massive box that houses the mid/bass driver, invisible to the eye, is another large driver—an 11" Eton “Hexacone” subwoofer (a Hexacone driver has a diaphragm that combines a core of honeycombed Nomex with front and back layers of Kevlar)—which, like the mid/bass cone, is also mounted in a sealed sub-enclosure. Crossing over to the mid/woof at about 80Hz, this subwoofer fires up into the large tuned sub-chamber above it and then out through the front port—a configuration known as “bandpass bass.”

A ribbon tweeter, a paper-cone acousticsuspension mid/bass driver, a Hexacone bandpass sub…how in the world could such a concatenation of drivers and drive systems sound like a single cohesive sound source, rather than a multitude of separate  sources, each with its own distinct signature?

Well, here’s how.

Ascendo’s chief engineer, Jürgen Scheuring, who is a Professor of Physics and one very smart cookie (Ascendo has won a great deal of financial support from the German government and also makes a celebrated room/speaker measurement system—Room Tools—used by DG and German BMG, among others), tells me that the ability to precisely time-align the ribbon tweeter is one of the chief reasons the M-S doesn’t sound incoherent, like every other speaker I’ve heard that has attempted to mate a ribbon or electrostatic or planar driver with a cone driver. In addition, mounting the ribbon in its own enclosure (with also houses the crossover of the loudspeaker) mechanically decouples it (and the crossover) from the big mid/woofer/ subwoofer box and the floor.

Though the paper-cone mid/bass driver looks “conventional,” even plebian by MBL or MAGICO standards, it was carefully selected by Scheuring and his Ascendo design team for its high speed, low distortion, and lack of “material” coloration. The choice of a sealed box enclosure was made to further enhance speed, linearity, and low levels of coloration. As for the M-S’s low end, a bandpass woofer can produce very fast, very deep bass from a relatively small driver in a relatively small enclosure (the MBL 101 E uses one), but unless artfully implemented bandpass bass can quickly become wildly time-and-phase incoherent outside its passband, causing group delay in the crossover region. To minimize this problem, Scheuring and his team employed two patented techniques they call “dynamic-current-damping” and “S.A.S.B” (semi-symmetrical bandpass).

I will allow Scheuring to explain: “We have a speaker for the mids and upper bass in a sealed space and a woofer that looks similar to a bandpass for the very low end. The trick is to design the impedances of these two speakers, including the crossover and box volumes, so that they are damping each other electrically.

“Normally a bandpass woofer is designed symmetrically, meaning it has a rising edge in frequency response on the lower side, a plateau in the working area, and a rising edge on the high side. Ascendo takes a different tack. We use a third-order high-pass crossover at an unusually low crossover point from the “outside” mid/bass driver to the “inside” woofer. Though low-pass crossovers aren’t typically employed in a bandpass design, our inside woofer also uses a second-order crossover to couple it to the outside mid/bass driver. The result is very good electrical damping between the two drivers, which means the bass is very fast, phase behavior is very good in the crossover region (there is no step in the group delay), and, due to the bandpass design, there is acoustical damping below the tuning frequency (which also speeds up the bass compared to a ported design, which completely loses control below resonance)—all the advantages of a bandpass woofer without  the disadvantages of high group delay in the crossover region.”

Got that?

Well, if you don’t, try this: Scheuring modeled the M-S on the highly time-and-phase-coherent sound of the Quad electrostat and, by Gott, that’s what his speaker sounds like—a Quad with killer dynamics, killer extension in the bass, and even sweeter, slightly more extended treble. I don’t want to let this cat out of the bag too soon, but of all the speakers that have come through my listening room over the past ten years—including the MBL 101 Es and the MAGICO Minis—my little listening panel, which has heard ’em all,  preferred the Ascendo M-S’s.

It’s easy to understand why—despite their weird “this-can’t-possibly-work” looks, the MS’s are simply great sounding. They do virtually everything right and very little wrong. Thanks to Schuering’s ear and electromechanical alchemy, the M-S’s sound sensationally “of a piece” from top-to-bottom (very Quad-like, indeed), are gorgeously rich in tone color everywhere they play, image with natural size and dimensionality, have unusually good deep bass (down 3dB, referenced to 1kHz, at 28Hz in my room) and sweet, soft, quick, deceptively detailed treble, are very nearly as dynamic as those kings of lifelike dynamics, the MBL 101 Es, and register changes in preamplification, amplification, front end, and source with considerable transparency.

They are also—and this is the notch they fit in—equally good on all kinds of music at any and all volume levels. Unlike the MAGICO Minis (without subs), the M-S’s do power music with authority. Though they don’t have quite the subterranean extension of MBL 101s, they go more than deep enough to reproduce synth, 5-string bass, bottom-octave piano, contrabassoon, bass drum, organ, and full orchestra with lifelike power, pitch, and color and, unlike the 101s, they don’t have to be jacked up to loud levels to strut their stuff.

In validation of Scheuring’s claims of superior time-and-phase coherence from the bass through the lower mids, the M-S’s also have simply remarkable pace, making the tempi of every kind of music crystal clear and turning good rock numbers (and even certain lightclassical music) into irresistible toe-tappers.

The Acendos are excitement machines. You simply can’t listen to them playing back Janis wailing about how she’s gonna “Try just a little bit harder” [Columbia] or Carlos Kleiber and the Vienna Phil playing the Fledermaus Overture [Columbia], without pounding your feet, moving your ass, and feeling the urge to get up and dance. The MBL 101 Es are the only other speakers of recent memory that have had this kind of electrifying effect and, for all the other virtues of great hi-fi, that direct connection to the pulse of the music—that feeling of being overtaken, bodily, by joy, without willing it or struggling for it—is, ultimately, the chief thing this hobby is

At the same time, and almost magically, the Ascendos (here a bit less like MBLs and a lot more like Quads) are capable of  extraordinary delicacy of timbre and texture, sounding simply gorgeous on small-scale music, and particularly lovely on strings (including guitar) and voice. To hear their combination of pace, dynamic power and nuance, extension, low-level resolution, and timbral beauty on something like the difficult but extremely well-recorded Schnittke Quasi una sonata [EMI], with its combination of extreme fortissimos and extreme pianissimos played in virtually every form of staccato and legato known to man, is something to behold. Likewise, the M-S’s handling of the pizzicatos throughout the Czech composer Petr Fiala’s nifty neo-Bartókian Third String Quartet [Panton]—is there, I wonder, a string quartet that has had a great influence on twentieth-century chamber music than Bartók’s own incomparable Third?—and of the wonderful diminuendo in the Allegro feroce, where the first violin seems  to run screaming off into the woods, is simply marvelous.

Speakers that can combine the sheer dynamic excitement of the MBL 101 Es and the subtle grace and nuance of the Quad 57s are rare on the ground. The Ascendo Ms do just this. And so, I’m sure you’re thinking, I should agree whole-heartedly with my listening panel and name the Ascendo M-S’s primus inter pares (first among equals).

The trouble is I don’t agree whole-heartedly. I agree half-heartedly. Here is the thing: The Ascendo M-S’s are capable of sounding as beautiful, dynamic, nuanced, lifelike, and engaging as anything I’ve heard. For the way they can connect you to the pulse of the music—any music—they are worth every penny Ascendo asks for them (and then some). But…they aren’t perfect. For one thing, in comparison with the MAGICO Minis—whose neutrality is, thus far in my experience, unsurpassed and whose ability to disappear completely into a wide, deep soundstage, within which they conjure up extraordinarily lifelike semblances of vocalists and instrumentalists is nonpareil—the Ascendos sound just the slightest bit dark and boxy. The slight darkness of the M-S’s balance can actually be explained via quasi-anechoic measurements (which I conducted with Jürgen Scheuring himself, using his own Room Tools software). Though the M-S’s measure within ±2.5 dB of ruler-flat from below 30Hz to above 12kHz and aren’t at all “jumpy” (full of little dips and peaks) anywhere, their response does rather fall into two plateaus, one of which is “up” about 2.5dB (vis-à-vis 1kHz) and the other which is down the same amount: A flat but slightly elevated bass and lower midrange plateau is followed by a sharp dip down at 1k and another flat plateau that is “down” about 2.5dB, extending out into the high treble, which then rolls off steeply above about 12–14kHz.

Now this measurement both is and isn’t a true reflection of the Ascendo M-S’s potential in a larger room than mine—and shows, to an extent, the limits of quasi-anechoic measurements via a single microphone with speakers whose drivers are widely spaced. Raising the test microphone closer to the ribbon tweeter proves that its response is actually extended well into the ultrasonic range (as one would expect of a ribbon).

Nonetheless, from my listening seat, which is situated well below the elevated tweeter (as was the test microphone), the speakers do sound a bit dark overall—weighted more toward the bass and lower mids and less toward the slightly softer and less hard-hittingly dynamic, although still gorgeously colored and detailed, upper mids and treble. Just as the anechoic measurements suggest.

The speakers’ slight boxiness, which limits soundstage width—the Ascendos when aimed at your listening position (as they should be for perfect tweeter time-alignment) do not image much “outside their boxes,” although they do spectacularly well in depth and height in the space between their enclosures)—isn’t a matter of diffraction effects or box resonances; it is, rather a sense that there are boxes “there,” like walls, at either side of the ’stage. In other words, unlike the Minis or the MBL 101 Es, the Ascendos do not disappear completely as sound sources.

Understand that instruments aren’t “pinned” to the drivers or the separate enclosures of the M-S’s; they float free of the boxes in the space between them. It is just the slight tonal darkness and the way the enclosures limit the width of the stage that make the boxes more noticeable. In a bigger room, where the speakers could be more widely spaced, or angled less directly at the listener, this would be ameliorated.

So where do the Ascendos stand in my hierarchy of top-notch loudspeakers? The MAGICO Minis are a connoisseur’s  speaker—and, because of their unparalleled neutrality, extraordinary resolution, and terrific dynamics, a superb reviewer’s reference. They will tell you more, more honestly than anything else I’ve yet heard, about what is on a recording, and, provided the recording is first-rate, will reproduce it with the highest realism. They will also tell you what is upstream of them with greater honesty than any component I’ve had in my home. That said, they are limited in the bottom octave, require a goodly amount of power to drive, and, compared to either the MBL 101 E or the Ascendo M-S’s image with slightly less-than-life-size height. (Be aware, however, that I will be reviewing the Minis with an exceptional subwoofer system that may  well eliminate these few reservations—resulting in a legitimate “super-system” that costs less than the MBLs or the Ascendos.)

The MBL 101 Es are the purest examples of excitement machines I’ve ever auditioned in high-end audio. From top to bottom, they bring every kind of music to irrepressible life, with dynamics and pace that light up your body and lift your spirits—the way music itself does, heard live. In these, perhaps most key, regards, they are the best loudspeakers I’ve ever heard. They also disappear into the soundfield as completely as MAGICO Minis, throw an even larger soundstage than the Minis (although their center-imaging is slightly vaguer than the Minis), and are the finest speakers for listening to off-axis in the world. That said, they take a tremendous amount of power to drive to their best (thriving on MBL’s own very expensive  amps), are not quite as neutral (or as neutralsounding) as Minis, and because of their peculiar power requirements are not as transparent to sources as Minis or Ascendos. (The MBLs tend to tell you what they thrive on, and not what the other stuff sounds like.)

As for the Ascendos, they are a nice combination of fidelity and excitement—a cross between Minis and MBLs. They deliver a high
measure of the same sonic thrills that the MBL’s do par excellence—truly lighting up your body with musical pleasure on any kind of music. At the same time they can play softly with a great deal of the nuance, loveliness, and superfine resolution of the MAGICOs—and with a good measure of the same “realism.” Yes, they are a little dark in overall balance (so are the MBLs). But they are easier to drive than either of the other two speakers (particularly the MBLs), have more natural soundstage/image height than the Minis, and are slightly more transparent to sources than MBLs. (The Ascendos do prefer to be tri-wired, BTW, and are equipped for same, so they will cost you a bit more in cabling.)

I don’t think you could go wrong with any of these three superb loudspeakers. Which one is right for you is something you’ll have to decide for yourself, although I’ve already told you which one my listening panel picked.

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