Ascendo M-S MKII Loudspeaker

Cutting Edge

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.