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This review of the Ascendo System F first appeared in the November 2009 issue of fairaudio.de and can be read in its original German version there. It is herewith translated and presented to an English-only audience through a mutual syndication arrangement with fairaudio.de. As is customary for our own reviews, the writer's signature at review's end has a link below it to his e-mail should you have questions or feedback you wish to send. All images contained in this review are the property of fairaudio.de or Ascendo - Ed.

 Reviewer: Ralph Werner
Equipment: Sources: Analog – deck - Acoustic Solid MPX; tone arms - Phonotools Vivid-Two, SME M2 12- inch; pickups - Denon DL-103, Ortofon MC Rondo Bronce, Zu Audio DL-103; digital -audiolab 8000CD, HIFIAkademie cdPlayer
Amplification: Analogue - Aqvox 2 CI MKII; preamplifier - Octave HP300; power amp - Electrocompaniet AW-180; integrated amplifier - Lua 4040 C, Myryad MXI 2080
Loudspeaker: Quadral Rondo, Thiel SCS4, Zu Audio Druid mk4
Various accessories, cables & rack...
Review component retail: €12.700 with plinth, €11.800/pr without plinth

"Good grief, a pesky piano – here goes the photo session" was my first reaction when I peeled out today’s tester from its carton, the System F floorstanding speaker from Ascendo. While high-gloss black does appeal to the sophisticated eye, cameras balk. You simply will have to make do with my best attempts on that count…


A good year had passed since we clapped ears on Ascendo’s biggest model in their smaller C-Series, the C8 Renaissance. This time it’s about the latest and smallest entry in the Schwabian’s big line, the System Series. With a fighting weight of more than 50kg per and a sticker which starts at €11.800/pr, ‘small’ is necessarily relative - relative to the three bigger Ascendo systems; and relative also to room size.


The maker intends the F for small to medium spaces – up to 100 cubic meters to be precise. At a meter sixteen including plinth, this model isn’t exactly a giant. It remains very living-room friendly. Gymnasiums would of course best be energized with something else but 95% of all living rooms should prove copasetic. As would mine. I hoped.


While cosmetics are understated, Ascendo’s System F packs a number of technical tricks. Let’s inspect those systematically. To begin with, this is a three- or four-way design depending on whether the rear-firing TOS unit is activated…


Tech: ... or not. More on that later. One not externally visible driver hides inside and covers the lower octaves from 31 – 90Hz. This woofer is a 33.5cm paper-cone Vifa unit with magnesium basket.


The same supplier provides the external mid-bass which scales back identical ingredients to 22.5cm. For the treble, material shifts to fabric, diameter to 28mm and origin to Seas. Swans supplies the rear-mounted magnetostat. Rather than indulge in esoteric parts posing, Ascendo developer Herr Norbert Heinz prefers to cite "first-rate standard drivers" and focuses instead on implementation and in-house engineering solutions. Hence their brochures and web pages pack peculiar acronyms which elude immediate comprehension. For the System F, all of this boils down to five specific terms. It begins harmless enough with:

1/ Modular assembly/decoupling and resonance attenuation: The System F comprises at least three parts when—as I’d do already on aesthetic grounds—the plinth is counted individually. Said base contains an inner support element which receives the floor spikes; and an outer frame which cradles the lower insert and presents four upward spike receptacles for the bass/midrange module. The inner plinth is wood, the outer MDF. This combines two different materials for resonance dissipation and effective decoupling from the floor. It ain’t voodoo. Diverse material combinations are popular all across speaker design and here applied to a plinth. The aluminum standoffs for the upper module follow the same rationale. The System F plinth incidentally incorporates some deliberate play. Should you detect a bit of give—which could be counter-intuitive after adjusting eight spikes per channel at first—that’s intended. Granted, you’ll have to shake the speakers quite hard before anything deigns to move.
The second ‘system ingredient’ is the bass/midrange module. It includes the retrograde TOS unit and four inner chambers, two for the bandpass alignment (one reflex chamber, one pressure chamber), one for the mid/bass driver and one for the rear-firing flat driver. To minimize box talk, Ascendo employs fibrous plates of 16 - 22mm thickness and varying density – including variable density within the same plate. Herr Heinz divulged that their panels increase in density towards the glue joints of the edges. The chambers meanwhile are dimensioned such as to minimize  standing waves.
The third module is the treble unit. The primary reason here is time alignment—more on that anon—but further benefits include mechanical isolation from the other bands, particularly the lower bass. Many competitors think alike – Wilson Audio, Von Schweikert, Sonics by Joachim Gerhardt, Phio Audio.


2/ TOS: A room’s echoic behavior is measured as RT60 or the time it takes a signal to attenuate by 60dB. Sonic satisfaction depends not on the absolute brevity of this decay time alone. It also depends on how homogenously it occurs across the full audible band spectrally. A quite common imbalance has treble decays shorter by absorption versus how the lower bands behave. Then adjustments to the room acoustics would be called for.

With the Transducer-based Optimization of the Summed decay time, Ascendo has built in the option for dipole dispersion above 2.400Hz. Because the TOS unit fires backward, this increases the diffuse components of the upper octaves to counter typical trends for overdamped treble energies. All it requires is triggering a rocker switch and settling in for personal preference. I’ll tip my hand early by saying it’s not a world of difference.


3/ SASB: The outer paper cone covers not merely the midrange to 3.2kHz where the tweeter takes over. It joins forces with the hidden woofer all the way down to 90Hz. As a signature trend of Ascendo, the System F too employs bandpass loading for the lowest range. This is a Semi-symmetrical Bandpass—to explain one part of the acronym—and implies that the lower roll-off to 31Hz occurs at a shallower 18dB slope than the upper roll-off toward 90Hz which occurs far more steeply at 30dB/octave.


Incidentally, the hole in the baffle isn’t a port. Ascendo’s System F is a sealed alignment and both woofers operate within closed volumes. This loading offers superior impulse response to bass reflex systems but reduced voltage sensitivity. Herr Heinz stressed that the inner and outer woofers operate in unison with very similar mass/drive characteristics and resonant frequencies whilst their min/max impedance values are complementary. This is referred to as dynamic current damping for the outer driver (Stromdynamisch bedämpfter Außentreiber in German to arrive at the SA part of the acronym). Ascendo claims "exceptionally extended bass with high impulse fidelity and constant group delay". If true, that’s something anyone could live with.


4/ VTA: Just as the Schwabians view their SASB principle as essential to end up with a perfectly time-correct speaker, the crossover network must serve the same ideal. The most visible ingredient on the subject of time coherence is the physically adjustable tweeter module offset.


The involved principle is simple to explain: Tweeters respond faster to electrical impulses than mid/woofers and woofers. Since all frequencies should reach the ear synchronized and at once, the ‘early starter’ is made to run a longer distance by locating its driver farther back. This can also be achieved with slanted baffles but the advantage of Variable Time Alignment is obviously its adjustability.


Coincident time arrival of all frequencies at the ear isn’t merely a function of the loudspeaker of course. There’s also the listener’s position or more specifically, seating height and distance from the speaker. According to Herr Heinz, the latter parameter isn’t as critical with the System F.


The illustration at left visualizes the context. Practically speaking, you simply look up the floor/ear distance in a chart from the System F owner’s manual. The given value corresponds with a scale setting on the top of the bass module. That’s where the rear baffle of the tweeter module should end. Once it does, phase correction has been achieved. Easy.

5/ BACYC: This abbreviation stands for Balanced Cylinders Configuration. With the TOS unit deactivated, the dispersion geometry of the System F is cylindrical rather than spherical.


This causes a certain amount of vertical beaming (a possible asset for reduced ceiling and reflections) and spectral weighting because the horizontal off-axis response of the higher frequencies induces faster roll-off than the lower bands.

One could nonchalantly shrug that every speaker loses its lunch – er, treble in the off-axis fields. Ascendo simply adds that their speaker does so deliberately and precisely calculated to serve up better sound. Cited advantages include lesser disturbances from side-wall reflections whilst the BACYC configuration in general is said to render the speaker more immune to room-acoustic conditions.
       

Sonics: It’s possible that you sweat over setting up, measuring, precisely dialing in the tweeter module, throwing three discrete speaker cable runs at the amp while attempting to forget it all for two long weeks of break-in… then attack it with notebool and pen, throwing in a familiar CD to kick off the first serious session – and it’s game over in three bloody bars. That’s because it’s too divine to bother with geeky commentary on specific frequency bands. Lights out and up high with the volume instead!