   
|
|||||
 September 1, 2005
Ascendo System C5 Loudspeakers Ascendo’s speakers caught my eye the first time I reported on the High End show in Germany. No wonder -- with their thoroughly modern styling and glossy finishes, they stand out in any room.But while Ascendo’s speakers have a bold appearance, they certainly don’t fall into the camp of "looks but no substance." The company is steeped in expertise, producing not just loudspeakers but electronic-room-correction devices along with measuring software and equipment. The guys at Ascendo are tech-heads -- and hardcore audiophiles to boot. Therefore, their speakers’ appearance doesn’t overwhelm the main function: producing high-quality sound. Look beyond the fit’n’finish and you’ll find each Ascendo speaker -- from the flagship System M to the focus of this review, the System C5, Ascendo's least-expensive model -- jam-packed with technical innovation. Ascendo speakers appear to have an equal doses of looks and substance, precisely the reason why the two-way, bookshelf-sized C5 carries a price tag of $2500 USD per pair for the standard high-gloss lacquer finish. There’s much more to the C5 than meets the eye, however, and quite a lot to its sound that is sure to please the ear. Description The C5 is relatively compact, measuring 9"W x 13"H x 11.25"D, and it weighs 20 pounds. As with the more expensive Ascendo speakers, the build quality and finish are first-rate. The review pair came with a high-gloss black-lacquer finish that ideally shows Ascendo’s attention to detail. There are other color options available -- last time I was in Germany I saw the C5 in yellow, red, and blue -- as well higher-grade finishes, although when I spoke to folks at Ascendo recently, pricing for these optional finishes hadn’t been finalized. One of the design goals of Ascendo speakers is achieving time alignment, something the company places strong emphasis on but is a contentious issue in audiophile circles and at most speaker companies. In a nutshell, time alignment involves the arrival of sound from the individual drivers to the listener’s ears. This is accomplished through the mechanical positioning of each driver and work done in the crossover to ensure that the sound waves from each hit your ears at the same time. Why don’t all companies concern themselves with time alignment? Often the benefits of achieving time alignment come at the expense of other design factors, and speaker designers who don’t place credence in time alignment often put other priorities first. As with most anything in loudspeaker design, there’s no free lunch -- to achieve one thing you often have to forgo another. Proponents of time alignment, though, obviously feel that getting the drivers "in synch" is crucial.
Instead, the company chose a rather elegant, cost-effective solution to achieve their goal. The C5 is based around a coaxial driver from SEAS that buries a 1" soft-dome tweeter at the center of a 6.5" polypropylene woofer. The benefit of a coaxial design is that the "acoustic centers" of each driver are, by default, lined up, so there’s no need to have an elaborate adjustment system or a stepped cabinet as you would with separate drive units. As well, with a coaxial driver, the alignment is not just achieved at one point in space as it is with a multi-driver array. Because the tweeter is buried smack-dab in the center of the woofer, the alignment occurs at all points surrounding the driver. Why doesn’t every speaker company use coaxial drivers in time-aligned designs? Some do, but, again, there’s no free lunch. Coaxial drivers have their benefits, but you also have the drawback of having the tweeter’s output interacting with the woofer cone that’s surrounding the tweeter. The C5’s crossover, which is implemented at 2.5kHz, includes what Ascendo calls a "constant voltage kernel" -- something also found on their more expensive speakers. Jürgen Scheuring, one of the principals and designers at Ascendo, explained it to me like this: Around the crossover frequency the roll-off between each driver is first order -- in other words, 6dB per octave; however, farther away from the crossover point the "constant voltage kernel" provides a steeper slope to shelve off the drivers’ response more rapidly. The purpose of this rapid roll-off is to overcome one of the deficiencies I mentioned that is inherent in time-aligned first-order designs: the rather shallow slope of a first-order crossover necessary for time alignment creates a broad overlap between drivers, meaning both the tweeter and the woofer operate far beyond the crossover point. For the woofer, this means running higher in frequency than is desirable, and for the tweeter, having to operate far lower in frequency than is good for it. The "constant voltage kernel" is Ascendo’s way of having their cake and eating it, too. When you flip the C5 around you’ll see a large port in the bottom corner of the backside, a single set of high-quality binding posts, and a two-position toggle switch that alters the speaker’s frequency response to help with room-placement options. Audiophiles often eschew these types of switches, but they can be useful, particularly for a versatile speaker like this one. The switch can be set to VD-H or VD-N (I haven’t figured out what either stands for yet). The VD-N setting is for positioning the speaker very close to the wall, perhaps on a bookshelf. Essentially, the highs are brought up (or the bass is brought down, depending on how you want to look at it) because the wall boundaries will help to reinforce the bass. The VD-H setting is for when you have the C5 farther out in the room, away from boundaries. With this setting the highs are brought down (or the bass is boosted). You want as much "heft" as you can get in the speakers’ bottom end because the walls won’t be helping as much as when the speakers are closer to them. Ascendo rates the frequency response of the C5 from 38Hz to 25kHz, and they say that the impedance is about 6 ohms. The sensitivity is said to be 87.5dB/W/m. Ascendo recommends power amplifiers rated from 20W to 150W and also notes that the C5 is magnetically shielded, making it suitable for use near a TV. The C5 is a pretty expensive two-way speaker, but it’s well built. I do have two nits to pick, however. First, there’s no grille. Acoustically, the absence of one makes sense for serious listening; visually, though, a coaxial driver staring at you all the time is not the most attractive thing in the world. I’d at least like the option to cover the drivers up. Second, the warranty is only two years, whereas five years is the industry standard. System I put the C5s in the same system as the ACI Sapphire XL speakers I just reviewed in SoundStage! last month. A Theta Data Basic transport fed a Stello DA220 D/A converter and the output of that went to a Song Audio SA-1 preamplifier. The digital cable was an i2Digital X-60, while the analog interconnect between the DAC and preamp was Nordost Valkyrja. The amplifiers were Stello’s M200 monos (140Wpc into 8 ohms), and the speaker cables were Nordost Valkyrja, too. I set the C5s atop 24"-high Foundation stands, which proved the perfect height for my slightly lower-than-normal listening chair. Sound I wasn’t as impressed with the C5s right off the bat as I have been with some other speakers I’ve reviewed, mostly because of the way I do my initial listening after I set up new speakers. What I do at the beginning is just use them for background listening for a time, always listening way off-axis, far away from the sweet spot. This, though, isn’t how the C5s sound their best. Far off-axis the C5 sounds dull -- rolled off in the top end, in fact. No fiddling with the VD-H/VD-N switch would fix that. On-axis, though -- preferably sitting dead center between the two speakers, which should have enough toe-in so that they are firing straight at you -- the C5s have crazy-good ability to throw you right into the recording venue with hyper-precise imaging amidst an amazingly expansive soundstage. What I learned quite quickly is that the C5s aren’t a "put them on and walk around the room" kind of speaker. The C5s demand that you listen to them seriously if you want to get your $2500 worth. Tonally, as well, the C5 shows a much better balance in the center spot, with a tidy top end, a very present midrange, and a surprisingly fleshed-out bottom end. The C5s sound a tad dark, meaning the bass and midrange frequencies are accentuated more than the highs. This also means they’re not the epitome of frequency-response linearity such as, say, PSB’s Platinum M2. In short, the C5s aren’t what's considered a "flat" speaker. However, that subtly dark sound is in no way a bad thing for a speaker this small. For example, if you accentuate the highs, as some designers do, but leave the bass down, many small speakers end up sounding thin. When you slide the perspective down lower and pump the bass and mids somewhat, as with the C5, you end up with a much fuller-, grander-sounding small speaker, even if the bass below 50Hz is essentially MIA and the highs are reticent, even on-axis. What’s more, these smallish, coaxial-based speakers do something that I never thought they would: They play pretty loud! I’ve been torturing speakers with the hard-rock-laden soundtrack to the movie Lords of Dogtown [Geffen B000455602] -- mostly music from the likes of Nazareth, Sweet, Ted Nugent, and other ‘70s "rock gods." This is stuff that needs to be played at "11," and, much to my surprise, when I thought the C5s would keel over and die, or at least make some objectionable sounds, they held together quite well -- a little better, in fact, than the ACI Sapphire XLs, which had some trouble with super-high SPLs. No, the C5s aren’t going to rival speakers that are made more for PA use than for high fidelity, but they are speakers that can handle some abuse, and even sound good with it. But if you’re buying the C5s you’re not really going to buy them for listening to hard rock or playing at parties -- remember, these are bandwidth-limited by virtue of their size. They pretty much want you to be alone with them and sitting in the center to appreciate what they do. And what they do is have enough audiophile allure in their performance that people who are serious about finding a great two-way will want to check them out for the very special things they can do with more suitable recordings. Chesky just released a disc that, I must confess, I thought was going to be a disaster when I first saw it: The Persuasions Sing U2 [Chesky JD306]. Somehow, I just didn’t think this could work. But it’s not a disaster at all. In fact, far from it -- I like this group singing U2’s songs as much as I like the C5s. The Persuasions Sing U2 has that Chesky "extreme fidelity" thing going on -- minimalist-recording technique with strong attention to audiophile details resulting in extraordinarily accurate tonal balance, amazing detail and resolution, and natural soundstaging that, if you have your speakers set up well, is so holographic it’s spooky. The level of precision, the coherence, and the musical "focus" that I heard playing this disc over the C5s were uncanny. While only the engineer and performers will know for sure exactly where each singer was positioned, I’m certain that I can make a "beyond a reasonable doubt" guess based on how well the C5s can image and lay out a soundstage. Front to back, left to right, and even on the edges of the speakers themselves, the singers’ positioning is unmistakable. It’s not only unmistakable, it’s unwavering, it’s unnerving, it’s, well, unbelievable -- the best imaging I’ve ever heard in my room, and among the best I’ve ever heard, period. The singers’ voices, too, came across as weighty and robust with detail galore. The midrange is, as I said, pushed a little to the forward, not unlike that of a good number of speakers that bump this region to impart a little more presence, but, as I also said before, that’s not necessarily a bad thing. There’s no chestiness or bloat -- there’s just more detail and presence. And the highs, well, they’re a touch recessed -- just a bit, not unlike ACI’s Sapphire XL -- but this can make the C5s sound polite rather than aggressive, just like the XL. Overall, I really enjoyed the sound of the C5s. They’re voiced in an exceptionally pleasing manner that makes this small speaker sound quite large, and I was absolutely blown away by how well they could image and how coherent they sounded. However, there was one thing that needs to be mentioned, and criticized, particularly for a speaker this expensive. I found a slight "cupped-hand" coloration in the upper-midrange frequencies and higher -- hold your hands around the side of your mouth and speak, or perhaps sing, to get the idea. It’s not drastic, and it’s certainly not off-putting, but it’s there, and if I were to hazard to guess, I'd say it’s due to the woofer surrounding the tweeter. Comparison, contrasts, and, ultimately, cost Save for the lack of a grille, I have no complaints about the C5's build quality. It shows workmanship that can stand tall among the "best in class." The biggest hurdle that the C5 has to overcome is its price, no matter how well it’s built and how nicely it’s finished. The C5 is not necessarily overpriced, because, for example, the diminutive FS-688 from Focus Audio, which I also like, actually costs more ($3190 per pair these days) and I can’t necessarily say that the ‘688 is better than the C5 in any significant way. But, likewise, I can’t say that the C5 is necessarily better than the $2000-per-pair Paradigm Signature S2 and PSB Platinum M2, either. Nor can I say that the C5 is across-the-board better than the ACI Sapphire XLs that I just reviewed on SoundStage! and cost just $1500 per pair. This is what happens when you get into the upper reaches of "commonsense" two-way speaker design: it’s not a matter of what’s better and what’s worse; it’s that they’re different and each ends up being preferable based on what you like sonically and what you’re willing to pay. Price and performance don’t necessarily go hand in hand.
The S2, M2 and Sapphire XL all come closer to the "ideal" of flat frequency response, but I can’t say that they necessarily sound better or worse for that matter than the C5. The C5 is voiced a certain way, and I quite like it; I also like the other speakers, too, even if tonally they’re not the same. In short, if you want neutral frequency response, you’ll likely opt for one of those three; if that’s not that important for you and you just want something that sounds good, the choice won’t be as clear, obviously, and the C5 should definitely stay in the running. Likewise, if you like to be able to walk around the room and have your speakers sound more or less the same everywhere, the S2, M2, and XL all have better dispersion characteristics and certainly don’t change their sound as drastically far out of the sweet spot as the C5 does. However, seated in the center, the C5's tonal balance shapes up nicely and, most notably, the C5 casts a soundstage that represents the ultimate, or close to it, in stereo precision, placing the performers so distinctly in space it’s uncanny. None of the other three speakers, despite how well they image or maintain more constant balance throughout the room, can quite match the C5s there. Conclusion No doubt, the Ascendo System C5 is a pricey two-way speaker, but it has a distinct set of performance characteristics that, for some listeners, will outweigh the premium price tag. The C5’s weaknesses: it deviates from frequency-response neutrality in the ways I mentioned; it demands that you sit between the pair of them to hear them at their best; and there is that small bit of "cupped-hands" coloration as you move from the upper mids into the highs. The C5’s strengths: a very pleasant overall balance, even if it's not the pinnacle of frequency-response linearity; a high level of refinement; sufficient "weight" at the bottom end to allow you to get by with no subwoofer; a surprising ability to be cranked up, if not to "11" then pretty darn close to it; and, mostly, a focused, defined, unwavering presentation that translates into a hyper-precise view of the recording venue. The precision that the C5 achieves is more or less this speaker’s sonic hallmark and more than enough reason for an aficionado of two-way speakers to seek out this distinctive gem from Germany. …Doug Schneider Ascendo System C5 Loudspeakers Ascendo GmbH E-mail: mail@ascendo.de
|
|||||
|
But mechanical positioning of
the drivers so their "acoustic centers" are lined up isn’t as easy at it
may seem. The drivers’ position will vary depending on exactly where the listener is
sitting -- when it comes to time alignment, one size doesn’t necessarily fit all. So,
if you look at Ascendo’s higher-priced models, you’ll see "arms" and
"braces" used to make adjustments to the drivers’ positions to accommodate
various listening distances and heights. At the price of the C5, though, Ascendo
didn’t have the luxury to produce an elaborate cabinet or complex driver-mounting
scheme. 
