ATC SCM 20 ASL Classic

ATC SCM 20 ASL

• Booking in a pair of ATC loudspeakers for review is a bit like getting a regular eye test. You may think your eyes are still up to scratch, but it’s only when you’re presented with a perfect lens does true clarity emerge, and this is the audio equivalent of what ATC is famed for in the hifi industry.
• And here’s an example of that honesty – take Wunderhorse’s latest anthemic EP The Rope streamed at 24-bit/96kHz via Qobuz, and compare it to tracks off their debut Cub album from some three years earlier. Now on paper the former should present a much better audio experience, with the increased bit depth and sample rate. But no, the lowly 16-bit/44kHz album trounces it on the ATCs. Why? Because it’s simply a better recording, and that’s what these speakers reveal, regardless of what the ‘hi-res’ numbers say. And with the ATCs the gap between the two is made that much more obvious, with the later recording sounding flat and closed-in by comparison. Well as on tracks such as The Girl Behind the Glass and Morphine from Cub, instrument separation, imaging and timing are pin sharp, making for a much more exhilarating listening experience.
• It’s that studio sense of taking you closer to the recording, like few others which runs through the SCM20 ASL’s DNA. Shola Ama’s You Might Need Somebody from the same LP for example sounds syrupy smooth on most systems and that seems good enough, like the sonic equivalent of a luxurious hot chocolate on a soft sofa that you can just sink into – nice, but a bit snoozy. But with the ATCs in charge boy does this track come alive. Everything from the strings to the horns, backing vocals to the funky bassline riffs just stand out that bit more. This is a sunglasses off, everything out in the open performance, and the music sounds that much more arresting for it.
• In summary - It’s a shame I’m not minted, because if I was a pair of ATC SCM20 ASL or their passive brothers would be my go to standmount reference speakers of choice, especially for comparison purposes. Sure they’re less forgiving than some, and more controlled than others, but the flip side is that they’re also more rewarding than most. And while £6.5k buys you a lot of loudspeaker these days, if you want bigger boxes for your buck then look elsewhere, but if you’ve a modestly sized room and favour longterm ownership that’s all about accuracy, detail and being taken closer to the source then these are ideal. And let’s not forget you’re getting two tailored power amps as part of package, making the ATC’s standout from rivals.
• Read the full review (PDF)

ATC SCM 20 SL & SCM 20 ASL

• Both SCM20 monitors belong to the Classic series, in which they are the smallest representatives and the only designs with a closed enclosure. There are two more floor-standing versions of this model—also passive and active, formally belonging to the Tower series. This one, incidentally, is a technical copy of the Classic series—the differences between the respective models come down to a longer (taller) enclosure, which, however, does not mean an increase in internal volume. In practice, we are dealing with technically the same speakers—with or without stands.
• The active version is larger—the enclosures are 10 mm higher (this is how much they are extended from the bottom), 10 mm wider (which changes the proportions of the front to a more voluminous shape), and above all, 45 mm deeper. This is, of course, due to the fact that the SCM20ASL electronics, based on traditional Class AB amplification, take up quite a bit of space at the rear.
• SCM20SL - The first and most important conclusion from listening to the passive version is that we're dealing with a genuine, high-quality monitor speaker that, while reveals its professional provenance, doesn't flaunt it, winking at the audiophile.
• Let's start with the bass, because this is the frequency range where most listeners will find the first, completely obvious differences from what they're (probably) accustomed to on a daily basis. Let's be clear. The bass of the vast majority of similar-sized monitors using vented enclosures is quite obese compared to what the SCM20SL, as athletic as a personal trainer, offer. I realize that in reviews we sometimes use the term "bass was even, not boosted," etc.—also in reference to bookshelf speakers. However, this is most often a relative comparison of characteristics to the market average or, to put it another way, the "default reference level." I try to be cautious with such statements, but my colleagues' opinions don't always coincide with mine, and this is, to a certain extent, the normal state of affairs.
• Let's get back to the bass of the "20" speakers. On an absolute scale, compared to most speakers of similar dimensions, there's relatively little of it, and it doesn't extend very low. In reality, it ends somewhere below 50 Hz, which is certainly not an outstanding or even good result. To make this point more explicit, I'll mention the similarly priced Dynaudio Contour 20i monitors, which present a radically different approach to bass reproduction. It's much deeper and more abundant (especially in the mid- and lower-frequency range), yet incomparably less detailed, tight, and much less articulate. If the Contours are compared to a heavyweight wrestler, the ATCs resemble a competitive gymnast. Agility, clarity, lack of bulk, slowness, or any heaviness—these are the quintessence of bass quality, very difficult to achieve from a bass reflex system.
• Despite the somewhat narrow range of the speakers and their free-field placement, in my nearly 30-square-meter room, I didn't feel any "underweight" in the lower registers for the vast majority of the time—at least not as long as I played acoustic music performed by small ensembles, as well as electric jazz, fusion, and classic rock.
• ATC monitors focus on the "substance" and weight of the midrange and treble, as well as the dynamics of both, to create an "alternative," i.e., a much better version of sound with a high degree of fidelity in the broad sense. I was pleasantly surprised by how vibrantly, quickly, and uninhibitedly these small speakers with a large, and therefore not at all light, woofer reproduce transients, how well they handle high volumes (read: high SPLs), and how valiantly they resist compression.
• Impedance measurement (SCM20SL) Passive ATC loudspeakers are considered difficult to drive, but electrically this is a myth... The impedance module curve is a proverbial piece of cake for any amplifier. From 100 Hz upwards, the frequency response falls within a narrow range of 4.8 to 7 Ω, and the electrical phase angles are negligible. The nominal impedance value should be assumed to be 6 Ω.
• The tweeter certainly plays a significant role in saturating the sound with a wealth of detail. If my auditory memory doesn't deceive me, and I doubt it does, it presents a significantly higher level of refinement and precision than the larger, similarly priced SCM40 (with a standard tweeter and a lower-quality crossover). I rate the quality of the upper registers of the SCM20SL as very good, even in absolute terms.
• The mid-high range, critical for tonal fidelity, sounds natural, revealing a slight, physiological retraction of the presence region, thanks to which the sound of Stephane Grapelli's violin from the album "Flamingo" recorded with pianist Michel Petruciani retained 91728253 91728253 34 the appropriate amount of softness and naturalness, without shrillness. The sound of the acoustic guitars in "Fend Yourself" by The Pinapple Thief was fresh, saturated, rich in overtones.
• The SCM20SLs have no difficulty achieving record-breaking depth of field. The sound sources are solidly embedded in space and do not take the form of small, uniformly sized dots in space. They are solid bodies, corresponding well to the relative proportions of the instruments and vocals (assuming that was the engineer's intention).
• The SCM20SLs are not overly analytical speakers that would repel audiophiles with their rawness or uncompromising nature. Yes, the bass is very "fine" and doesn't generate the anomalies that are inherent in the "audiophile DNA"—therefore, you won't find any fatness, power, or even the lowest rumbles, which we get (usually in excess!) from many, often suboptimally tuned, bass-reflex speakers. However, there's an element of softness and warmth in this sound, which a properly composed set of high-quality electronics will certainly bring out from these speakers.
• SCM20ASL - The first listening tests, combined with the break-in of a new pair of active speakers, which I conducted in a large living room, revealed a distinct lightness of sound. On the one hand, there was a somewhat unexpected thinness of the low range (which is not at all typical for small speakers in these specific conditions and positioning), and on the other, an emphasis in the midrange, resulting in a less than comfortable tonal balance compared to my beloved Infinity Renaissance 80 speakers (which also have a sealed enclosure). A week-long burn-in (12 hours a day) didn't bring any dramatic change. It's worth noting, however, that during that time I used the economical Topping A90 preamplifier and also (directly) the variable outputs of the Accuphase DP-65V player. After that time, the speakers landed in the main listening room, where I could make direct comparisons with the SL version. My initial suspicions largely proved accurate. Initially, I used the latest Topping A900 preamplifier, which, however, turned out to be an inappropriate partner for the SCM20ASL, emphasizing precision and not providing the sound with the proper weight.
• At my request, the distributor supplied the company's SCA2 preamplifier (eight times more expensive than the A900). It probably didn't take me longer than 15 seconds to come to the conclusion that this combination would remain until the end of the test. This is the basis (mostly) for these ATC SCM20 speaker sets in passive and active versions observations, which doesn't mean that the company's preamplifier radically changed the appearance of the monitors. However, it made the sound slightly fuller, better balanced, weightier, and less dry. However, this doesn't change the fact that the SCM20ASL have a significantly different character than the passive version.
• IN OUR OPINION
  Both versions of the SCM20 monitors seem to be designed for different audiences—and I'm not referring here to purely practical onsiderations, as choosing an analog active speaker isn't necessarily the first choice of audiophiles. I believe they'll be more likely to choose a passive model, who, in addition to ensuring full compatibility with classic systems, also offer a richer and more musical sound with a better-extended top end and a more natural midrange.
• The assessment of the bass isn't as clear-cut. Both versions deliver excellent bass quality, emphasizing precision and definition, at the expense of volume and extension.
• The active model offers a potentially valuable ability to fine-tune the bass to individual listening conditions, but this will likely be appreciated primarily by listeners with challenging rooms and who are forced to place the speakers near corners. In adapted rooms, where speaker placement is more flexible, the passive SCM20SLs, whose bass is almost perfectly balanced, may once again have the advantage, especially when paired with a very good amplifier. I consider these monitors to be one of the best speaker systems I know of on the current market, priced at at least 25,000 PLN. The SCM20SLs' level of refinement surpasses the excellent, though perhaps overall more versatile, SCM40s.
• Read the full review in Polish (PDF)
  

ATC SCM 20 ASL (Active)

• Let’s not beat around the bush, this is not a warm or cossetting speaker. Listening to the fabulous The World Is What You Make It by Paul Brady on the ATC is a different experience to running the Node ICON with the resident Chord Electronics TToby power amp and Focal Kanta No1. That trio is punchy but there is a warmth and refinement to the sound that gives it a slightly lush quality. The ATC by contrast eschews lushness. What it takes with one hand it gives with the other though. All of a sudden, what feels like a slightly languid bit of mastering has an immediacy and sheer realism that takes you aback slightly.
• It becomes clear that the ATC is able to both extract detail and rationalise it in a way that makes even some decidedly talented rivals (Focal has a thoroughly proficient Pro team all of their own remember) feel a trifle toylike. It’s the ‘rationalise’ part of this that is the most impressive. The SCM20ASL doesn’t simply fling detail at you, it contextualises it in a way that gives greater sense and realism to the wider recording.
• This is a monitor. It monitors things and tells you what is wrong with them. If you play Language, Sex, Violence, Other? by The Stereophonics on the SCM20ASL it has no choice but to tell you it was mastered with the dynamic range of a Tickle Me Elmo and has some of the worst audible artifacts in any recording ever actually signed off for sale. The only way the ATC could do anything good with this recording is if it had been used to monitor it in the first place.
• As a friend of beautiful live recordings, this speaker completely picks me up with dynamic music. Then I sat late in the listening room as if electrified, listened to Peter Gabriel's "Secret World Live" and couldn't move – these recordings had such a force, so intense was the lecture of the ATC – goosebumps up to my sparse hair.
• Six months ago, I reviewed the PMC twenty5 23i Active and I came away seriously impressed; it represented a serious upgrade in performance and convenience to the passive version. At the same time, I noted that the asking price left it potentially vulnerable to competition. Well, this is the competition. Simple physics means that the ATC cannot hit as hard as the PMC and it’s markedly less forgiving but… when the ATC is doing what it does, I don’t really care. This takes all the things that iterations of the SCM20 have been doing for 35 years and makes them more accessible, more capable and more appealing. No, it’s not cheap but you can see where the money has gone and the combination of longevity and resale value means it has to be judged carefully in actual value terms. This is a formidable active speaker and the current Best in Class.
  

ATC SCM 20 ASL (Active)

• ATC have long been advocates of active loudspeakers – their SCM50ASL is possibly the most popular example at the serious end of the market and for good reason. I used to use the substantial SCM150A actives as a reference but I haven’t had an active two-way standmount at home, so when the SCM20ASL was launched an opportunity was grasped.
• The power amps in an active speaker are connected directly to each drive unit and therefore have considerably greater ability to control them. ATC SCM20ASL active speaker review https://the-ear.net Another advantage is that electronic crossovers allow the designer more freedom. For a start there is no need to second guess the nature of the amplification as is the case in passive speakers: the crossover’s characteristics don’t change with level as the power handling factor is not an issue. ATC includes an all-pass filter in its active crossovers, which allows for the phase response to be optimised through the crossover point, something that is very difficult to achieve with passive designs and rarely seen.
• With this loudspeaker, jumping liveliness and precision are the order of the day. A nice (also very quiet) example was the piece "The Light at the edge of the Worls" from the new John McLaughlin album Live at Montreaux. No loudspeaker currently on LowBeats managed to follow the virtuoso runs on the bass guitar with such bone-dry precision. The bass drum came powder-dry and deep and the strings on McLaughlin's guitar also had much clearer outlines than you usually get in hi-fi.
• If the impression now arises that the ATC is a Beckmesserian dissecter developed only for studio work, which makes individual parts out of beautiful music, I have to contradict immediately. With it, even in studio recordings, a kind of live feeling immediately sets in, which is unparalleled with its great liveliness and its great fine and coarse dynamics.
• the really first-class combination of the Octave V70 CA tube amplifier and the Dynaudio Contour 20 BE did not manage to keep up with this drive, this grip and this accuracy with every impulse. But more authentic? More hands-on? Heartier and more pleasurable? These points all go to the ATC. Here, the active technology, in which ideal power amplifier electronics have been perfectly matched to the drivers, has an advantage. Especially since with these tweeters and bass-midrange drivers...
• As a friend of beautiful live recordings, this speaker completely picks me up with dynamic music. Then I sat late in the listening room as if electrified, listened to Peter Gabriel's "Secret World Live" and couldn't move – these recordings had such a force, so intense was the lecture of the ATC – goosebumps up to my sparse hair.
• Many a music lover may be irritated by this striking openness and long for a little more warming melting in strings and voices as well as for more shimmering high-frequency resolution. The small ATC is not made for that. She is an animal: extremely lively, extremely clean in reproduction and downright greedy in the discovery of the finest details. An exceptional loudspeaker for all those who want to experience music authentically and directly.
  

ATC SCM 20 ASL (Active)

• ATC have long been advocates of active loudspeakers – their SCM50ASL is possibly the most popular example at the serious end of the market and for good reason. I used to use the substantial SCM150A actives as a reference but I haven’t had an active two-way standmount at home, so when the SCM20ASL was launched an opportunity was grasped.
• The power amps in an active speaker are connected directly to each drive unit and therefore have considerably greater ability to control them. ATC SCM20ASL active speaker review https://the-ear.net Another advantage is that electronic crossovers allow the designer more freedom. For a start there is no need to second guess the nature of the amplification as is the case in passive speakers: the crossover’s characteristics don’t change with level as the power handling factor is not an issue. ATC includes an all-pass filter in its active crossovers, which allows for the phase response to be optimised through the crossover point, something that is very difficult to achieve with passive designs and rarely seen.
• The SCM20ASL is a meaty loudspeaker whose height (45cm) is only slightly greater than its overall depth (41cm), and it weighs a persuasive 24kg (bend the knees). The driver complement is classic ATC: a six-inch Super Linear mid/bass allied to a one-inch S-Spec soft dome tweeter with dual suspension, both drivers made in house at the company’s Gloucestershire base.
• A lot of the weight comes from the amplification and electronics pack on the back of the SCM20ASL’s cabinet. This comprises two Class AB MOSFET amplifiers, providing 200W for the woofer and 50W for the tweeter. That should be sufficient for most domestic requirements and then some. 
• It’s the immediacy that makes these ATCs so engaging. The precision snare work on MYT’s Till Tomorrow is combined with studio effects, which undermine overall sound quality but makes the music no less exciting and fresh. Bill Frisell’s live cover of Shenandoah starts quietly before the band joins in with a swell that is rarely so well delivered. The active nature of the SCM20ASLs gives them dynamic range that passive speakers can only dream about. It also gives them control, and it’s this that makes good recordings come alive in the room and makes the sound so real.
• Conclusion:
  • I have to say that the SCM20ASLs have nailed it for me. These apparently simple and relatively compact loudspeakers get to the parts that few others do and make the music so appealing that doom scrolling is no longer a thing. They may not have DSP electronics offering all manner of tweaks but this is very much in their favour. The SCM20ASLs are an all analogue, linear power supplied musical truth conduit that will have you glued to your music for years to come.
  • I would go so far as to say that they are a cure for audiophilia nervosa: you’re no longer thinking about how to make the system better but just wondering which album to play next. Upgrades to the signal path are however always audible so those who want more will be able to continue the quest. The ATC SCM20ASL is a speaker for all but the most incurable of tweakers.
    

ATC SCM 20 ASL (Active)

• ATC’s speaker models tend to have long lives by general industry standards. The standard, passive SCM20 was first introduced back in 1990 and continues in production to this day.
• The SCM20ASL are chunky, medium-sized two-way standmounters. They stand 45cm tall, weigh a hefty 27kg each and give off a no-nonsense functional aura that we find hugely appealing.
• The SH25-76S tweeter is a twin suspension design that is designed to suppress mechanical rocking motion through its travel, so reducing distortion and improving resolution. Its chunky motor system is based around a large 60mm Neodymium ring magnet.
• Below 2.2 kHz, the signal passes to the long-running SB75-150SL mid/bass unit. This has an unusual diaphragm that combines a 75mm dome with a 15cm cone to ensure a wide operating range and uses one of the biggest magnets we’ve ever seen on a driver of this type. This drive unit alone weighs 8.4kg, which is more than many complete speakers do. The large 75mm voice coil and short coil/long magnetic gap configuration all go into making a drive unit capable of accepting high power inputs while generating low levels of distortion.
• We have the active versions here, so speaker sensitivity isn’t an issue. The SCM20ASL packs 250 watts of Class A/B power into each cabinet, split into a 200-watt amplifier driving the mid/bass and a 50-watt module for the tweeter.
• They are neutral while avoiding the sterility that many other products that aim for such a balance struggle with. The integration between the drive units is wonderfully seamless. The speaker’s character changes very little as we move away from the sweet spot, which suggests well-controlled dispersion characteristics from both drive units and a well-engineered active crossover.
• The SCM20ASL’s resolution of detail is astonishing. They pick up the low-level instrumental stands in Quincy Jones’s Back On The Block set effortlessly and manage to arrange that mass of information into an organic and convincing whole.
• Voices come through with outstanding clarity and naturalness, and when the recording includes the likes of Stevie Wonder, Ray Charles, Chaka Khan and Ella Fitzgerald, that’s a real treat. The speaker’s sense of control is absolute, where even complex tracks such as The Places You Find Love are delivered with unusual composure and calmness.
• They are agile too, and have a firm grip on rhythms, which gives these monitors the ability to convey the ebb and flow of musical momentum well, and when the music demands, deliver it with excitement and drive. These are not speakers that add flavour in an attempt to make the recording sound better than it is.
• They deliver whatever the original signal has, nothing less or more. ATC’s aim is honesty and transparency, and we think it has succeeded.
• What Hi-Fi? Verdict: ATC’s SCM20ASL is about as insightful and transparent a speaker as we’ve heard at this level. Be warned though, their honesty-first approach won’t suit all
  • Pros: +Astonishing clarity, control and resolution +Taut and articulate bass +Rock solid build
  • Cons: -Ruthless in exposing flaws in recordings and partnering components -Some may crave greater low-end weight and muscularity

ATC SCM 20 ASL (Active)

• And top-notch the ATCs definitely are. They may only claim bass down to around 55Hz, but that proves more than adequate for a huge range of music given the dynamics and definition on offer here, which are respectively massive and really sharp-focused.
• Play Lady Gaga’s Abracadabra from her Mayhem album and the speakers deliver a hard-charging, superbly weighted sound while keeping both the vocal and the multiple layers of the mix crystal clear, right from the opening percussion and bass.
• They sound big and fast, thumping the track along in perfect Europop style, and prove willing to be cranked hard to fill the room with music.
• With the immaculately recorded recent release of Mozart piano sonatas by Angela Hewitt, the ability of the speakers, when they’re set up with a slight toe-in, to create an entirely convincing image of the instrument, with both scale and finesse, is wonderful. That sense of the instrument in the room with you, and the walls of the listening space pushing out to represent the recorded ambience, is as impressive as the clarity of each note in the Ah! vous dirai-je, Maman variations
• ATC has been making active speakers for ages, but the SCM20ASLs couldn’t be better suited to the streamed music age. There’s an appealing purity to speakers such as these, connected to a network player via a relatively simple interconnect run. The look of the speakers may be classic, especially in those real-wood finishes, but this is in every way a very modern system solution.

ATC SCM 20 ASL (Active)

• Following up on his review of the passive SCM 20 SL back in January, Tarun Sharma - A British Audiophile - has reviewed the new active SCM20ASL on his You Tube channel.
  The review was overwhelmingly positive and the SCM 20 ASL has been graded as 'Outstanding': ATC SCM 20 ASL Review by A British Audiophile
• ATC have just launched the SCM 20 active stand mounts but without the uber fancy finishes of the 50th anniversary model they're a lot cheaper than the floor standing version as well despite having essentially the same parts
• the SB75-150SL midwoofer is one of the finest transducers in existence the 150 mm 6-in driver contributes to about 40% of the weight of this speaker i go into details about the underhung voice coil massive superlinear motor structure and decoupling central 3-in dome in my review of the passive SCM 20s so I won't repeat it here
• the SCM 20 ASLs are the cheapest active speakers to feature ATC's S-spec 25mm 1-in tweeter: the same SH25-76S driver is used right up to the range topping SCM 300 ASL T's that sell for £52,000 a pair
• there is the ability to adjust the bass from - 2 to + 3 dB and alter the input sensitivity each driver has its own dedicated amplifier with a 200 W MOSFET class AB amp driving the midwoofer and a 50W one for the tweeter; the crossover is at 2,200 hertz with a second order Linquitz Riley slope
• Sound quality: what I loved about the passive ATC SCM 20s that I reviewed at the beginning of this year was the mid-range presentation: the combination of detail body and texture is the best that I've heard up till now
• the active versions of the SCM 20s are maybe just a tiny bit cleaner in the mids -it's hard to say without having them both here at the same time because it's a close call. but what the self-powered versions definitely have going for them is a more dynamic tighter bass and airier top end. it's nice that you can fine-tune the bass to suit your tastes and room as well
• the fact that sealed boxes roll off more slowly than ported designs, all help to get more bass extension than the stated 55 Hz at - 6dB: I suspect the SCM 20s were digging down to the mid-40s in my room
• the passive version of the SCM 20s retail for 4K and that leaves you 2 and a half K to spend on a power amp, not an integrated. there are some power amps that may get you close such as ATC's own P1 power amp that's similar to the one used in the Actives to power the midwoofer
• I doubt you'll get the same fidelity and control through any passive combination I can think of for 6 grand. that's the benefit of a proper active solution there's just significantly less loss through the crossover
• if you want to hear clarity sound stage and imaging get them well away from room boundaries, as you can see behind me. I wound up with a fairly conventional position with regards to towin the speakers pointing just wide of my shoulders
• in terms of grip control and overall fidelity, especially in the mid-range, I don't think you're going to get there for 6 1/2 grand for speakers and amplification, even with the Synergy god smiling, and that's why the ATC SCM 20 ASLs get an "outstanding" from this channel