ATC

SCM40A

Active Floorstanding Loudspeakers

£7,750

If you think about it, active loudspeakers should be more prevalent. Those of us with a love of hi-fi separates tend to spend considerable time and money searching for the ideal match between loudspeakers and amplifiers. This quest for synergy then extends to cables, isolation, coupling and decoupling experiments and so on, too…

However, with speakers like ATC's SCM40A, this time-consuming and oft-frustrating step is rendered redundant – as its 36kg cabinet comes fitted with a dedicated 242W Class AB triamp arrangement, plus an active crossover. This configuration consists of a 150W module for the bass driver, a 60W unit that drives the midrange, and a 32W amp for the tweeter – all designed and built in-house. A pair of MOSFET transistors per channel add up to four identical output stages, fed by three separate secondary power supplies to scale the power according to the frequency band and driver demands.

The active crossovers are fourth-order Linkwitz-Riley designs with additional all-pass filters at the two crossover points, connected directly to the drive units at line level. The result of this method should be more accurate handling of the crossover points and improved control, thanks to the direct connection between the power amplifier and the drive unit.

DRIVE TIME

ATC has another significant differentiator to many similarly-sized loudspeaker manufacturers up its sleeve, in that it makes all its own drivers. Interestingly, the company still uses the original coil winder it had made when the British firm started fifty years ago – ATC stands for Acoustic Transducer Company, after all. This gives total control over every aspect of production, rather than relying on original equipment manufacturers to do the design or production work.

The SCM40A features ATC's trademark 75mm soft-dome midrange unit that can trace its lineage back to 1976, alongside a 25mm soft dome tweeter with precision alloy wave guide and a 164mm short coil bass driver with a massive central dust cap. Having visited the factory, I have seen first-hand the degree of care and attention given not only to the hand-built construction of these drivers but also great pride over the level of quality assurance performed. This gives confidence that everything is of the highest standard, which is extremely important given that the same company produces top-notch equipment for the pro audio market and can be seen in many recording studios worldwide.

The SCM40A is a substantial loudspeaker standing 980mm and 370mm wide, but the lovely curvature of its sealed cabinets offers some aesthetic relief. Available in cherry and black ash finishes, it is constructed of sturdy 18mm braced MDF, with the side panels consisting of a laminate of three individual layers of 6mm MDF to provide greater stiffness and damping. As well as being easier on the eye, the curved sides minimise parallel surfaces, helping to mitigate internal standing waves.

While this 36kg speaker looks totally in proportion and has a classy, no-nonsense appearance, particularly in the black ash pair supplied for review, some prospective buyers might not approve of the steel mesh magnetic grille. Although I like its studio-chic and practically unhindered airflow, I can imagine others seeking a more domesticated aesthetic for their loudspeakers.

With my Gryphon Essence preamplifier at the ready, it was a simple task to hook the SCM40A up via Tellurium Q XLR cables, with the review pair of SCM40As fed AC mains power. Being an infinite baffle design, this loudspeaker is somewhat ambivalent about positioning choices. That said, having my review pair slightly toed in at just over two metres apart worked exceptionally well in my listening room.

THE LISTENING

The SCM40A took no time to impress upon me that it's the kind of speaker that's ready to rock. The onboard power amps provide plenty of grunt with a healthy 19V rms over XLR on tap, which meant that lots of air was soon moving around my listening room. Yet this speaker was still able to leave its lab coat in the studio, and slide into a pair of slippers, acoustically speaking. By this, I mean that despite ATC being very much a pro audio brand, this speaker has plenty of audiophile hi-fi appeal – it's less clinical than many pro speakers whilst remaining highly insightful and punchy.

Another pro audio attribute that this ATC shares with its siblings is that it's largely genre-agnostic. In other words, no matter what type of music you play, it still reproduces all the acoustic fundamentals just as they should be. Undoubtedly a great deal of this skill lies with the articulate treble and upper midband, which comes across as perfectly voiced rather than dry and analytical. A case in point is the way this speaker reproduced the violins in Max Richter's Recomposed Four Seasons recording on Deutsche Grammophon. This exalted chordophone can be poorly treated by aggressive tweeters, making them shrill and brittle. However, the SCM40A kept the high-ranging strings sounding melodic and vital, with realistic leading edges and decay full of harmonic content.

While this speaker's tweeter is undoubtedly an able performer for the price, it isn't quite the last word in high-frequency units – as I heard a slight lack of atmosphere around the notes compared to when listening to Audiovector's AMT driver, for example. All the same, the SCM40A's drive units all work seamlessly together, which is a clever trick to pull off for a largish three-way design such as this. The lower frequencies arrive at your ears at the same time as the mids and top, so that when listened to as a whole, you're rewarded with a wonderfully tight, powerful, engaging and emotive presentation. I suspect that the well-braced cabinet's sealed design helps here, too.

Meanwhile, turning to Stravinsky's The Rite of Spring; Mavra (BMC) performed by the Junge Deutsche Philharmonie / Göteborgs Symfoniker under the baton of Péter Eötvös, the SCM40A proved that it can impart significant dynamic contrasts with unexpected agility. Whether my review pair was joyously banging out dramatic crescendos or whispering flute trills, the scale and fluidity of the music remained a thrill throughout my time spent with them.

Tonally speaking, I like my loudspeakers to be a little on the analytical side of things – likely the result of spending so much of my time in and out of recording studios with various bands. The SCM40A has a slightly dry monitor-ish timbre that you may or may not appreciate. That said, it does make it adept at remaining sure-footed through complicated, even chaotic, pieces of music such as The Mars Volta's 2003 opus Deloused in the Comatorium. While it could make sense of the Texan experimentalist's tunes, this speaker did so without giving the listener a softer-filtered version. Instead, the ATC created a more precise musical vista thanks to its impressive talent for timing and resolution. However, to get the best out of this big box, you really need to turn the volume up – it's not the world's greatest low-level listen.

While unravelling a piece of music's harmonic content can become addictive through a talented loudspeaker such as this, experiencing the drama of music should also be enjoyable. Thankfully, the SCM40A can be easily tempted into flare-flapping territory. Dropping the needle on Billie Eilish's You Should See Me In A Crown, and the advantage of this sizeable active speaker became grin-inducingly apparent, as waves of subsonic fun thumped and growled through my listening space. Such seismic activity made me feel like a kid discovering sweets for the first time, but I couldn't help but also be impressed by the amount of control that this speaker displayed. Not only was I getting a healthy punch in my chest, but there was no sloppy overhang or blurring.

THE VERDICT

Talented, dynamic, and fun, with a soundstage wide and deep enough for you to forget about the cabinets standing in your room, ATC's SCM40A makes a great case for itself. ATC's pro-audio DNA shines through, with a musical performance offering fresh insight and impact to pieces you thought you already knew inside out. This speaker presents orchestral music with scale and finesse, yet you can turn things up to hooligan levels without fear of the drivers letting go and musically losing control.

This is a superb active loudspeaker package, especially when you remember that you just need to add a good quality preamp and source to have a full system. We loved its passive sibling, but the active version is on another level and is cracking value for money too. So if you're looking for a largish floorstander with great power and composure, hear this big banger at your nearest ATC dealer.

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