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ATC SCM40A Active

The ATC Active 40 speakers stand out in many ways. For starters, they are 10 years old - a model lasting this long is almost unheard of in the everchanging hi-fi world. They are built, in their entirety, in ATC’s Gloucestershire factory and cabinet workshop and they weigh in at hefty 36kg each - and it’s fair to say, they have presence, both in sound quality and physicality. While they’re no spring chickens, what better example is there to mark ATC’s 50th anniversary of audio engineering prowess?

My introduction to ATC was odd. Many years ago, while working in a publishing company, I had an Australian boss who was best known for his ‘frankness’ of phraseology. He’d collar me with something along the lines of “strewth, Blackie, those new speakers Wombat has made are just brilliant” - although usually somewhat more colourfully expressed… 

‘Wombat’ turned out to be Billy Woodman, an Australian cobber and the founder of ATC speakers, who sadly passed away a couple of years ago. The company was started in 1974, and in the subsequent 50 years it has built a rock-solid reputation both in the professional market and with hi-fi aficionados. 

The SCM40A Active, launched back in 2015, was based on a passive three-way speaker from a couple of years earlier. The fact that it hasn’t been changed or even fiddled with in the intervening years is testament to its quality and engineering integrity - doubtless ATC will do something with the SCM40A Active at some point, an upgrade of some sort, but there is no screaming urgency. Right now, it’s mightily fine just as it is. 

It's worth a brief pause to outline the rationale of active speakers. In effect, they do away with the need for a separate power amplifier in your system because they already have one built in. The theory (and the fact, as far as the Active 40s are concerned) is that the shorter signal path results in a purer, less adulterated sound. So, although these speakers are considerable in price, you’re saving on the need for separate power amplification.

The SCM40A (the model number represents the internal cabinet volume in litres) features drivers and amplifiers designed and built wholly by ATC - the drivers are individually powered by a proprietary ATC tri-amplifier pack. The satin-finish laminated wood cabinet is curved for acoustic benefits, as well as doing an admirable job for the aesthetics as well. The speakers can be supplied with grilles to cover the drivers - and while the naked drivers look great, I can see why some may prefer to have them covered. ATC says that the difference in performance with or without grilles is negligible.

The rear panel is where you’ll notice the differences when compared with a passive speaker. Here you’ll find a standard mains power socket, an on/off button, a single input socket for a balanced XLR cable and a huge heat dissipation grille (the speakers certainly do get warm), and that’s about it. It’s plain and simple - all the ATC-designed electronics and speaker tech remains inside, out of sight. 

Sound quality

This encounter with the SCM40A Active represents my first meaningful encounter with active speakers, and, in addition, I had until now only a passing ‘hi-fi show listening-room’ relationship with ATC.

To say I am blown away is an understatement. The detailed soundstaging, and moreover the pleasure these speakers generate, is revelatory in more ways than one. The well-worn phrase of “the speakers disappear” comes across loud and true - at times the soundstage extends well beyond the cabinets.

The integration of the three drivers is sonically seamless, with the range from some really low-end thrust through to the trilling of a piccolo perfectly executed - whatever the music and whatever the volume. And these ATCs can deliver stupendous volume - I enjoyed ample oomph when hovering around 65 percent output showing on the preamp.

Get the positioning right and the bass response has to be experienced to be believed. Tight and accurate, for sure - but wow, the depth. It puts me in mind of a live concert atmosphere in my own room. On bass-heavy albums such as Beyoncé’s Cowboy Carter there’s masses of low-end force, yet it doesn’t dominate or detract - and when subtlety is called for (Miles Davis’ Sketches of Spain, for instance) the rendition is impeccably controlled.

There is a musical quality to the Active 40s that makes sitting in your seat hard to do - you’ll feel the urge to get up and shake your thang. Attractive, welcoming, pure, accurate but never sterile: compelling listening starts here…

Living with

At just over a metre tall with the floorspikes in place, the SCM40A Actives exude dependability and strength in a cloak of understated elegance. They are impressive and imposing - in a small space, they could be too dominating. I’m fortunate to have a 20m² room and they sit flawlessly at home in there. 

The optimum positioning takes some figuring out, and while ATC says they are ‘room-friendly’ I find them sensitive to placement. Too close to a corner and/or back wall, for example, and the bass splurges out everywhere. However, the remedy is simple: move the speakers literally a few centimetres further into the room and everything becomes tighter, more organised and better controlled.

I use two different system combinations, with equally impressive results. Firstly, the Cyrus Stream XR and its excellent BluOS streaming system. This creates an extremely capable combination with amplification taken care of by the speakers - so nothing else is needed. 

It is worth bearing in mind that a stripped-back system such as this needs the streaming unit to have a volume control. The speakers have an on/off button and that’s it, so a source without a volume control wouldn’t be suitable.

With the Cyrus XR Stream all that is required is a couple of adapters to connect the balanced cables to coax, and off it goes. A superb, straightforward system.

Next up I try the brand-new NAD M66 preamp - and it’s a match made in heaven in terms of sound quality, as well as making for a far more versatile system thanks to the plethora of inputs for external sources in addition to its top-notch streaming system credentials.

This forceful preamp has balanced speaker XLR outputs, so there is no need for any adapters. Everything ties in beautifully, whatever the source – radio, hi-res streaming or CD, all without a hint of frustration or fuss.

The SCM40A Active and NAD M66, to my mind you, constitute an outstanding system in every respect. Yes, at around £12,000 it’s pricey - but think of the dynamic joy that this combo delivers and you can start the process of justification.

Bear in mind that if you have a wooden floor, some sort of protective cover to place under each of the spikes is in order - particularly if you are moving the speakers around to find the best position. Be aware, because of the sheer weight of the speakers, your floor may otherwise end up looking like it has an infestation of wood borer.


Rarely have I had such an urge as to get up at 7.30am and immediately crank up the volume to be inspired, at the max possible volume, by Ode to Joy in Beethoven’s final movement of his Ninth Symphony. But I have neighbours to consider… 

Such is the alluring quality of the SCM40A Actives, that this is a component I really can’t get enough of. There is nothing you can throw at them, in terms of musical style or quality of recording, that makes them get tetchy or turn in anything other than a commanding performance. Making a return to my long-standing reference passive speakers has just become a little more difficult… 

The SCM40A is not a one-night stand or even a casual acquaintance. It requires compassionate handling, a decent space to flex its muscles, and careful positioning. If I were handing over my £7750 I’d have my local ATC dealer around (there’s a fair selection of them across the country) to install the speakers in the optimal position - and not least because, at 36kg each, they take some manoeuvring.

Listening notes

Mark Knopler Two Pairs of Hands

One of the many ATC advocates, and one of our most beloved guitarists, chugs along with consummate ease - from the very first note, there is no doubt who’s playing on this new album One Deep River. A superb, elegant recording, brimming with masterful confidence, and with perfectly-weighted bass keeping the rhythm memorable.

Brian Eno Sushi

Not sure I’d want to listen to this with the lights out. Terrifying soundscapes made all the more exciting and dramatic thanks to the stereo imaging and depth from the ATCs. A 16-minute track from a three-hour live concert in 1998 with Brian Eno, Holger Czukay and J Peter Schwalm, it’s tricky to classify this as music - it is a challenging experience that needs quality kit such as this to bring its massive force to the fore.

Gemma Sherry Gazing at Stars

The album Gazing at Stars is a five-quid bargain on Bandcamp, and this barebones recording is atmospheric in the extreme. Sherry’s awesomely clear vocal style, occasional bass making its subtle appearance and the hint of brushes on drums combine to create a recording that’s as smooth as you like.

What the press say

Why you should buy it

You have the space to do them justice, and you want a quality of build and listening pleasure that are equally impressive. The SCM40A Actives are timeless in appearance and significant in sonic gratification - the more you listen, the more they reveal and the more you will love them.

Video review

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