ATC SCM40A Speakers Review

This year has been a good year so far for me in the world of HiFi attending my first HiFi show in Bristol in just over 3 years since the pandemic. It was refreshing to see and hear exhibitors showing off all things HiFi, with some great British brands showcasing what they have to offer. It just so happens that one of the best sounding rooms of the show was from the Acoustic Transducer Company or as everyone else knows them ATC who were demonstrating the incredible SCM50A speakers partnered with the ATC CDA2 CD /DAC preamplifier and Technics turntable, this was one of the most enjoyable and natural sounding rooms of the whole show and when I got offered the chance to review a pair of their speakers I literally jumped at the chance. Having reviewed the excellent SCM19A speakers previously I was offered the bigger SCM40A speakers which are a three way tri-amplified beast that look as good as they sound.




With five decades of experience in the world of speakers they are renowned for the quality of their drive units and in particular in the PRO Audio world where they are used by some of the biggest names in the industry like Sony Music and Telarc. Most importantly all of their components are designed and made in house which makes production an easier process as you are not relying on third party components to manufacture. Active speakers has always been a bit of shy point when it comes to HiFi but in fact it makes a lot of sense as the speakers amplifiers are designed and built by ATC to get the best out of there own speakers plus you don’t have the box count and decisions on what amps to choose that usually comes when powering a three way design like the SCM40’s, instead you get carefully matched active crossovers with amplifiers built to get the best from each of the three drive units in the speaker enclosures.

Build quality and features

As expected the build quality of the SCM40A’s is exceptional with beautifully curved cabinets which also help to negate any internal standing waves and with heavily braced cabinets mean they weigh in at a hefty 36Kg per speaker therefore they arrived in there very own flight cases, although on wheels they proved extremely challenging when trying to get them into my humble abode. The amplification section of the speakers are made up of 242 watt class A/B amplifiers with 32watts dedicated to the tweeter, 60watts for the midrange unit and with the bass driver getting a healthy 150watts to drive it, so each drive unit has its very own mono block driving them, consider the cost of buying 3 x mono blocks separately to power each speaker and you soon realise what a bargain these speakers actually are.

The newly designed ATC 25mm dual suspension soft dome tweeter is housed in a precision alloy wave guide, midrange is taken care of by the ATC designed and built 75mm soft dome midrange driver which looks the business and defines the look of their speakers, then you have the 164mm bass unit with an oversized dust cap completing the package, all of the drivers have massively optimised magnet assemblies which mean they can withstand some serious abuse from the volume dial without even breaking a sweat. On the rear of the cabinets is the amplifier plate which has an XLR connection, power socket and an on off power button, nice and simple but all that is required to get them up and running.

Connecting up is a breeze and because my Cyrus amplifier does not have balanced outputs I am using a male XLR adapter plug connected with Chord Company RCA cables to the outputs on my 82 DAC Integrated amplifier, the Cyrus is a great performer and works well acting as the preamplifier. Source equipment is taken care of by the Cyrus Audio CD8SE player and my Bluesound NODE 2i streamer to play Quobuz and high-res music stored on my NAS drives, the Chord Electronics Hugo 2 is slotted in between the streamer and amplifier for DAC duties.

Half way through this review I recieved the ATC CDA2 CD player/preamplifier and DAC so I am now also running them fully balanced with XLR cables directly from the CDA2 to the speakers.






Performance and Sound Quality

As always music is the best part of any review and fortunately I have been re-exploring my CD collection since the ATC SCM40s arrived and it is quite addictive when you start listening to albums that you thought you knew and the ATCs breathe new life into them. An album that I know well is Boris Blank’s 2014 release of Electrified on the Polydor label, this version is the 2 CD with DVD which has been getting many hours of airing since the speakers arrived. Both discs are just a stunning listen and I first heard this album on a pair on Martin Logan Neolith electrostatic speakers which was quite an experience and one that I will not forget, so when I uncovered it again I got quite excited to give the CD a spin, the bass especially was a visceral experience on the Martin Logan’s so I know what could be achieved when possible. Track one as per the album name is Electrified and from the very start the SCM40’s deliver some stunning bass which is as tight and forceful as I remember but tuneful with no overhang at all, it just energises the room with waves of bass and in such a controlled fashion, they can play very loud indeed and with startling clarity leaving you in awe at what power and the capability of what a fully active speaker system can do, my room is not massive but it is certainly not small and to be honest there would be no need for a subwoofer with the amount and quality of bass on offer, the sealed design of the ATC’s also help massively here as everything is kept well under control. I have not even started to describe the midrange which is very special thanks to the beautiful 75mm soft dome driver, it has an uncanny way of throwing the sound out in a manner that can only be described as holographic, the top end is sparkly without sounding at all fatiguing, the speakers imaging is also first class with a very wide stereoscopic three dimensional image being portrayed in front of you, sound appears from all angles in the room, very impressive and most importantly enjoyable. The transition of frequencies between drivers is seamless working harmoniously and this is more apparent or should I say less with track six Big Beans which is a rollercoaster of a mix and so fast paced but the SCM40’s handle this track with aplomb. CD two is a much more relaxed affair compared to the first disc but still as enjoyable, track one A Touch of Magic is a haunting melody with superb imaging and with such a wide soundstage produced by the ATC’s, it’s one of the best I have heard in HiFi and you would swear that you have surround speakers hooked up such is the wrap around affect that they create, some of the best imaging I have heard from any system.




On to something a little more laid back and that is with the superb voice and music from Diana Krall with the album Girl In The Other Room via Quobuz in high resolution 24bit 96kHz, this is a wonderful sounding album and perfect to test out the SCM40A’s as I have listened to the hyper fast electronic music from Boris Blank and they handled this type of music brilliantly but vocals and in particular individual instruments are the real test for any speaker and how they reproduce them. 

Track three Temptation is one of my favourite from this album and her voice is silky smooth sounding with the soft dome midrange driver showing its brilliance in how it can perfectly replicate her tone and voice, not just vocals that is impressive but the double bass and drums and in particular how the drum brush is swishing against the drum skin making the distinct sound and then the electric guitar notes are crisp all within the sultry jazz club sound stage, it makes for a beautiful performance, piano notes are also so well defined and no more so than in track four Almost Blue with the lower piano notes having real attack in the lower bass levels. Track eight Black Crow has some wonderful percussion and shows how well the ATCs reproduce them, drums have real snap and that double bass sounds so good, since introducing the CDA2 the bass has taken on a new meaning and immediacy which was good with my Cyrus Audio equipment but the SCM40’s really have come alive since adding the CDA2 player, showing the excellent synergy and how good ATC’s R&D and audio engineers are at developing their own equipment, the perfect combination.




For my last album I am spinning the brilliant and unforgettable sound of The Dave Brubeck Quartet on the Columbia label with the album Time Out Take Five on CD. Track three is a classic and is instantly recognisable by the piano rift which continues more or less the whole 5:24 of this track and became a massive hit for this jazz quartet back in the day and still is and playing through the ATC CDA2 and SCM40A’s the music comes alive with real impact for each of the notes that is played, the saxophone stands out and once again the imaging that these speakers create is simply superb with the quartet, each of them having there own space within the soundstage and commanding each of there performances, but the real magic happens when the drums kick in and when I say kick in they certainly do, the thwack of the snare drum and kick drum can be felt in your chest such is the impact, I have only ever had one other speaker system perform this so well and it cost at least 4 to 5 times the price of the ATC’s there is not a hint of distortion either in any of this performance when the volume is cranked right up instead it is just tuneful and well rounded, close your eyes and the speaker locations simply disappear and notes just seem to hang out in the air, Dave Brubeck playing piano is hypnotic and captivating by his performance, this truly is a masterpiece of music that I never tire of hearing and the big ATC’s play this to near perfection, the midrange on this speaker is phenomenal and a lot of what makes this speaker so good but all three drivers have been perfectly matched with the correct amplification to give you the best performance and then you have the CDA2 which is a serious bit of kit and does everything so right and as a complete package gives you the ultimate fidelity.



Conclusions and final thoughts

I have heard and owned a lot of different speakers over the years and reviewed a fair few now but actives have never really been given the attention they deserve, well they certainly have my attention now and I am utterly convinced by what is capable of a fully active system such as the SCM40A’s with the partnering CDA2 preamplifier, this combination does everything so right and plays all types of music so well that I would love to own them and have thoroughly enjoyed my time with them, for the money these speakers represent astonishing value for money and what you can’t put a price on is the enjoyment that they bring which they deliver in spades.

The Speaker Shack awards the ATC SCM40A’s with an Editors Choice award which was partnered with the brilliant ATC CDA2 CD DAC preampifier.

Price at time of review £7,750 for the SCM40A’s and CDA2 £3,100.


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