ATC SCM 5.1 Review – Brit speakers get a depth charge

Ed Selley puts ATC’s new subwoofer to work in a multichannel package from its SCM series. Read our ATC SCM 5.1 Review.

Tucked away in the west of England, ATC Loud speakers has spent several decades doing things in its own way with little interest in what rivals happen to be up to. The company builds everything in house, crafting its cabinets and even winding its own voice coils. Attention to detail is one of its strengths.

ATC SCM 5.1 Review
The C3C centre doubles up on ATC’s 6in midbass driver

Its in-house engineering also extends to the construction of amplifiers, used both in standalone products (integrated and powers amplifiers) and an extensive range of active speakers. This combination of skills means that ATC is one predominantly hi-fi-oriented brand that’s not afraid to get down and dirty and make a subwoofer. Just one, mind.

The duty of providing affordable sub-bass for its SCM (conventional cabinet) and HTS (on-wall) speakers – the rest of the ATC stable is two-channel, with no centre channel option – has historically fallen to its C1 subwoofer, but the brand felt there was room for improvement so has replaced it with the C1 Mk2.

The redeployment of the original name is indicative that not everything has changed. Indeed, at first glance, the differences between the two models seem fairly small. The cabinet and driver remain the same; a sealed design housing a downward-firing 12in doped paper woofer that is hand-built in the same way as ATC’s smaller drive units.

The amp specification also appears the same as it was before. ATC has little interest in the world of Class D, so the C1 Mk2 uses a 200W Class A/B amplifier, and has a prominent heat sink on the rear panel to prove it. But this is an all-new amp design intended to take performance up a notch. The power supply has also been upgraded, to ensure there is more current available for dynamic moments, and there are major changes in the preamp section; low-pass filter circuits and phase control have been reworked ‘to facilitate the best possible integration with partnering speakers from ATC and other manufacturers,’ and overload protection has been improved to provide ‘greater control at full output.’

In a world where subwoofers have apps of their own and various EQ features, the C1 Mk2 comes across as a little old-school (particularly in our cherry wood finish) but it feels immensely solid. The only visible indicator that it’s fired up is the tiny power/overload light within the metal logo plate on the front panel.

The back plate also feels a bit minimal, but there are frequency and level controls and the connections cater to daisy-chaining to another woofer rather than needing multiple outputs on your AVR.

In terms of specification claims, ATC suggests the C1 Mk2 can reach down to around 25Hz (-6dB). That’s not best-in-class, but with LFE it’s not how much you have, it’s what you do with it…


Shopping at the 7-Eleven

Partnering the C1 Mk2 in this 5.1 array is a speaker selection culled from ATC’s entry SCM series. The company is admirably route one in how it names things, so ‘SCM’ stands for Sealed Cabinet Monitor, and the number refers to the internal volume. As such, the SCM11 that’s used here for front left and right is an eleven-litre cabinet. Drivers are a 1in soft dome tweeter and a 6in doped paper midbass. For the surrounds, we’re using the SCM7 models, which carry the same tweeter but mount a smaller 5in midbass. You could, of course, go for SCM11s all round, but ATC itself feels the SCM7 is quite sufficient for back-of- the-room duties.

The half-a-metre-wide C3C centre speaker is the larger of two models in the range, and has the same driver complement as the SCM11, and a very similar frequency response (dropping to a claimed 54Hz versus the 56Hz figure of the standmount). On that subject, it’s worth pointing out the stated frequency response of all five passive models might not look that impressive, but ATC is a master of understatement. The one thing you

PRODUCT: Standmount 5.1 speaker system

SCM is ATC’s entry-level, and the SMC 7s are the smallest models

B&W 700 Series; KEF Q Series

ATC SCM 5.1 Review
Magnetic honeycomb grilles keep the soft dome tweeters safe

can be absolutely sure of is that these speakers will achieve their posted numbers and generally a little more too.

The cabinets are sealed, which makes placement fairly straightforward. So long as they are on a sturdy horizontal surface, they’ll largely get on with the job with little interference from walls.

They are also fairly amenable in terms of power required to drive them. While they aren’t the most sensitive speakers around, their impedance is benign and consistent.

Everything is also beautifully made. You can buy more visually spectacular speakers for the same price, but if you press on one of these custom-made midbass drivers you can sense that the travel is perfectly linear and impressively weighty. Both the sub and speakers feel like they have been designed to last as long as you want them to, rather than any particular defined lifespan. ATC can still maintain almost everything it’s ever made, and this feels in keeping with these speakers.

As well as the cherry wood finish here, black ash, satin black and satin white options are available for all models.



Connected to an Anthem MRX 720, the sort of high-spec AV receiver that is able to generate the clean, honest-to- goodness power that these speakers thrive on, the ATCs appear supremely well-engineered. From a listening perspective, there wasn’t an enormous amount wrong with the original C1 subwoofer, so it is surprising how much better the new version is and the effect the internal changes have had.

This manifests itself most clearly when you aren’t simply focusing on the semi-traditional selection of explosions and the like. As a company that makes pro monitors, ATC’s

‘Very few speakers I’ve listened to around this sort of price have such speed, clarity and believability’

ATC SCM 5.1 Review
The heatsink hints at the C1 Mk2 sub’s Class A/B electronics

products have always told you exactly what is going on, and this set is no exception.

The sequence in Once Upon a Time in Hollywood (Blu-ray) where Brad Pitt drives his Karmann Ghia back to his caravan through the lovingly recreated space of late 1960s California is peppered with moments where the soundtrack crosses over to the subwoofer – the exhaust of the Volkswagen, moments in the car radio, and half-a- hundred others. The handover is perfect and not once does the C1 Mk2 drop the ball. This sounds easy, but so many subwoofers are so overt in how they do it that you know as a matter of course that it is part of the LFE channel. Here, it’s beautifully judged.

This is no less apparent with the passive speakers. Quentin Tarantino’s dense and lovely soundtrack unfolds across the ATCs in a way that is perhaps understated but utterly beguiling. As monitors, the tonal realism on offer is effortless, and in a film peppered with sounds you know from reality, this is the difference between things sounding pretty good and entirely immersive. Very little I’ve listened to at this sort of price has such speed, clarity and believability.


Raiding the vault

If you start to lean on the system a little more, by, say, revisiting the ‘safe chase’ sequence from Fast & Furious Five (Blu-ray), this package take the insanity of the soundtrack in its stride. The two SCM11s and C3C at the

ATC SCM 5.1 Review
All the speakers support bi-wiring of their separate tweeter and midbass units

front are particularly effective here because they have an impressive amount of punch in their own right, delivering energy you feel as well as hear even before the C1 Mk2 comes into play, which helps as the safe ploughs through the front of the bank.

In a film that teeters on the edge of being entirely hysterical, this systems keeps its head. It’s not the most effusive or attacking sound, but it sets out to deliver what is on the disc and delivers it unfailingly. It is also possible to run the ATCs very hard without them sounding strained or forward, although having the Anthem MRX 720 on hand is a reminder that reasonably decent amplification is helpful in achieving this.

Upping the scale of onscreen events to ‘fate of the universe’ levels and watching the climactic events of Avengers: Endgame (Blu-ray), the ATCs rise to the occasion in fine style. The subwoofer gives the set-piece scraps deep, clean and detailed low end, and effectively manages to replicate both the onscreen chaos and keep the drumming of the soundtrack a discernible part of the presentation.

There are a numerous rival options around the mark that can go deeper than the C1 Mk2. And if you have a larger room, it may be the case that you would need to look at something heftier (or a second one of these). Yet for a more traditional UK lounge, I don’t doubt its credentials. It has a performance envelope that is hugely exploitable.

And the system’s overall set of abilities – tonal realism, bass integration, soundstaging – aren’t only apparent when you’re driving the bolts out of it. At any level above tickover, the fundamental qualities of the ATCs are present. It’s a real-world performance.

This extends to the speakers’ musical capability. As a hi-fi purist, I would be tempted to treat any stereo content as strictly a job for the two SCM11s, but running as 2.1 with the C1 Mk2, the three enclosures sound like two and, provided that they are remotely on-axis with one another, this effect is very consistent.


High marks

If you have already purchased the C1 subwoofer, I would suggest that – good though the changes are – it doesn’t make sense to replace it with the Mk2 model unless you can pocket some resale cash. This is very much a considered re-work than a brand-new design, and there isn’t much wrong with C1 original. For people shopping for a new subwoofer, however, ATC’s new bass box is something that has to be on your radar. It trades sheer size and power for performance nuance, and should work well with a very wide selection of systems.

And this package serves as a reminder of just how impressive the long-running SCM series remains. I had thought that the more compact SCM7-based system I have auditioned in the past [see HCC # 267] was good, but the switch to the more potent SCM11s and C3C for the front soundstage – without significantly increasing the size of the setup – unearths even greater capability. ATC has never troubled itself much with what the competition is up to, but the competition really ought to be taking notice…



10 Total Score
Highly Recommended ATC SCM 5.1 Review

ATC makes a great pack of speakers that little bit better with a subwoofer that delivers an absolutely outstanding all-round performance.

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DRIVE UNITS: 1 x 6in doped cone midbass; 1 x 1in fabric dome tweeter ENCLOSURE: Sealed FREQUENCY RESPONSE (CLAIMED): 56Hz-22kHz

SENSITIVITY (CLAIMED): 85dB POWER HANDLING (CLAIMED): 300W DIMENSIONS: 232(w) x 381(h) x 236(d)mm WEIGHT: 10.9kg


DRIVE UNITS: 1 x 5in doped cone midbass; 1 x 1in fabric dome tweeter ENCLOSURE: Sealed FREQUENCY RESPONSE (CLAIMED): 60Hz-22kHz SENSITIVITY (CLAIMED): 84dB POWER HANDLING (CLAIMED): 300W DIMENSIONS: 174(w) x 300(h) x 215(d)mm WEIGHT: 7.5kg


DRIVE UNITS: 2 x 5in doped cone midbass; 1 x 1in fabric dome tweeter ENCLOSURE: Sealed FREQUENCY RESPONSE (CLAIMED): 54Hz-22kHz SENSITIVITY (CLAIMED): 88dB POWER HANDLING (CLAIMED): 300W DIMENSIONS: 500(w)x 230(h) x 303(d)mm WEIGHT: 18kg

ATC C1 Mk2 (subwoofer)

DRIVE UNITS: 1 x 12in doped paper woofer ENCLOSURE: Sealed FREQUENCY RESPONSE (CLAIMED): 25Hz-250Hz ONBOARD POWER (CLAIMED): 200W Class A/B REMOTE CONTROL: Yes DIMENSIONS: 360(w) x 450(h) x 400(d)mm WEIGHT: 26.2kg CONNECTIONS: Speaker-level stereo input; LFE input; stereo phono input; stereo line-level output; level, low-pass frequency and phase controls; power/ overload display



ONCE UPON A TIME IN HOLLYWOOD: There’s no Atmos track on this BD, just a 5.1 DTS-HD MA mix (7.1 on the 4K disc) that’s a perfect fit for ATC’s setup, dripping with surround ambience and foot-tapping tunes. The film is a cracker, too.

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