Magazine Archive

Home -> Magazines -> Issues -> Articles in this issue -> View

Soft Centres

ATC SCM10 Compact Studio Monitors

ATC's smallest speakers to date set new standards in near-field monitoring excellence.

These deceptively small, soft-domed loudspeakers look set to redefine the standard in compact, near-field monitoring. Paul White checks out a pair.

TC have built their reputation on sonic integrity backed up by no-compromise engineering, which you might think would be a recipe for worldwide acceptance. But the loudspeaker world is a fickle place, and people have been listening to inaccurate designs for so long now that many accept what they hear as being the norm and suspect anything that sounds in any way different. Nevertheless, over the past two or three years, the message has finally started to get through and ATC's designs now tend to be held up as the yardstick against which other models are judged.

Until recently, ATC steered clear of two-way speaker systems as, understandably, they didn't want to compromise their design aims, but the development of a bass/mid driver which combined aspects of both a cone bass driver and a soft-dome mid-range unit led to the launch of the SCM20, arguably one of the finest, if not the finest, two-way loudspeaker ever put into production. While the SCM20 is physically little larger than a Yamaha NS10, an engineer whom I know very well (Hi Mick!) managed to put his back out while lifting one of these — which gives you some idea of how solidly they're engineered. The speaker under review, the diminutive SCM10, is a tiny two-way system based on the design principles that made the SCM20 possible. It is capable of incredible performance, with the proviso that you need plenty of amplifier power to drive it. Though it only measures 370mm x 175mm x 260mm deep, the SCM10 is surprisingly heavy and comes in a choice of black ash or rosewood finishes to appease those hi-fi users with aesthetically critical wives/husbands.

The design employs a bass/mid-range driver which can be thought of as a bass cone with a central mid-range soft dome. This is made of damped, soft polyester weave cloth to minimise colouration and the mechanics of the cone construction act as a mechanical crossover, allowing the driver to work effectively up to the crossover point of 2.8kHz; in effect, this allows a two-way system to behave more like a three-way design.

Despite its small diameter, the bass/mid driver uses a 45mm-diameter ribbon wire voice coil, which is just 5mm long, working in a 15mm-long magnetic gap. The cone assembly is free to move up to 20mm in either direction, which, doubtless, accounts for the amount of true bass this little system can generate. The magnet assembly on this unit is also quite enormous compared to the size of driver. A modified Vifa soft-domed tweeter handles the top end, the crossover being a passive fourth-order design built on a heavy, double-sided circuit board using high-grade components, including air-cored inductors. Connection is made to the speakers via heavy screw terminals drilled with sensibly large holes to allow large-diameter speaker cable to be used.

The frequency response is quoted as being 80Hz to 12kHz (within 2dB) with 6dB down points at 65Hz and 20kHz. As SCM10s have a sensitivity of only 80dB/W/m, it means that a large amplifier is needed in order to get them to deliver their maximum continuous SPL at one metre of 103dB. In fact, amplifiers of less than 100 Watts per channel are not recommended at all — the ideal amplifier will deliver between 250 and 300 Watts per channel.

Though ATC loudspeaker systems are capable of very high SPLs, many people hearing them for the first-time misinterpret their lack of distortion as a lack of sheer volume — until they try to talk over them. Some engineers will never accept that a speaker can be loud if it isn't rasping under the stress of overload!

Indeed, all ATC's monitors are surprisingly low in distortion, partly due to the highly-damped cloth used in the diaphragm construction. Another parameter which ATC take just as seriously is dispersion, the argument being that the reverberant field must be spectrally accurate as well — and not just the direct sound. The relatively small physical size of the dome mid-range and tweeter units enables them to work as effective point sources, giving an excellent off-axis response.

Feel The Width

Before even commenting on the sound quality, it has to be said that the stereo imaging produced by these little speakers is remarkable. Because of the excellent dispersion, sitting at the exact apex of the listening triangle is not vital and you can move around the mixing desk without compromising the sound unduly. It needs to be stressed, though, that speakers of this pedigree should, ideally, be mounted upright on proper stands a foot or so behind the mixing desk — not perched on their sides on the meter bridge.

"It's like being able to listen 'through' the loudspeakers to the music behind them, rather than being forced to listen to the loudspeakers themselves."

By way of subjective sound quality, the SCM10 is a neutral speaker in that it doesn't hype up the sound by adding sizzle, edge, bass peaks or anything else that could detect. This can make it sound a little restrained in comparison with more overtly coloured designs, but when you actually listen to the detail within the sound, the ATCs are invariably the more revealing. It's like being able to listen 'through' the loudspeakers to the music behind them, rather than being forced to listen to the loudspeakers themselves.

Low bass notes are clearly audible, but at low listening levels, the speaker doesn't give the impression of being particularly hard-hitting. This is a direct result of ATC's 'honesty before flattery' policy, and the lack of box porting causes the bass to roll off very smoothly rather than being artificially tuned to pick out kick drum beats in the 80Hz region, as so many smaller designs appear to do. Cranking up the drive level changes things somewhat, and the bass really starts to take on a life and energy out of all proportion to the size of the units. Removing the grilles shows the bass drivers to be moving over a considerable distance, with the result that bass instruments and kick drums are reproduced very cleanly and accurately. Even at high power levels, the sound remains clean which, as pointed out earlier, leads some people to think that they're not getting as much volume as they are; the positive side to this is that you can work on any ATC speaker for long periods without experiencing fatigue — unless the fatigue-inducing element is part of the source material!

I found that classical music recordings were reproduced with stunning realism, while assorted pop music recordings served mainly to show up how different mixes from different producers, engineers and studios actually sound. In this respect, the SCM10s are perfect tools for qualitative assessment, as they have the ability to reveal the minutest traces of programme distortion or bad equalisation.


ATC loudspeakers are by no means cheap, and the SCM10 represents the first ATC model to be priced below £1000 per pair. Their compact nature makes them ideal for use as serious near-field studio monitors, and the fact that they are small enough to tuck into the back of the car provides producers with a viable portable monitoring system of unsurpassed accuracy. In this respect, the only down-side is that you also have to cart around a large amplifier of between 200 and 300 Watts per channel to really get the best from these monitors.

I'm permanently amazed that so many engineers rely on indifferent domestic monitors to evaluate work produced on studio gear costing hundreds of thousands of pounds, and if speakers like the ATC SCM10s can help improve this situation, then they get my vote. Some will no doubt say that they have managed perfectly well without them until now and so why change, but after listening to a wide selection of CDs under critical conditions, it becomes patently obvious that they haven't managed at all well — there are some absolutely appalling mixes around and the better the speakers you use to audition them, the worse they sound!

I have a great respect for all ATC's speaker designs, but in designing first the SCM20 and now the SCM10, I feel they have redefined the standard for two-way monitor design. Not everyone will like the sound of a monitor that tells the uncompromising truth, but if we're to have any kind of standardisation in the audio industry, then accuracy has to be put firmly before flattery.

Further Information
SCM10s £950 per pair including VAT (standard finish).

HHB Communications, (Contact Details).

Previous Article in this issue

Studio Security

Next article in this issue

Automatic Pilot

Recording Musician - Copyright: SOS Publications Ltd.
The contents of this magazine are re-published here with the kind permission of SOS Publications Ltd.


Recording Musician - Sep 1992

Donated & scanned by: Mike Gorman

Gear in this article:

Monitors/Speakers > ATC > SCM10

Gear Tags:

Monitor Speakers

Review by Paul White

Previous article in this issue:

> Studio Security

Next article in this issue:

> Automatic Pilot

Help Support The Things You Love

mu:zines is the result of thousands of hours of effort, and will require many thousands more going forward to reach our goals of getting all this content online.

If you value this resource, you can support this project - it really helps!

Donations for June 2020
Issues donated this month: 0

New issues that have been donated or scanned for us this month.

Funds donated this month: £0.00

All donations and support are gratefully appreciated - thank you.

Please Contribute to mu:zines by supplying magazines, scanning or donating funds. Thanks!

Monetary donations go towards site running costs, and the occasional coffee for me if there's anything left over!

Small Print

Terms of usePrivacy