ATC Active Loudspeakers - Soundstage Hi-Fi’s Expert Guide
ATC is one of the best-kept secrets in hi-fi. This company has been making drive units and loudspeakers in the Gloucestershire countryside since the ‘70s, yet the brand has a low profile in all but the studio world. In the US, it is only known for producing pro audio speakers, but therein lies its strength. Many years of experience in providing monitors for the most demanding clients in the audio world mean that ATC speakers are phenomenally capable and almost bombproof. You want loud and clean, look no further.
But ATC is about more than power, they make a wide range of active and passive speakers at extremely competitive prices, we challenge anyone to find a loudspeaker that offers the same component and build quality in a product made outside of the Far East. You will find it very hard to find one that comes anywhere near the price/performance ratio that ATC offers.
Their pro heritage means that active loudspeakers are a speciality. These speakers incorporate amplifiers in the cabinet, with one power amplifier per driver and an electronic crossover to split the signal. To build a system with active speakers, all you need is a source, such as a CD player, and a preamplifier, or, for a complete minimalist approach, a streamer with a volume control onboard.
Where do you start with ATC Active Speakers?
There are several classic active speakers in the ATC range and we thought it might be helpful to pick out what the differences are and how this impacts performance. All three have separate amps for each drive unit, so three amplifiers per speaker. This not only confers considerably more power than most separate amplifiers but also has the active advantage, which is a direct connection between amp and driver. In regular passive speakers there is a crossover between the signal from the amp and the drive units, this significantly reduces the amount of control that the amp has over the drivers. It’s the reason why all professional applications including concert rigs have active loudspeakers, you can’t produce continuous high sound pressure levels (SPL) without distortion in any other way.
ATC SCM40A
The entry-level three-way active speaker in the range is the SCM40A. This is a relatively compact tower speaker for ATC that stands just under a metre high yet weighs in at a respectable 36 kilos. It combines a soft dome tweeter with the company’s legendary 75mm midrange dome and a six and a half inch bass driver, all of which are made in-house. Power amplification consists of 32 Watts for the tweeter, 60W for the midrange and 150W for the bass – a total of nearly 250W for the whole system.
The SCM40A is designed for normal living rooms, the sort typically found in British homes. It will deliver high sound quality and musically engaging results, very engaging in fact, especially if you like to play your sounds at an entertaining volume level. Build quality is very high and the wood veneered cabinets attractive if not elaborate, for a fancy finish you need to aim a little higher. The SCM40A was built to allow those on limited budget to enjoy the potential of their active designs and it does so in spades.
“The SCM40A was built to allow those on a limited budget to enjoy the potential of their active designs and it does so in spades.”
ATC SCM50ASL
The ATC SCM50ASL is the loudspeaker that made ATC’s name in the domestic hi-fi scene, when launched there was nothing that could get near to its power, control and clarity of detail and arguably there isn’t much competition today. In its stand mount guise, there is also a tower version, it makes no apology for its form following function appearance. Closely related to its pro audio counterpart this isn’t the prettiest speaker on the market but it makes up for it with a sound that will hook you in and not let go.
As with the SCM40A this is a three-way active design but there’s more difference than size, the SL suffix in the name indicates that it has Super Linear drive units. These are more refined examples of the breed that can resolve finer details such as the scale and nature of a venue, and the precise placement of the musicians within it. With all manner of music they will deliver a huge soundstage that fills the room, recording allowing. One thing that this speaker will reveal is the nature of the recording, ATCs are not designed to flatter but they let you hear of the artist’s intent and that’s what counts.
The drivers consist of tweeter and midrange domes of the same size as those in the SCM40A allied to a nine inch bass driver. These are powered by high quality amplifiers that deliver 50 Watts to the tweeter, 100W to the mid and 200W for the bass. These are all RMS power ratings by the way, this is a 350W powered loudspeaker that means business. Naturally the SCM50ASL can drive large rooms with high levels of power and extends deep into the bass, its response is quoted as 38Hz, which is low enough to shake any piece of furniture and even your internal organs if you wind the wick up too far.
ATC SCM50ASL Loudspeaker custom install - North London
“With all manner of music the SCM50ASLs will deliver a huge soundstage that fills the room”
ATC SCM100ASL
The ATC SCM100ASL Loudspeaker is not the largest domestic speaker that ATC makes, but it’s as big as even the most power hungry music lover is likely to require. This is essentially an upscaled version of the SCM50ASL with a larger bass driver, a 12.5 inch unit that can move air like you wouldn’t believe. The three drivers are backed by the same array of power amplifiers as the 50 but the larger 100 litre volume of the cabinet means that it is inherently more efficient, in other words those 350 Watts will give you more distortion free volume in the SCM100ASL.
The extra scale of bass driver and cabinet means that the sound this monolith produces has a greater ease than its more compact sibling, and alongside this it delivers deeper bass. The figure quoted is 32Hz which doesn’t sound a lot but this is a lab measurement not an in-room one. That makes all the difference because rooms reflect bass and in them the SCM100ASL can reach lows that you may not have heard outside of a thunderstorm. It means that you hear the fundamentals of the lowest notes be they acoustic or electronic, the effect is to bring a solidity and scale to the sound that cannot be matched.
Whether you want to hear Kraftwerk live as it sounded at the concert or reproduce a full orchestra at home, the SCM100ASL is the speaker for the job. Partner it with a decent preamplifier and fabulous source and you have a recipe for home entertainment that’s truly the next level.
All three of these active ATC speakers offer superb sound for their asking price, there are numerous reviews online to back this up, and I personally have spent many very happy hours enjoying great music with these speakers. If you want to enjoy the visceral impact of your favourite tunes, to be able to hear into the heart and soul of the artists behind them, these ATCs will get you closer than you can imagine.
Jason Kennedy is Soundstage Hi-Fi’s resident expert & Editor of The Ear Magazine.
“You want loud & clean, look no further.”