ATC SCM20ASL Active Standmount Speakers

The SCM20ASL features a 6” (150mm) bass driver equipped with a substantial 3” (75mm) voice coil and a short-coil, long-gap motor assembly that incorporates ATC’s proprietary ‘SL’ motor technology—designed to significantly reduce distortion in the upper bass and midrange. High frequencies are delivered by ATC’s own 1” (25mm) soft-dome tweeter, which uses a dual-suspension system and a powerful 2.1 Tesla motor for exceptional clarity and detail.

A precision active crossover seamlessly integrates the two drive units. Operating at line level for maximum efficiency, the crossover also includes an all-pass filter to enhance phase alignment and tonal balance through the crossover region. Each driver is powered by its own dedicated Class A/B MOSFET amplifier, carefully optimised to match the demands of its respective frequency range and musical content.

The cabinet is engineered with internal bracing for rigidity and damping materials to suppress unwanted resonances. It’s available in a variety of real wood veneers, satin black or white finishes, and high-gloss lacquer options, allowing it to blend beautifully into any listening environment.

Sound Advice Online - March 2024

Sound Advice 2025 - Exceptional
"ATC has been making active speakers for ages, but the SCM20ASLs couldn’t be better suited to the streamed music age. There’s an appealing purity to speakers such as these, connected to a network player via a relatively simple interconnect run. The look of the speakers may be classic, especially in those real-wood finishes, but this is in every way a very modern system solution." Read the full review.

the-ear.net - July 2025

Editors Choice
"I have to say that the SCM20ASLs have nailed it for me. These apparently simple and relatively compact loudspeakers get to the parts that few others do and make the music so appealing that doom scrolling is no longer a thing. They may not have DSP electronics offering all manner of tweaks but this is very much in their favour. The SCM20ASLs are an all analogue, linear power supplied musical truth conduit that will have you glued to your music for years to come." Jason Kennedy, The Ear, July 2025. Read the full review.

audiograde.uk- October 2025

Audiograde Editors Pick
"They’re also an exceptionally well controlled loudspeaker meaning you’re less likely to be struggling with wayward boom, tricky room nodes or endless hours lost tweaking their positioning to get their acoustic response right. Instead site them at ear level, toe them in and they’ll do the rest. As unlike many rivals, they’re not overly room dependant and instead have a sense of unflappable consistency about them. And I like that, because it means the sounds you’re getting is what is what ATC intended and less what your room is allowing you to hear, and few manufacturers manage this as well as ATC." Andrew Simpson. Read the full review.

Hi-Fi Choice - May 2026

Hi-Fi Choice Recommended

"It’s this unvarnished utterly cohesive rendition of the musical performing arts that’s so consistently rewarding, so unfatiguing, so rare. The tweakers may never agree, but here’s an end-game speaker to die for." Read the full review.

We endeavour to despatch same day for orders placed up to 1pm on available stock items (items with stock message "Usually dispatched within 24 hours"). Please remember to check with us first for a physical stock check if next day delivery is important to you. Any items with stock message "Usually dispatched within 72 hours" are items that we do not hold in stock but order in from the importer or manufacturer as soon as a customer order is received. Occasionally these may be delayed beyond 72 hours due to importer/manufacturer stock levels but we will inform you as soon as we can if this is the case.

UK Orders

We despatch the bulk of our UK mainland items on a 24 hour service – Free of Charge.  Non Mainland locations - Isle of Man, Isle of Wight, the Scilly Isles, the Scottish highlands and Islands, the Channel Islands and Northern Ireland may take a day or so longer and are not Free of Charge. Smaller items are delivered using Royal Mail 24 or special delivery. Larger items are delivered using a courier service such as DPD or UPS.

International Orders:

Due to the nature of our products and brand restrictions we are only able to send certain items internationally. Smaller items are delivered using Royal Mail Small Packets Airmail with International Tracked and/or Signed depending on value of item and availability of the service. Larger International shipments are sent by insured and tracked services using UPS. If there are any delays due to specific customs regulations, etc, you will be contacted by Hifisound or by the courier with a request for any further information required. Customs duties can apply for shipments to any countries outside of the UK depending on where the product you have bought is made. Customers are responsible for all taxes and duties incurred when the items enter their country.

Collect in Store or Home Install

At the request of the manufacturer some items cannot be supplied by mail order but you can click and buy them and then elect to collect them from our store or arrange a home install (if applicable). Applicable items clearly state that they are Collect in store or home install. Once ordered you will receive a message prompting you to contact us by phone or email to arrange for us to deliver and install or to reserve and collect from our store at your convenience, you will also be advised of the delivery time / stock availability as not all Home install / collect in store items are held in stock.