ATC: Their SCM19AT Active Loudspeaker System



ATC Loudspeakers is pleased to announce its new SCM19AT active loudspeakers for the home are now shipping in the U.S. consumer Hi-Fi and CI (custom integration) markets.

ATC, Acoustic Transducer Company, formed in 1974 is the renowned manufacturer of handcrafted precision loudspeakers that can be found in the most prominent music and film mastering studios worldwide and the preferred listening choice of recording artists. ATC’s HiFi Series was created to provide the music enthusiast a range of high performance loudspeakers that incorporate all of the features found in ATC’s professional products to enjoy in their own homes – delivering “The Studio Experience at Home”.

The new SCM19AT system is an active version of the Company’s SCM19 award-winner, uniting proprietary, optimized driver/amp pairings in a slender floor standing design.

ATC Loudspeaker Technology’s new SCM19 Active Tower speaker system will deliver the company’s reference-quality audio from an elegantly curved floor-standing design, just 370mm wide and under a meter in height. Identical acoustically to ATC’s award-winning passive SCM19 2-way system but utilizing the 19 liter volume in a slim tower format, the SCM19AT combines high aesthetic appeal with the widely acknowledged performance benefits of ATC active design to create a compelling speaker proposition for music lovers.

The SCM19AT’s braced, sealed and curved multi-layer laminated cabinet, which is precision-finished in cherry or black ash real-wood veneer, provides a rigid and optimally damped environment for the Company’s acclaimed SH25-76 soft dome tweeter and 150mm Super-Linear mid/bass driver. Drive units are individually powered by an upgraded bi-amp pack (also proprietary), comprising ATC’s discrete MOSFET Class A/B modules, providing 32W of continuous power to the HF section and 150W to the bass.

SH25-76 Tweeter

Sharing technology with the renowned ATC soft domed mid-range drive unit, the 19AT’s tweeter employs a unique dual suspension system, designed to suppress rocking modes even at high power output levels. The ATC configuration of a short edge-wound voice coil in a long, narrow magnetic gap ensures exceptionally low distortion throughout the tweeter’s operating band and removes the need for Ferro fluids, which can dry out over time, compromising performance. A complex-shaped, soft-domed diaphragm extends high frequency range and offers a smooth off-axis response. The tweeter’s 15,000 gauss (1.5 tesla) neodymium magnet has a black heat-treated top plate, which dissipates heat away from the voice coil to maintain high power handling and low power compression. A precision-machined 5.5mm rigid alloy waveguide provides optimum dispersion with a flat on-axis frequency response and resonance-free operation.

Bass Driver

The SCM19AT’s 150mm ATC SL mid/bass driver utilizes a carefully weighted doped fabric cone with a 75mm soft dome – exceptional for its broad and even dispersion of mid-band frequencies. The cone is driven by an ‘under-hung’ (short coil/long gap) motor using a huge 9kg ‘Super Linear’ magnet system, which is unique to ATC loudspeaker systems. The 75mm ribbon wire voice coil is meticulously milled and wound in-house by ATC. ATC’s familiar under-hung motor topology maintains linear coil force and inductance, even at high drive levels, keeping distortion low.


The 19AT’s proprietary two-way on-board amp pack design has been revised to reduce noise and distortion (a further -10dB @ 10kHz), while achieving a lower operating temperature for improved reliability. The design includes protection circuits for both DC offset and thermal overload. Mid frequency THD is vanishingly low at 93dB/0.002%, and a very wide bandwidth of 200 kHz ensures the accurate reproduction of musical transients. ATC’s Grounded Source output stage modules are fed by a newly developed two-way active crossover section featuring 2nd order modified Butterworth circuitry with phase compensation for each crossover point. The advantage of active crossovers is that their response remains unaffected by variable voice coil impedance, while the use of phase compensation enables phase coherency at the crossover points, improving the SCM19AT’s tonal balance and enhancing imaging for a pin-point stereo field. As usual system input is via balanced XLR.

The ATC SCM19AT – the first active 19 in the Company’s history – is designed for optimum performance with the grille attached, although the difference in performance without the grill is minimal. Finished in anthracite grey, the metal grille fixes to the cabinet via hidden magnets. Designed and manufactured by ATC entirely in-house, the SCM19AT offers the ownership of a hand-built ruggedly engineered speaker system, world famous for musical accuracy and high power output. Like all ATC products, the SCM19AT is backed by a six-year warranty.

Lone Mountain Audio is the exclusive U.S. distributor for ATC Loudspeakers. Lone Mountain Audio’s president Brad Lunde states, “The new SCM19AT’s are incredibly powerful loudspeakers for the home. The power amplifiers built-in were designed to seamlessly enhance the systems low frequency performance while not interfering with high frequency output and systems to deliver precise details, clarity and pure music reproduction.”


  • New ATC designed and built dual suspension 25mm soft dome HF unit with precision alloy wave guide
  • “SL” spec bass driver with 75mm integral Soft Dome
  • 9kg optimized short-coil/long gap motor assembly
  • On-board grounded source 182 watt Class A/B Bi-amplifier
  • Active filters and overload protection
  • 6 year warranty


  • Drivers: HF ATC 25mm dual suspension Tweeter, Mid/LF ATC 150mm SL Matched Response: +/- 0.5dB
  • Frequency Response (-6dB): 54Hz-22kHz
  • Dispersion: ±80°Coherent Horizontal, ±10°Coherent Vertical
  • Max SPL: 108dB
  • Crossover Frequency: 2.5kHz
  • Connectors: Male XLR
  • Input sensitivity: 1V
  • Filters: 2nd Order critically damped with phase compensation
  • Overload Protection: Active FET momentary gain reduction
  • Fault Protection: DC fault protection and thermal trip. Fault indication on rear panel mounted LED Amplifier Output: 150W LF, 32W HF
  • Cabinet Dimensions (HxWxD): 980x370x344mm (spikes add 25mm to height, grill adds 34mm to depth)
  • Weight: 31kg

Advantages of Active Operation

  • Perfectly matched dedicated amplifiers for each frequency band
  • Active crossover filters with phase correction ensure accurate timbre, excellent imaging and source location
  • A flat magnitude response that is not changed with power input level
  • A 20dB improvement in intermodulation distortion
  • Better controlled low frequency
  • A greater dynamic range for the same input power

SCM19AT U.S. MSRP $9,999 pair

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