Description
ATC SCM40 Passive Floorstanding Loudspeaker
Accuracy, Speed, and Insight at an Exceptional Price
The ATC SCM40 is a three-way passive floorstanding loudspeaker that delivers a level of transparency, accuracy, and speed that Hi-Fi Choice described as normally only expected from loudspeakers at three or four times its price. Built around ATC’s in-house designed 25mm dual suspension soft dome tweeter with precision alloy waveguide, a 75mm soft dome midrange driver, and a 164mm short coil bass driver, all incorporating massive optimised motor assemblies, the SCM40 offers a matched response of plus or minus 0.5dB across its frequency range, a flat impedance curve for easy amplifier loading, and a maximum SPL of 112dB. With over 40 years of ATC transducer engineering behind every driver, the SCM40 is a loudspeaker of genuine professional heritage made fully accessible to the home listener.
ATC Dual Suspension Tweeter Technology
The SCM40’s 25mm soft dome tweeter with precision alloy waveguide incorporates ATC’s unique secondary suspension component, which constrains the moving assembly to travel only in the axial direction. This design suppresses rocking modes, lowers distortion, and negates the requirement for ferro-fluid, allowing the magnetic gap to be made smaller for improved power handling and longer-term optimal performance. The tweeter motor assembly employs a magnetically annealed top plate and a huge N48M Neodymium ring magnet, optimised using finite element analysis to achieve a flux density of over 2.0T in the magnetic gap, reducing odd harmonic distortion to below minus 70dB across the operating band. A FEA-optimised low-mass diaphragm, Kapton former with copper clad aluminium ribbon voice coil, and acoustically absorptive felt plug at the rear of the diaphragm complete a tweeter design of extraordinary engineering depth.
Three-Way Driver Integration and Passive Crossover
The ATC 75mm soft dome midrange driver handles the critical vocal and instrumental band from the 380Hz crossover point, and the ATC 164mm short coil bass driver provides the low-frequency foundation, extending the SCM40’s response to 48Hz at minus 6dB. The crossover frequencies of 380Hz and 3.5kHz are precisely chosen to keep each driver operating well within its optimal range, and the flat impedance curve ensures the SCM40 presents an easy and consistent load to any amplifier rated between 75 and 300 watts. Tri-wire binding posts provide the connectivity flexibility for those who wish to explore bi-wiring or tri-wiring configurations.
Finish Options and Specification
The SCM40 is available in veneer finishes of Cherry and Black Ash, and painted finishes of Satin Black and Satin White, accommodating a wide range of room aesthetics. At 980 x 370 x 305mm and 31kg per cabinet, the SCM40 is a substantial and purposefully engineered loudspeaker backed by ATC’s standard six-year warranty.
KEY FEATURES:
- Three-way passive floorstanding loudspeaker with ATC-designed and built driver complement throughout
- ATC 25mm dual suspension soft dome tweeter with precision alloy waveguide and N48M Neodymium motor assembly
- ATC 75mm soft dome midrange driver
- ATC 164mm short coil bass driver with massive optimised motor assembly
- Matched response: plus or minus 0.5dB
- Frequency response: 48Hz to
