SCM20ASL CLASSIC
Active 2-way stand-mount loudspeaker
The SCM20SL Classic is ATC’s flagship 2-way stand-mount loudspeaker. Ideal for modestly sized rooms where performance cannot be compromised.
ATC DRIVE UNITS
The loudspeaker is available in both PASSIVE and ACTIVE versions. Both versions employ ATC’s renowned drive units which are painstakingly designed and manufactured by ATC in the UK.
SEALED CABINET DESIGN
Its sealed cabinet design ensures precise timing and excellent low frequency output below the cut-off. The combination of ATC mid/bass and soft-dome tweeter delivers mid-range & high frequency of exceptional clarity and the driver component’s shared design philosophy ensures the parts work seamlessly together.

ON-BOARD 250W AMP PACK
The active SCM20ASL features an on-board 250W Amp Pack. Simply pair with a suitable pre-amplifier, DAC/pre or streaming-pre-amp for stunning results.
ACTIVE CROSSOVER AND AMPLIFICATION
The active SCM20ASL replaces the passive crossover and the driving amplifier of a ‘conventional’ system with a precisely matched ‘Amp Pack’, mounted to the rear of the loudspeaker cabinet. The electronic system consists of a balanced input feeding a 2nd order active electronic crossover which, in turn, feeds a pair of class A/B power amplifiers, carefully tailored to the exact requirements of the mid/bass and high-frequency drive units.
The active crossovers deliver greater precision in both level and timing and the two power amplifiers directly coupled to the drive units result in an improvement in control and dynamic range vs a passive system.
CABINET CONSTRUCTION
The cabinet is constructed to be heavy and inert with a combination of bracing for stiffness and damping to suppress resonance. Bitumastic damping panels are deployed at critical positions to minimise cabinet colouration. It is available in a wide range of finishes.
ALSO AVAILABLE AS A TOWER
The SCM20ASL is also available as a floor-standing ‘tower’ model with identical performance in the form of the SCM20ASLT.
CABINET FINISHES
Natural










Gloss









Other veneers and finishes can also be supplied to special order.
SPECIFICATIONS
- Mid/Bass driver: 1 x 150mm/6″, SB75-150SL 8Ω
- High Frequency Driver: 1 x 25mm/1″, SH25-76S 6Ω
- Low Frequency Cut-off: 55Hz (-6dB, anechoic)
- High Frequency Cut-off: 25kHz (-6dB)
- Matched Response: +/-0.5dB
- Crossover Point: 2.2kHz
- MaxSPL: 108dB continuous, 114dB peak (per pair, IEC Weighted Pink Noise, 1m, anechoic)
- System Sensitivity: 85dBC SPL (@1m, pink noise, -18dBu, 1V input sens. 0dB bass boost)
- Balanced Input: 1 x Rear Panel Mounted Female XLR, pin 2 hot
- Input Impedance: 20kΩ (differential)
- Input CMRR: >60dB at (10kHz)
- Input Sensitivity: 2.2dBu/1Vrms for full power
- Input Sensitivity Control: -6dB switchable, -6dB variable. Total adjustment 2.2dBu/1Vrms to 14.2dBu/4Vrms
- Bass Shelf: -2dB to +3dB, switchable in 1dB steps
- Crossover Filters: 2nd Order Linkwitz Riley
- Amplifier type: Grounded Source MOSFET, class A/B, convection cooled
- Output Power: Bass 200W (8Ω), H.F. 50W (8Ω)
- THD+N: <0.0017% /-95dB (1kHz, 1dB below rated power, 90kHz BW)
- Frequency Response: <2Hz to >200kHz (-3dB)
- Limiter: ATC Active FET Momentary Gain Reduction
- Electronic amp protection: Amplifier d.c. offset and over-temperature (both indicated by rear panel LED)
- Mains Input: 220-230V or 115V, factory set. Please observe panel markings and labels!
- Power Consumption: Idle 26W/41VA. 1/8th Power 116W/116VA. Full Power 312W/398VA
- Heat Output: Idle 89BTU/hr, 1/8th Power 311BTU/hr, Full Power 382BTU/hr
- Net Weight: 24.3kg
- Dimensions: HxWxD 450 x 250 x 411mm






