ATC Loudspeaker Technology

CLASSIC SCM20ASL Reference Active Compact Loudspeaker

The SCM20SL Classic is ATC's flagship 2-way stand-mount loudspeaker.

Ideal for modestly sized rooms where performance cannot be compromised.
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.
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.

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.
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.

The cabinet is constructed to be heavy and inert with a combination of bracing for stiffness and damping to supress resonance. Bitumastic damping panels are deployed at critical positions to minimise cabinet colouration. It is available in a wide range of finishes.
The SCM20ASL is also available as a floor-standing 'tower' model with identical performance in the form of the SCM20ASLT.

 

Tecnical specifications

Compact closed housing
Active 2nd order Linkwitz-Riley switches
2 x Class A/B MOSFET amplifiers, 200W (woofer) + 50W (tweeter)
User-adjustable input sensitivity and bass shelf controls
Handcrafted in England
6 year guarantee

Acoustic specifications

Woofer/midrange driver: 1 x 150 mm/6", SB75-150SL 8 Ω
High frequency driver: 1 x 25mm/1", SH25-76S 6Ω
Lower limit frequency: 55 Hz (-6 dB, reflection-free)
Upper limit frequency: 25 kHz (-6 dB)
Crossover point: 2.2 kHz
Max SPL: 108 dB continuous, 114 dB peak (per pair, IEC Weighted Pink Noise, 1 m, anechoic)

Electrical specifications

Balanced input: 1 x rear mounted XLR socket, pin 2 hot
Input impedance: 20 kΩ (differential)
Input CMRR: >60 dB (10 kHz)
Input Sensitivity: 2.2dBu/1Vrms at full power
Input sensitivity control: -6 dB switchable, -6 dB variable. Overall setting 2.2 dBu/1 Vrms to 14.2 dBu/4 Vrms
Bass Shelf: -2 dB to +3 dB, switchable in 1 dB steps
Crossover filter: Linkwitz Riley 2nd order
Output power: Bass 200W (8Ω), Tweeter 50W (8Ω)
THD+N: <0.0017%/-95 dB (1 kHz, 1 dB below rated power, 90 kHz BW)
Frequency response: <2 Hz to >200 kHz (-3 dB)
Limiter: ATC Active FET Momentary Gain Reduction
Electronic amplifier protection: amplifier DC offset and over temperature (both indicated by LED on the back)
Power consumption: idle 26W/41VA, 1/8 power 116W/161VA, full power 312W/398VA

Size and weight

Net weight: 27kg/piece
Dimensions (HxWxD): 450 x 250 x 425 (including active module and handles) mm
Gross shipping weight: 31.3 kg
Box dimensions (HxWxD): 600 x 380 x 560 mm
A box contains a single speaker

The retail price is for 1 pair.