SCM20ASL
ATC SCM20ASL Active Standmount Speakers
The SCM20ASL is a 2-way active stand-mount loudspeaker and is the ideal choice in modestly sized rooms where exceptional musical reproduction is the goal. Its sealed cabinet design ensures well controlled, clean bass playback, even in smaller spaces and/or when located close to walls. The bass driver, HF driver and amplifier are all designed and manufactured in-house by ATC and to the highest standards to form a system that is hard to match with a passively driven system.
Input to the loudspeaker is via rear panel mounted balanced XLR (but the input can be driven from an un-balanced output if needed). There are user controls for input sensitivity and low frequency shelf cut/boost. The input sensitivity control allows the user to tailor the input gain to suit their source/pre-amplifier combination, reducing noise and optimising volume control operation. The low frequency shelf control gives the user the option to subtly adjust the bass response to suit their room, loudspeaker postion, and/or their personal taste.
The loudspeaker crossovers are active, analogue, 2nd order Linkwitz-Riley and an all-pass filter is included to optimise the phase response through the crossover region, resulting in far improved tonal balance and stereo imaging. Power is provided by on-board class A/B MOSFET power amplifiers, capable of delivering 200W and 50W continuous power to the bass and HF drivers respectively. The speaker is supplied with a removable grille, wrapped in acoustically transparent cloth.
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.
Technical Specifications
ACOUSTIC 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).
ELECTRONIC SPECIFICATIONS
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
PHYSICAL SPECIFICATIONS
Net Weight: 24.3kgs
Dimensions: HxWxD 450x250x411mm
