Featuring wholly ATC designed and built drivers and amplifiers, the new SCM40A system is an active version of the SCM40 three-way floor standing speaker, launched in late 2013. The SCM40A utilises ATC’s soft dome dual-suspension SH25-76 tweeter together with the company’s signature 75mm soft dome mid-range and a 164mm short coil/long gap (under-hung) bass unit. The drivers are powered individually by a proprietary ATC tri-amplifier pack, upgraded from the version employed by the Pro SCMA 25 monitor.  Housed in a curved, laminated cabinet, the SCM40A is the first of the ‘Passive’ Series speakers to be made active.

Sharing technology with the ATC soft domed mid-range drive unit, the new tweeter employs a dual suspension system “suppressing 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 its operating band and removes the need for ferrofluids, which can dry out over time, compromising performance” says the company’s press release. .

The tweeter’s 15,000 gauss (1.5 tesla) neodymium magnet has a black heat-treated top plate, designed to dissipate 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, a flat on-axis frequency response and resonance-free operation.

ATC’s 75mm mid-range dome is the latest version of the SM 75-150 soft dome midrange driver introduced by ATC in 1976. It uses a hand-doped acrylic diaphragm, dual suspension system and a highly linear drive system. 

The SCM40A’s 164mm bass driver utilises a hand-coated carbon-paper diaphragm driven by an ‘under-hung’ (short coil/long gap) motor and utilising a massive, optimised magnet assembly. In this application paper pulp is selected for the ideal balance of mass, damping and rigidity. 

The on-board discrete MOSFET class AB three-channel amplifier utilising ATC’s Grounded Source® output stage delivers 25W to the HF driver, 60W to mid and 150W to the bass driver for a total of 235 watts continuous power. Input is via balanced XLR.

The crossovers are all active, 4th order modified Butterworth with phase compensation circuitry for each crossover point.

The SCM40A has a curved cabinet construction braced and laminated for high rigidity and damping and finished in real cherry or black ash veneer. It is designed for optimum performance with the grille and fixes to the cabinet via hidden magnets. According to ATC tradition, the model number represents internal cabinet volume in litres.

The Worldwide launch will be held on January 6, 2015 at CES, Venetian, floor 29, room 325.  

Specification

Drivers: HF ATC 25mm dual suspension Tweeter, Mid 75mm ATC Soft Dome, LF ATC 164mm SC

Matched Response: ±0.5dB

Frequency Response (-6dB): 48Hz-22kHz

Dispersion: ±80° Coherent Horizontal, ±10° Coherent Vertical

Max SPL: 112dB

Crossover Frequencies: 380Hz & 3.5kHz

Connectors: Male XLR

Input sensitivity: 1V

Filters: 4th 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, 60W MF, 25W HF

Cabinet Dimensions (HxWxD): 980x370x344mm (spikes add 25mm, grill adds 34mm to depth)

Weight: 36kg (each) 

Typical retail price (inc VAT): £6280 pair

Availability: January 2015