ATC C4 Sub Mk 2 subwoofer debuts optimised 12-inch driver

The Acoustic Transducer Company (ATC) has announced a high-end subwoofer with new proprietary 12-inch driver, for home theatre and audiophile applications.

The C4 Sub Mk 2 active subwoofer system heralds the introduction of the all-new proprietary 12-inch SS75-314SC sub-bass driver, powered by a newly developed 300W class AB amplifier design. Both are hand-built and installed within a substantial cabinet at the company’s Stroud-based production HQ.

The driver has been developed by the R&D team to reproduce the lowest four octaves of the audio band. The design exploits ATC’s signature low distortion short-coil/long-gap configuration with an exceptionally long 30mm magnetic gap, surrounded by a 6-inch/150mm N48M Neodymium magnet, said to be the most powerful yet assembled by ATC.

The redesigned motor system also features a new rubber roll-surround for high excursion capability, a new spider for optimised compliance geometry, and high flow motor venting for low noise and compression.

Air noise within the driver has also been minimised by a large, flared vent running through the centre of the motor structure.

ATC says that the C4 Sub Mk2 delivers an extended low-frequency response while avoiding electronic equalisation. It says a focus on transducer engineering and a marginally larger cabinet volume, reduces phase shift and group delay, aiding integration.

The 300W class AB amplifier design is characterised by dynamic bass with minimal colouration. Two balanced line inputs provide connectivity for stereo or home cinema systems, with two balanced outputs available if you want to daisy-chain subwoofers.

Low-pass filters are analogue, 4th order Linkwitz-Riley, with filter frequency options ensuring optimal integration with partnering speakers. In addition, an industry-standard 80Hz low-pass filter and an 'off' option for use with external processing, are joined by a polarity switch, variable 180° phase adjustment and a stepped attenuator over a 21 dB range for level matching.

The Hand-built the C4 Sub is a style match for ATC’s Classic and Tower series loudspeakers. ATC suggests partnering the sub with the ATC SCM19, SCM20, SCM40, SCM50 and SCM100 active/passive systems and high performance loudspeakers of a similar size.

The 70 litre cabinet, with 25mm thick panels and heavy bracing, is available in Cherry, Black Ash, Walnut and Oak real-wood veneers, as well as Satin Black and Satin White finishes. There’s also the option of premium Rosewood, European Crown Cut Walnut, Burr Magnolia and Pippy Oak real-wood veneers, as well as high gloss over veneers and black/white piano lacquers also available.

With a standard finish, the ATC C4 Sub Mk 2 retails for £3,990. Premium finishes sell for £4,750 (plus £1979 is you opt for high gloss over veneers). The Piano black/white edition retails for £6,140.