The C1 Sub Mk 2 is a compact (450 x 360 x 400 mm) unit featuring real wood veneer and a hand-built 12-inch (314mm) ATC bass driver connected to a fully discrete Class A/B ATC 200W MOSFET power amplifier.
Alongside that 12-inch driver, there is a 3-inch ribbon voice-coil. ATC states that this delivers clean and dynamic low frequencies down to 25Hz (-6dB).
The new sub is designed for both music and cinema applications with the low-pass filter circuits being comprehensively re-worked for improved integration with partnering speakers.

Controls include a continuously variable low pass filter, a continuously variable all-pass filter and polarity switch. Additionally, there are speaker level L/R inputs, independent L/R RCA line inputs and a summed line output RCA connector to facilitate the daisy-chaining of multiple subwoofers.