Сабвуферы — ATC C4 Sub Mk2

The C4 Sub Mk2 is an active 12-inch subwoofer from ATC, handcrafted in England and intended to bring the company's studio monitoring engineering into home systems. ATC positions it as a partner for its passive SCM19, SCM20, SCM40, SCM50 and SCM100 loudspeakers, and the same driver and amplifier are combined in the cabinet as one tuned system. It works in stereo, home cinema and AV installations alike.

Key specs that matter

The single SS75-314SC drive unit measures 314 mm and has an 8 ohm rating. ATC gives a low frequency cut-off of 22 Hz at -6 dB in half space, and the electronics run from under 2 Hz at -3 dB up to 320 Hz at -6 dB. The built-in amplifier produces 300 W into 8 ohm with THD+N below 0.003% at 100 Hz at full output. Maximum level at 1 m in half space is 110 dB continuous and 116 dB peak, and sensitivity is quoted as +4 dBu for 88 dBC. The cabinet stands 568 mm high, 464 mm wide and 500 mm deep, weighs 42 kg, and draws 8 W at idle and 500 W at full power.

Engineering and use context

ATC designed the SS75-314SC in-house to handle content below 160 Hz. It pairs a short voice coil with a very long magnetic gap, a layout ATC uses to hold distortion down through the whole dynamic range. Amplification comes from a Class A-B stage using grounded source MOSFETs, cooled by convection with no fan. Four low pass settings are available - 50, 65 and 80 Hz and a widest setting matching the electronics' top frequency - each a 4th order Linkwitz Riley slope. Gain can be set to 0, +6 or +10 dB, level trims from 0 to -11 dB in 1 dB steps, phase turns continuously from 0 to 180 degrees, and a polarity switch is fitted. Connections are two balanced XLR inputs and two balanced XLR outputs on the rear panel, wired pin 2 hot. The natural gloss or satin veneers include black ash burr, magnolia burr, poplar, cherry, European walnut, oak, pippy oak, rosewood and walnut, with piano black and piano white lacquer as well, and other veneers can be ordered specially. ATC covers the unit with a 6-year warranty.

Pairing

Because the inputs are balanced XLR only, the C4 Sub Mk2 is best fed from a balanced preamp or processor output, or an adapter from a single-ended line output. The XLR outputs pass the signal on to power amplifiers or active speakers, and the widest filter position lets an external crossover in an AV processor handle bass management instead.

Alternatives

The ATC C6 Sub is the larger choice, pairing a 375 mm SL driver with a 450 W amplifier in a 60 kg cabinet.