Полочная акустика — ATC SCM12i Pro

The SCM12i Pro is the installation variant of the SCM12 Pro, a compact two-way passive nearfield monitor in ATC's professional range. ATC designed it for fixing into recording, post-production, broadcast and film studios, and its size suits surround and multichannel mixing as well as Dolby Atmos, DTS:X and Auro 3D rooms. The two versions perform identically in acoustic terms - the i model adds fixing hardware and weight.

Key specs that matter

ATC fits the SH25-76, a 25 mm soft dome tweeter with dual suspension and a 6 ohm rating. Below the 2.2 kHz crossover a 150 mm bass/mid driver with Constrained Layer Damping (CLD) takes over. Amplitude linearity holds within 2 dB between 80 Hz and 16 kHz, while the freestanding -6 dB limits are 56 Hz and 22 kHz. A pair can produce 108 dB continuous SPL at 1 m. Coherent dispersion covers plus or minus 80 degrees horizontally and 10 degrees vertically. Nominal impedance is 8 ohm and ATC suggests amplifiers from 75 to 300 W. The cabinet is 400 mm high, 238 mm wide and 235 mm deep, and each unit weighs 15 kg against 11 kg for the standard SCM12 Pro.

Engineering and use context

The CLD treatment of the bass/mid cone is meant to cut harmonic distortion in the midrange and to improve both magnitude linearity and off-axis behaviour. Its voice coil is hand-wound from edge-wound flat OFHC copper ribbon, and the motor system is vented front and rear to lower airflow noise. In the tweeter, the second suspension suppresses rocking modes of the diaphragm, so no ferrofluid is required in the gap. The passive crossover drives a bi-wire panel whose upper terminal pair feeds the tweeter and whose lower pair feeds the woofer, with removable links for single-cable use. For mounting, the back of the cabinet carries four M8 threaded points in the standard 69.9 x 127 mm pattern, supplied with M8 x 30 button head screws, plus an M8 eyebolt at the top rear corner that must always be tied to a separate safety point. ATC lists compatible pan and tilt wall and ceiling mounts from Adaptive Technologies and Konig & Meyer, and any bracket used has to be rated above the speaker's weight.

Pairing

The extended bass response comes at the cost of relatively low sensitivity, so ATC advises amplifiers able to supply more than 150 W continuous into the rated load. ATC's own P1 Pro, rated at 150 W per channel, is the partner ATC names, and speaker cable of at least 2.5 mm2 per conductor is advised, heavier for runs beyond 5 metres.

Alternatives

The ATC SCM19 is a larger two-way passive stand-mount from the Entry Series, with a 150 mm SL mid/bass driver and 85 dB sensitivity.