ATC has announced the release of its new SSM (Studio Surface Monitor) series, comprising the SSM12i Pro two-way and SSM25i Pro three-way passive loudspeakers. Designed specifically for wall- and ceiling-mounted installations, the SSM series targets surround and immersive audio environments, particularly in control rooms where space and mounting flexibility are critical factors. Alongside the new monitors, ATC has also introduced the R4-150 Pro, a four-channel power amplifier intended to drive the new models in multichannel configurations.
Both SSM models use a shallow cabinet design combined with proprietary mounting hardware that allows the speakers to sit flat against walls or ceilings while still being angled toward the listening position. The approach is intended to support precise placement for formats such as Dolby Atmos and other immersive systems while maintaining consistent acoustic performance when mounted close to hard surfaces. ATC states that the speakers have been engineered to integrate seamlessly with its existing professional monitoring range, with reinforced cabinets and built-in safety features to support permanent installations.
About ATC (www.atc.audio/professional/)
Surface-Mount Design and Driver Configuration
The SSM12i Pro is a compact two-way passive monitor built around ATC’s SB45-150CLD 150 mm bass and midrange driver, which uses a constrained-layer damping cone to reduce breakup and resonance. High frequencies are handled by ATC’s SH25-76 dual-suspension 25 mm tweeter, crossing over at 2.2 kHz. The sealed cabinet and newly developed crossover network are optimized for use against walls or ceilings, addressing common performance issues associated with boundary mounting.
For larger rooms, the SSM25i Pro employs a three-way design with three proprietary ATC drive units in a sealed enclosure. Low frequencies from 47 Hz to 380 Hz are produced by the SB50-164SC 164 mm bass driver, while midrange duties are assigned to ATC’s SM75-150 75 mm dome driver. High frequencies above 3.5 kHz are reproduced by the SH25-76S tweeter. As with the smaller model, the crossover network has been developed specifically for surface-mounted operation.
Both models can be mounted vertically or horizontally, allowing installers to adapt orientation based on ceiling height and room geometry. The mounting system enables the cabinet to pivot away from the surface for accurate aiming toward the listening position, while reinforced internal steel plates and a safety tether point provide additional installation security.
Multichannel Power and Installation Support
To complement the SSM monitors, ATC has released the R4-150 Pro power amplifier, a four-channel design based on the company’s existing P1 Pro architecture. The amplifier delivers 150 watts per channel and uses Class A-B MOSFET output stages with four independent toroidal transformers in a quad-mono configuration. Balanced XLR inputs and Neutrik NL4 speaker outputs are provided, along with fanless convection cooling for silent operation in control room environments.
The R4-150 Pro is designed to reduce rack space compared to running multiple two-channel amplifiers, making it suitable for immersive systems requiring multiple speaker feeds. Thermal and DC offset protection, along with remote power trigger support, are included for permanent studio installations.
The SSM12i Pro is priced at £2,167 per pair excluding VAT, while the SSM25i Pro is available at £4,667 per pair excluding VAT. The R4-150 Pro amplifier is priced at £3,667 excluding VAT. All three products are available now through authorized ATC distributors.
Will Vance is a professional music producer who has been involved in the industry for the better part of a decade and has been the managing editor at Magnetic Magazine since mid-2022. In that time period, he has published thousands of articles on music production, industry think pieces and educational articles about the music industry. Over the last decade as a professional music producer, Will Vance has also ran multiple successful and highly respected record labels in the industry, including Where The Heart Is Records as well as having launched a new label with a focus on community through Magnetic Magazine. When not running these labels or producing his own music, Vance is likely writing for other top industry sites like Waves or the Hyperbits Masterclass or working on his upcoming book on mindfulness in music production. On the rare chance he's not thinking about music production, he's probably running a game of Dungeons and Dragons with his friends which he has been the dungeon master for for many years.
