ATC announces SCM25A Pro Mk2 compact, three

Mar 21, 2024

ATC is proud to announce upcoming availability of the SCM25A Pro Mk2 as a compact, three-way, high-performance active monitor — maintaining the core of its popular predecessor from which it evolved while refining key areas of design and performance, including replacing the original SCM25A Pro’s OEM (Original Equipment Manufacturer) high-frequency driver with the specialist British manufacturer’s own ‘S-SPEC’ SH25-76S premium soft-dome, dual-suspension tweeter developed with a no-compromise engineering approach (as fitted to the two-way SCM20A Pro and larger, three-way SCM45A Pro, SCM50A Pro, SCM100A Pro, SCM110A Pro, and SCM150A Pro models since 2015).

Formed in 1974 by Billy Woodman to manufacture custom drive units for the professional sound industry, then evolving to produce its own ranges of loudspeaker systems and partnering electronics, ATC as a company clearly has history. Having said that, so does its perennially popular SCM25A Pro compact nearfield monitor — making its presence seen and heard as a valuable tool in studios the world over since its release in 2010 and a product development process that started with key clients in 2008. “Over the past 13 years, the SCM25A Pro has proven to be both exceptionally popular and a valuable tool in the modern studio,” says ATC Technical Sales Manager Ben Lilly.

“However, we knew we could make improvements to performance, and also offer improved consistency with the rest of the Pro product range while ensuring that we had greater control of the manufacturing process.” As a compact, three-way, high-performance active studio monitor, the SCM25A Pro Mk2 is based around a 6.5”/164mm bass driver loaded in a ported/ vented enclosure, tuned to 32kHz and featuring a 3”/75mm diameter port with flared entry and exit to minimise port air noise. Needless to say, its killer combination of exceptional mid-range clarity; high-output, extended bass response; and modest 25-litre/0.9 cubic foot size make it ideal for nearfield monitoring across a wide range of critical applications. All new to the SCM25A Pro Mk2 is its high-frequency driver, ATC having replaced its popular predecessor’s OEM part with its own ‘S-SPEC’ SH25-76S, manufactured in-house with a no-compromise engineering approach (as fitted to the two-way SCM20A Pro and larger, three-way SCM45A Pro, SCM50A Pro, SCM100A Pro, SCM110A Pro, and SCM150A Pro models since 2015).

This driver is a 1”/25mm soft-dome design, handling high frequencies above 3.5kHz, but, unlike almost any other 1”/25mm tweeter on the market, it employs both an upper and lower suspension to better support and control the coil and dome motion. This, therefore, makes for a narrower magnetic gap, resulting in higher magnetic flux, which, in turn, extends the high-frequency response and reduces 3rd harmonic distortion. As ATC R&D Manager Richard Newman notes, “We feel the new tweeter lifts the capability of the SCM25A Pro Mk2 to a higher level, retaining the outstanding balance of the monitor, but extending the high-frequency response and reducing distortion to really help lower-level detail in the high-frequency band cut through. This will greatly aid faster decision-making and outstanding translation outside of the studio.” Meanwhile, mid-band frequencies between 380Hz and 3.5kHz are handled by ATC’s acclaimed 3”/75mm soft-dome mid-range driver, duly combining high-efficiency, high-power handling, low distortion, and wide dispersion characteristics to ensure class-leading performance for the SCM25A Pro Mk2 in this critical frequency range.

As a mainstay of ATC’s Pro product range, this component features in eight models, making certain consistency spans from nearfield through to main monitors. Mid- and high-frequency elements are supported by a 6.5”/164mm proprietary bass driver that takes care of the SCM25A Pro Mk2’s low frequencies below 380Hz. This features a carbon-loaded paper cone while the driver motor employs a short-coil operating in a long magnetic gap, helping to minimise distortion generated by drive force modulation. Additionally, a large 2”/50mm voice coil and generous excursion capability ensure outstanding dynamic range. Rear-mounted, a three-way class A/B amp — termed Tri – AmpPack in ‘ATC-speak’ (as clearly highlighted on the rear panel itself) — actively drives the SCM25A Pro Mk2 with each drive unit having its own dedicated power amplifier.

Audio balanced input is via a rear panel-mounted three-pin XLR and power is via an IEC (International Electrotechnical Commission) mains power inlet. Input sensitivity and Bass boost controls are also accessible to the user. Ultimately, crossovers are 4th order Linkwitz-Riley and all-pass filters are included to optimise the phase response through the crossover regions, improving the tonal quality and imaging, as well as on- and off-axis frequency response. Furthermore, FET (Field-Effect Transistor) peak limiters are included to reduce amplifier ‘hard-clipping’, while POWER/LIMIT is indicated — ‘on’ and ‘active’ — by a front panel-mounted bi-colour LED. It is also worth mentioning that the amplifier is designed and manufactured in-house, just like the speaker drive drive units. All are well worthy of a specialist British loudspeaker drive unit and complete sound reproduction system manufacturer that clearly has history.

Drive Units Bass: 1 x SB50-164SC 8Ω Mid: 1 x SM75-150 16Ω HF: 1 x SH25-76S 6Ω Compact

Low Frequency Cut-off: 47Hz (-6dB, anechoic). High Frequency Cut-off: 25kHz (-6dB). Max SPL: 109dB continuous / 115dB peak (Per pair, IEC Weighted Pink Noise, 1m, anechoic). Sensitivity: +4dBu ref 92dBC (Bass Boot 0dB, Input Sensitivity 1V, Pink noise).

Balanced Input: 1 x Rear Panel Mounted Female XLR, pin 2 hot. Input Impedance: 20kΩ (differential). Input CMRR: >82dB (10kHz). Input Sensitivity: 2.2dBu / 1Vrms for full power Input Sensitivity Control: Continuously Variable from 2.2dBu – 8.2dBu / 1Vrms – 2Vrms (-6dB) Bass Boost Control: Continuously variable from 0dB to +3dB. Crossover Filters: 4th Order Linkwitz-Riley at 380Hz and 3.5kHz. Frequency Response: <2Hz to >200kHz (-3dB). Amplifier type: Grounded Source MOSFET based Class A/B, convection cooled. Output Power: Bass 150W (8Ω), Mid 60W (8Ω), HF 32W (6Ω) THD+N: <0.003%/-92dB (1kHz, 1dB below rated power, 90kHz BW) Limiter: ATC Active FET Momentary Gain Reduction, limiter ‘active’ indicated via front panel LED. Mains Input: 220-230V or 115V – Factory set. Please observe panel markings and labels! Power Consumption: Idle 24W/35VA. 1/8th Power 117W/159VA. Full Power 255W/324VA.\ Heat Output: Idle 82BTU/hr. 1/8th power 335 BTU/hr. Full Power 358BTU/hr.

Net Weight: 25.1kg/55.2lbs Product Dimensions: 271 x 430 x 411mm / 10 11/16th” x 16 15/16th” x 16 3/16th” (H x W x D) https://audiomediainternational.com/magazine/

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