ATC SCM25A Pro Compact 3-Way Active Monitor

Rated 5.00 out of 5 based on 2 customer ratings
(2 customer reviews)


7″, active 3-way speaker with 235-watt tri-amplification

- or -
Buy Now with Westlake Pro Credit Card
Special 12-Month No-Interest Financing
Westlake Pro Best Price Guarantee Badge

We will beat any price. Learn more »

  • FREE 2-Year Warranty Included
  • |
  • FREE Shipping
  • |
  • Expert Service
SKU: ATCSCM25APRO Categories: , Brand:

The ATC SCM25A Pro is a compact 3-way monitor with hand-built 7″ woofer, 3″ soft-dome midrange driver, proprietary 1″ dual-suspension tweeter, and 235-watt A/B amplifier

The ATC SCM25A Pro grants home and project studios, as well as professional studios, entry into the world of ATC-quality monitoring. A 3-way monitor featuring a 7″ hand-built carbon-paper cone woofer, 3″ midrange done, and 1″ soft-dome tweeter, the ATC SCM25A Pro is powered by a 235-watt, class A/B 3-way amplifier, and designed to sit horizontally on a meter bridge. Known for their linear response throughout the audible spectrum, and in particular, the all-important midrange, the SCM25A Pro response is flat from 74Hz to 17kHz (±2dB). It is also capable of being mounted on a 19″ rack for outside broadcast trucks.

ATC SCM25A Pro 3-way compact active monitor in one take:

  • 1″ neodymium soft dome tweeter
  • ATC hand-built 3″ soft-dome midrange driver
  • ATC hand built 7″ carbon-paper cone bass driver
  • Onboard, grounded-source 235W class A/B 3-way amplifier
  • Compact size with high output and low cut-off frequency
  • 19″ rack mountable
  • 6-year warranty

Who Using ATC?

ATC users range from artists such as Sting, Pink Floyd, The Rolling Stones, Eric Johnson, Enya, Kate Bush, film composer, James Newton Howard, and many more. ATC users include producer-engineers known for their discriminating ears, such as Bruce Swedien, Hugh Padgham, Chuck Ainley, Ed Cherney, producer-engineer-equipment designer, George Massenburg, mastering engineer Bob Ludwig, and John McBride of Blackbird Studios. ATC monitors are also in use at recording studios, soundstages and broadcast facilities, such as East West Studios, Air London, Sony Music Studios, Paramount Studios, Warner Brothers, and BBC UK, to name a few. Even pro audio equipment manufacturers who depend on critical listening for product design depend on ATC, including Shure Microphones and Dolby Laboratories.

ATC Technology:

ATC makes what many consider to be the world’s finest studio monitors, as evidenced by a client list that reads a who’s who of artists, engineers, recording studios, film, post, and broadcast facilities, as well as pro audio manufacturers and educational institutions. Obviously, it takes an attention to fine detail and proprietary technology. Let’s take a closer look at ATC technology.

Linear off-axis response:

To achieve superior loudspeaker performance, there must be a balance between all measured characteristics, including magnitude response, phase response, power response, time domain response, distortion characteristics, and power handling.

Starting with the off-axis response of the loudspeaker, ATC engineers ensure that the phase relationship of the drivers maintain a linear response.

Bass/mid driver soft dome

Soft domes are fixed to the edge of the voice coil, which is 3″ (75mm) in diameter. The dome is designed to decouple from the cone at higher frequencies, where it performs the role of the primary acoustic radiator.

Proprietary soft dome tweeter

In order to maintain the highest levels of performance, ATC controls all aspects of the loudspeaker system to ensure the lowest levels of linear and non-linear distortion. Along with manufacturing their own bass, bass/mid, and midrange drivers, ATC couldn’t rely on OEM or stock designs, and spent considerable time creating a soft dome tweeter to meet their high standards.

Proprietary soft dome tweeter

 In order to maintain the highest levels of performance, ATC controls all aspects of the loudspeaker system to ensure the lowest levels of linear and non-linear distortion. Along with manufacturing their own bass, bass/mid, and midrange drivers, ATC couldn’t rely on OEM or stock designs, and spent considerable time creating a soft dome tweeter to meet their high standards.

Nearly all 1″ (25mm) tweeters use a voice coil suspended in the magnetic gap of the motor immersed in ferro-fluid. The fluid adds mechanical damping, transferring heat to the metalwork and suppressing rocking modes. Over time the fluid starts to thicken presenting resistance to the moving coil assembly, causing the magnitude response to decline.

ATC endeavored to design a tweeter free from the limitation of ferro-fluid while simultaneously overcoming the engineering problems that arise without its use. As with all ATC drivers, the tweeter was approached with optimum performance in mind.

Borrowing the dual suspension technology from their midrange soft dome, which forces the use of a larger voice coil, ATC used extremely large, high-grade neodymium magnets in the motor assemblies to get the required efficiency and top-end extension. ATC also heat-treats the top plate (magnetic annealing) to squeeze that bit extra performance out of the components. Large, well-designed motors mean lots of flux in the gap, which in turn results in extremely low odd-harmonic distortion, an extended magnitude response, and an excellent time-domain characteristic.

Bass/Mid driver construction

ATC drivers feature massive magnet motor assemblies, with no-compromise optimization for each voice coil diameter. Hand-wound voice coils use only high-density, edge-wound, flat OFHC (oxygen-free high thermal conductivity) ribbon copper wire and operate in precision magnetic gaps. Front and rear venting not only reduces airflow noise, but also increases power handling capacity, and therefore, long-term reliability.

Speaker directivity

 The perceived sound quality of a loudspeaker is dependent on its power response, particularly when listening to high-energy transients. As such, high-performance loudspeakers should exhibit a broad and even dispersion with frequency—a factor that ATC takes great care to achieve.

ATC’s largest bass/mid driver is 6.5″ with a crossover of around 2.5kHz, which ATC engineers consider to be a practical limit in a 2-way. In a 2-way system capable of high dynamic range, an ideal crossover point has to be compromised a little to minimize HF driver distortion and increase reliability. If the bass/mid driver was significantly larger, it would become more directional, causing the horizontal response around crossover to suffer. As driver diameter increases to achieve greater bass extension and higher SPL, maintaining good off-axis response would require the move to a three-way system.

Short throat waveguide

ATC tweeters have a carefully designed short-throat waveguide. Deeper throats would affect the balance of the device, both on- and off-frequency, and if taken to the extreme would further increase distortion. At the chosen crossover frequency, ATC’s 25mm tweeter effectively radiates omni-directionally as desired.

In summary

ATC believes that the key to superior performance is designing drivers and systems for use at high levels, and not rigidly adhering to known reference levels for testing. The parameters of drivers vary with level. As such, ATC designs for those changes. Performance at 1W or 90dB SPL is relatively easy, but what happens at 100W or 110dB SPL? ATC knows and designs for it.

The ATC SCM25A Pro grants home and project studio owners entry to the highest level of studio monitors. Talk to your Westlake Pro sales consultant about outfitting your studio with ATC SCM45A Pro 3-way monitors today. 


ATC SCM45A Pro specifications:

  • Drivers: 1″ soft-dome tweeter, 3″ soft-dome midrange, 7″ short-coil carbon paper cone
  • Amplitude Linearity (±2dB): 74Hz-17kHz
  • Cut-off Frequencies (-6dB, free-standing): 47Hz-22kHz
  • Dispersion: ±80° Coherent Horizontal, ±10° Coherent Vertical
  • Max. Continuous SPL (1 meter): 109dB
  • Audio Input: Rear panel mounted female XLR (pin 2 +)
  • Input Sensitivity: 1V RMS (ref. full output)
  • Input Sensitivity Trim: 0dB to -6dB/1V – 2V (continuously variable via rear panel trimmer)
  • Input Impedance: Balanced > 10k ohm
  • Amplifier Output Power: Bass 150W RMS, Mid 60W RMS, High 25W RMS
  • Crossover Frequencies: 380Hz and 3.5Khz
  • Crossover Filters: 4th-order critically damped with phase compensations
  • Low Frequency Boost: 0dB to +3dB at 40Hz (continuously variable via rear panel trimmer)
  • Overload Protection: Active FET momentary gain reduction
  • Dimensions (H x W x D): 10-13/32″ x 16-29/32″ x 14-1/2″ 264 x 430 x 369mm (Handles add 1-1/2″ to depth)
  • Weight: 66 lb. / 30kg (per cabinet)

Additional information

Frequency Response

47Hz – 22kHz










7_, 3"

2 reviews for ATC SCM25A Pro Compact 3-Way Active Monitor

  1. Rated 5 out of 5

    Ryan J

    If you are looking for professional quality, these speakers are well worth the asking price. Try playing your old mixes on these pair of monitors and be prepared to start pulling your hair out from all of the errors you will find while listening. I am able to hear every EQ issue and refine my mixes better than I could with any other studio monitor I’ve ever owned. No small investment, but you won’t be disappointed if you want a professional studio quality sound.

  2. Rated 5 out of 5


    The accuracy and quality really does justify the price. If you’re a pro you can’t afford to go cheap on your monitors. Put your money into good speakers and you’ll never regret it.

Add a review

Your email address will not be published. Required fields are marked *