Description
ATC SCM50A Pro 3-way active midfield monitor features a 12.4″ super linear bass driver, 3″ super dome mid driver, 1″ dual-suspension tweeter with ATC’s 350-watt tri-amp pack
The ACM50A Pro is an active 3-way midfield monitor system designed for medium-sized control rooms. The ACM50A comes with a 9″ custom ATC Super Linear bass driver, and features ATC’s proprietary 1″ dual-suspension tweeter, and SM751505 midrange soft dome driver. The SCM50A Pro is a reference-quality monitor providing exceptional stereo imaging and detail. It has six MOS-FET amp blocks matched to the drivers for optimal performance, with loads of transient headroom and maximum SPLs of up to 112dB. A low-frequency contour control offers five bass boost settings and a flat reference.
ATC SCM50A Pro 3-way midfield monitor in one take:
- ATC 1″ dual-suspension ‘S-Spec’ tweeter
- Full “SL” Super Linear 9″ bass driver
- ATC 3″ “Super Dome” mid driver
- Onboard grounded source, 350W ATC tri-amp pack
- LF contour control
- Clip indicator
- 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.
Whether you’re mixing for film or commercial music, the detail and spectacular imaging of the ATC ACM50A Pro will make your mix jump out of any speaker as you intended. Talk to your Westlake Pro sales consultant about outfitting your studio with ATC SCM50A Pro 3-way monitors today.
ATC SMC50A Pro specifications:
Drivers: HF 1″/25mm, Mid 3″/75mm, LF 9″/234mm
Amplitude linearity (±2dB): 70Hz-17kHz
Cutoff frequencies (-6dB, free-standing): 32Hz, 22kHz
Horizontal dispersion: ±80°, Coherent
Vertical dispersion: ±10°, Coherent
Max. Continuous SPL (1 meter): 112dB
Crossover Frequencies: 380Hz, 3.5kHz
Input Connectors: Male XLR
Input Sensitivity: 1V
Input Sensitivity Trim: 0dB to -6dB/1V – 2V (continuously variable via rear panel trimmer)
Input Impedance: Balanced > 10k ohm
Amplifier Output: Bass 200W, Mid 100W, High 50W Filters : Even Order Critically Damped
Overload Protection: Active FET momentary gain reduction plus thermal tweeter protection
Front Panel Indicators: Power On indicator, Gain Reduction warning
LF EQ: 0dB to+6dB @ 40Hz (continuously variable via rear panel trimmer)
Dimensions (HxWxD): 716 x 351 x 400mm (28-3/16˝ x 13-13/16˝ x 18-13/16˝) Depth with amplifier at rear adds 3˝
Weight: 107.8 lb. / 49kg