ATC began building custom units in 1974, mainly a range of 12” drivers for the PA industry. ATC introduced the 12″ PA75-314 driver, a design capable of handling more power and producing less distortion at a higher sound pressure level than any other unit on the market. As bands like Supertramp began to use these drivers in live rigs, ATC began to gain recognition. Roughly a year later, ATC launched a 3-inch soft dome midrange with better dispersion, wider bandwidth, and lower distortion. The driver, known as the SM 75-150, became a mainstay in the product line, boasting a wide frequency range, high power handling, and neutral sound characteristics. Today, the SM 75-150 is installed in several 3-way models from the SCM-40 up to the SCM-300.
ATC founder Billy Woodman emphasized the importance of using quality midrange drivers when the company started. For ATC, the performance of its loudspeakers depends on an accurate midrange; performance is never compromised in this area. In the late ‘90s, Billy Woodman and his research team developed an innovative new driver topology designed to eliminate the effects of magnetic hysteresis as a significant source of distortion in loudspeaker drive units. For better efficiency, the back plate, pole, magnet, and front plate are magnetized as a singular unit, as opposed to magnetizing each individual component. All ATC drivers are made using fine materials such as pure copper wire with high-temperature enamel for unquestionable reliability at extreme power levels.