By PSW Staff • July 21, 2009 The new ACT SCM11, available from TransAudio Group TransAudio Group has announced the immediate availability of ATC’s most reasonably-priced reference monitor, the SCM11 two-way passive speaker. The new monitor incorporates ATC’s Constrained Layer Damping (CLD) technology, which reduces third-harmonic distortion between 100 Hz and 3 kHz, resulting in an extended, resonance-free axial frequency response, improved off-axis frequency response, and a significant increase in loudspeaker power response. The new CLD technology is incorporated in the 5.9 inches (150 mm) mid/low frequency driver with 1.77 inches (45 mm) integral soft dome. The driver features a precision undercut bass pole, in-house, hand-wound precision flat wire coil, and a massive optimized motor assembly. The driver is paired with a new soft dome 0.98 inches (25 mm) neodymium high-frequency unit featuring a precision alloy ATC waveguide. The frequency response of the SCM11 is 56 Hz – 22 kHz (-6 dB), with a sensitivity of 85 dB (1W @ 1 meter) and a maximum SPL of 108 dB. The recommended power amplifier rating is 50 to 300 watts. Finished in black ash, the cabinet dimensions are 14.96 inches (380 mm) (H) by 8.3 inches (211 mm) (W) by 9.84 inches (250 mm) (D). Each unit weighs 18.7 lbs. (8.5 kg). The brainchild of ATC engineer Ben Lilly, Constrained Layer Damping was first introduced in the ATC SCM16A self-powered monitor. Previously, the only way to achieve an extended on-axis frequency response was to use a stiffer driver cone, but the unavoidable tradeoff was a poor off-axis frequency response and a colored sound due to multiple resonances. Traditional designs damp the cone’s motion to reduce these unwanted effects, but the result is a dramatically less efficient loudspeaker. Lilly’s idea was to sandwich a constrained damping layer between two lightweight driver cones. The shear generated when the cone flexes results in less acoustic distortion by instead dissipating unwanted vibration energy as frictional heat. CLD reduces third-harmonic distortion by 10 – 15 dB between 100 Hz and 3 kHz, resulting in a better sounding loudspeaker that requires much less power to generate a given SPL. “ATC’s low distortion technology really works but it’s pricey. This new CLD technology means that small affordable versions of the high-end speakers are now possible. The SCM11 is ATC’s most reasonably-priced loudspeaker to date, and we’re excited to be able to offer this kind of clarity at $1,440 a pair,” says Brad Lunde, president of TransAudio Group. ATC Website Las Vegas Pro Audio Website (a division of TransAudio Group) Comments Have something to say about this PSW content? Leave a comment! Cancel reply Scroll past the ”Post Comment” button below to view any existing comments. Your email address will not be published. Required fields are marked *Comment Name * Email * Website This site uses Akismet to reduce spam. Learn how your comment data is processed. Tagged with: Amplifiers ATC Audio Bass Distortion Drivers Effects Engineer Frequencies Loudspeakers Management Measurement Meters Monitors New Passive Power Reference Articles Sound Technology Transaudio Group Websites Wire · all topics Subscribe to Live Sound International Subscribe to Live Sound International magazine. Stay up-to-date, get the latest pro audio news, products and resources each month with Live Sound.