Featuring the new ATC designed and built 25mm soft dome tweeter, updated bass/mid drivers and crossovers housed in a curved, laminated cabinet, the new range of ATC closed-box passive loudspeakers has arrived. Along with the smaller SCM7, SCM11 and SCM19, the SCM40 is the first to employ ATC's landmark SH25-76 tweeter, developed to satisfy the company's long-established rigour in drive unit engineering.
Sharing technology with the renowned ATC soft domed mid-range drive unit, the new SH25-76 tweeter employs a unique dual suspension system suppressing rocking modes even at high power output levels. The ATC configuration of a short edge-wound voice coil in a long, narrow magnetic gap ensures exceptionally low distortion throughout its operating band and removes the need for ferrofluids, which can dry out over time, compromising performance.
"The bottom line.. I’m sold. I can’t live without them. I need them in my life and will have to make the change." — HiFi Wigwam
A complex, shaped, soft-domed diaphragm extends high frequency range and offers a smooth off-axis response. The tweeter's 15,000 gauss (1.5 tesla) neodymium magnet has a black heat-treated top plate, which dissipates heat away from the voice coil to maintain high power handling and low power compression. A precision-machined 5.5mm rigid alloy waveguide provides optimum dispersion, a flat on-axis frequency response and resonance-free operation.
Establishing what is to be a new style for ATC's most competitively priced range of loudspeakers, the new SCM40 benefits acoustically and aesthetically from a curved cabinet construction. Braced and laminated for high rigidity and damping, the curved enclosures in real cherry or black ash veneer also impart a strong impression of design quality. Improved crossovers featuring metallised polypropylene capacitors, large air cored inductors and ceramic wire-round resistors offer superior power handling and clarity. The SCM40 exhibits an impedance curve free from low values, presenting an easy load for amplifiers of 75 to 300 watts. The SCM40 is designed for optimum performance without the grille - although a full-length perforated metal grille, finished in anthracite grey to match the drive unit face plates, is supplied. According to tradition, each model number represents internal cabinet volume in litres.
The new SCM40 features ATC’s new SH25-76 tweeter with a ATC’s renowned 75mm/3” Soft Dome mid-range and a 164mm, short coil – long gap (underhung) bass driver. The three-way design and inclusion of the Soft Dome mid results in excellent clarity, even at high drive levels with bass heavy souce material. It also gives wide, even dispersion resulting in excellent stereo imaging and un-fussy positioning in the home. The new model also benefits from crossover revisions that have improved the loudspeakers overall balance and the integration between mid and high frequency elements.