Stiff, yet light aluminum cone and low loss rubber surround show no sign of the familiar 500-1500 Hz cone edge resonance and distortion assosiated with soft cones. Large magnet system gives good transient response, and the bumped back plate together with the very long, and light weight copper clad aluminum voice coil allow for extreme coil excursion with low distortion. Extremely stiff and stable injection moulded metal basket, keeps the critical components in perfect alignment. Large windows in the basket both above and below the spider reduce sound reflection, air flow noise and cavity resonance to a minimum.