An adaptive rubber surround provides an ideal match to the cone over the total frequency range. A paper cone with a unique Nextel coating ensures smooth frequency response and low distortion. A large magnet system with bumped back plate, together with a very long and light weight CCAW voice coil allow extreme coil excursion with low distortion and excellent transient response. Heavy copper rings mounted above and below the T-shaped pole piece reduce non linear and modulation distortion and increase overload margin. 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 reflexion, air flow noise and cavity resonance to a minimum.