Seas Exel C18EN001/M A low-mass, surface-treated magnesium alloy cone behaves like a piston throughout the audible frequency range, without any sign of midrange resonances. The coaxially mounted magnesium dome tweeter has a low resonance frequency, and integrates with the cone driver to form a point source. The cone profi le has been carefully designed to optimally load the tweeter¿s radiation. A completely new rubber surround reduces resonances and prevents surround break up in the midrange band. The surround¿s small inverted roll, combined with a profi le that follows the shape of the cone, results in almost total elimination of diffraction effects on the tweeter¿s output. The powerful neodymium magnet system, with its small profi le and optimal shape, results in high midrange sensitivity with minimal back wave refl ections. Heavy copper rings mounted above and below the T-shaped pole piece reduce nonlinear and modulation distortion and increase overload margin. The crown-shaped copper tweeter support ring eliminates any resonance coming from the cavity between the tweeter body and midrange voice coil former. All of these features work together to provide a smooth and well behaved off-axis response throughout the entire operating range.