19 mm High Fidelity dome tweeter with smooth, extended frequency response. Aluminium diaphragm suspended by a specially designed soft Sonotex surround which allows a low fundamental frequency. Double magnet reduces stray fields around the magnet system and allows the unit to be used in close proximity to a CRT. The double magnet also gives a higher sensitivity. Fine mesh grid protects the diaphragm and carries a phase plate which compensates for a slight axial roll off towards 20 kHz. Voice coil windings immersed in magnetic fluid increase short term power handling capacity and reduce the compression at high power levels.