27TBC/G is a High Definition metal dome tweeter with a wide, soft polymer surround and a rear chamber. Aluminium/magnesium alloy diaphragm with pistonic behaviour throughout the audible frequency range, resulting in a good dispersion also above 10kHz. A Hexagrid protects the diaphragm, and supports a phase plate which compensates for a slight axial roll off towards 20 kHz. Sonomax surround for low resonance, excellent mechanical linearity and stability without magnetic fluid damping. The voice coil is wound on an aluminium voice coil former with adequate ventilating holes to eliminate noise from internal air flow. The stiff and stable rear chamber with optimal acoustic damping allows the tweeter to be used with moderately low crossover frequencies. The chassis is precision moulded from glass fibre reinforced plastic, and its front design offers optimum radiation conditions.