27TDC is a High Definition precoated fabric dome tweeter with a wide, soft polymer surround and a rear chamber. Sonotex precoated fabric diaphragm with high consistency and excellent stability against variations in air humidity. 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. 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.