Model Ultra-high-end midwoofer Diameter 165 mm / 6.50″ Power Handling (RMS/max.) 100 / 160 Watts Impedance 4 Ohms Efficiency 87 dB Frequency Response 45 Hz – 5000 Hz Voice Coil 32,5 mm / 1.28″ Membran Layout Carbon-fleece sandwich Mounting Ø 147 mm / 5.79″ Mounting Depth 67 mm / 2.64″ Resonance Frequency (Fs) 43 Hz