Max Power Rating (Watts): 180 RMS Power Rating (Watts): 50 Compliance (Cms): 662.4 Cone Area (Sd): 15.6 D.C. Coil Resistance (Re): 3.6 Electrical Q (Qes): 1.367 Force Factor (Bl): 3.6 Free Air Resonance (Fs): 56.7 Frequency Response: 52Hz - 21kHz Impedance (Nominal): 4 Mechanical Excursion (mm): 9 Mechanical Q (Qms): 2.248 Sensitivity (dB) (1W/1M): 86 Total Loudspeaker Q (Qts): 0.85 Magnet Structure (Oz): 8