Features 1.5" KSV voice Coil Neo Charged Ferrite Oxide Enhanced Midbass Wider Frequency Response Paper cone Cloth surround Sold In pairs Specifications Nominal Power Handling: 225 Watts Peak Power Handling: 450 Watts Impedance: 4 Ω Resonant Frequency (fs): 146.1Hz D.C. Voice Coil Resistance (Re): 3.1Ω Mechanical Quality Factor (Qms): 4.94 Electrical Quality Factor (Qes): 0.41 Total Quality Factor (Qts): 0.38 Equivalent Air Volume to Cms (Vas): 3.6 L Cms: 0.10 mm/N Mass of Diaphragm/Coil (Mms): 1