ARC SUBWOOFERS, Are you looking for a sub that can not only get loud but sound great doing it as well? Than the ARC Series Subwoofer is just what your looking for. This accurate driver can fit in an extremely small enclosure, leaving your trunk empty enough to still use! Feel the chest pounding bass from this natural sounding low frequency transducer! One piece molded rubber surround, High temp black anodized voice coil, Progressive flat spider, Extended bump plate, Features: Impedance: 2 or 8 ohm, Resonant frequency: 25Hz, Sensitivity: 87db, RMS power handling: 250 watts, Electrical "Q": .365, Mechanical "Q": 5.12, Total "Q": .341, Equivalent volume: 2.25, One way linear: 15mm, Mounting depth: 5.5", Optimum sealed enclosure: .65 cuft, Ported enclosure: .9 cuft, ARC10D4 - ARC Audio 10" 250 Watt Dual 4 Ohm Subwoofer