BLASTKING PROFILE21 21-inch High Output Woofer 2000-Watts RMS 4000-Watts Peak 8-Ohms Forced Air Ventilation 5-inch Voice Coil Fiberglass || FEATURES || 5” Voice Coil || 4000 Watts Program Power || 97.2 dB sensitivity || 32 Hz - 1500 Hz frequency response || Forced air ventilation || || SPECIFICATIONS || Nominal Basket Diameter : 533 mm / 21 inch || Rated Impedance : 8 ohm || Rated Power Handling : 2000 Watts || Program Power : 4000 Watts || Sensitivity : 97.2 dB || Frequency Range : 32 hz - 1500 hz || Magnet : 200 Oz / 280x140x25 mm / 11x5.5x1 inch || Minimum Impedance : 5.3 ohm || Voice Coil Diameter : 127 mm / 5 inch || Voice Coil Material : Fiberglass || Voice Coil Length : 25 mm / 1 inch || Number of Layers : 2 || Kind of Layers : inside/outside || Top Plate Thickness : 15 mm / 0.59 inch || || THIELE – SMALL PARAMETERS || Resonance Frequency fs : 32 hz || DC Resistence Re : 35.3 ohm || Mechanical Factor Qms : 35.04 || Electrical Factor Qes : 30.4 || Total Factor Qts : 30.37 || BL Factor BL : 332.4 T – m || Effective Moving Mass Mms : 3278.8 gr || Equivalent Cas Air Load Vas : 3289.6 liters || Effective Piston Area Sd : 30.123 M² || Maximum Linear Excursion Xmax : 39 mm || Half-Space Efficency Eff : 32.2 % || || || MOUNTING INFORMATION || Overall Diameter : 552 mm / 21.73 inch || Bolt Circle Diameter : 527 mm / 20.7 inch || Bolt Hole Diameter : 6.5 mm / 0.25 inch || Front Mount Baffle Cut-Out : 512 mm / 20.16 inch || Rear Mount Baffle Cut-Out : 512 mm / 20.16 inch || Depth : 230 mm / 9.05 inch || || PHYSICAL INFORMATION || Net Weight : 22.8 Kg / 50.3 Lbs || Shipping Weight : 25.4 Kg / 56 Lbs || Dimension (WxDXH) : 610x610x330 mm / 24x24x13 inch || || The BlastKing Profile series brings high output, low frequency woofers in 12”, 15”, 18” and 21” options. These transducers are capable of very low frequencies and are intended for use in a reflex or horn loaded cabinets. They are all made in a high-quality die cast aluminum frame and boast a heavy-duty ferrite magnet that allows for increased power ratings. The Profile transducers are perfect for those needing high level, low frequency output transducers with very low distortion.