RCF LF21X451, Woofer 21", 2000 Watt RMS / 8 Ohm

The LF21X451 low frequency transducer is the result of many years of R&D developments with the goal of creating new levels of professional audio performance standards. This products features advancements and improvements in all the key areas of transducer technology. Incredibly linear frequency response characteristics, the highest power handling of any comparable transducer, the lowest power compression. The LF21X451 features a fibre loaded cone assembly along with a high excursion triple roll, constant geometry surround: this combination provides remarkable strength and a peak to peak maximum excursion of 54 mm. The new dual forced hyper-venting system guarantee a very efficient voice coil ventilation for minimum power compression and incredible power handling.

Features 4,5 - inch fiberglass Inside/Outside copper voice coil 4000 Watt continuous program power handling 97 dB Sensitivity 28 Hz - 1 kHz Frequency range Dual-forced air ventilation for minimum power compression Dual spider designed with silicon based damping control BL of 30.5 Txm to provide a faster and accurate low frequency

General Specifications Nominal Diameter: 530 / 21 mm/inch Rated Impedance: 8 Ohm Program Power: 4000 W AES Power handling capacity: 2000 W AES Sensitivity: 97 dB Frequency Range: 28 Hz ÷ 1000 Hz Effective Piston Diameter: 470 / 18.5 mm/inch Max Excursion Before Damage (peak to peak): 54 / 2.12 mm/inch Minimum Impedance: 6.7 Ohm Voice Coil Diameter: 115 / 4.5 mm/inch Voice Coil Material: Copper Voice Coil Winding Depth: 34 / 1.33 mm/inch Number of layers: 2 Kind of layer: inside / outside Top Plate Thickness: 15 / 0.6 mm/inch Cone Material: No pressed pulp Cone Design: Curved Surround Material: Polycotton Surround Design: Triple roll

Thiele/Small Parameters DC resistance: 5.4 Ohm Mechanical factor: 6.9 Electrical factor: 0.39 Total factor: 0.37 BL Factor: 30.5 T · m Effective Moving Mass: 355 g Equivalent Cas air load: 385 liters Effettive piston area: 0.173 m² Max. linear excursion (mathematical): 13.5 mm Voice - coil inductance @ 1kHz: 2.9 mH Half-space efficiency: 2.2%

Mounting information Overall Diameter: 547 / 21.5 mm/inch Bolt Circle Diameter: 527 / 20.7 mm/inch Bolt Hole Diameter: 6.5 / 0.25 mm/inch Front Mount Baffle Cut-out: 512 / 20.1 mm/inch Rear Mount Baffle Cut-out: 512 / 20.1 mm/inch Depth: 230 / 9.05 mm/inch Volume occupied by the driver: 6.5 / 0.229 liters/ft³ Net Weight: 15.5 / 34.0 kg/lbs