RCF LF21X451 21-inch, 4000W, 8 Ohm Bass Woofer

Product specifications

• nominal diameter: 21"/533mm
• nominal impedance: 8 Ohms
• program power: 4,000W
• output capacity: 2,000W
• sensitivity: 97.0dB
• frequency range: 28Hz - 1000Hz
• effective piston diameter: 470mm/18.5"
• max. damage excursion: 54mm/2.13"
• minimum impedance: 6.7
• voice-coil diameter: 4.5"/114mm
• voice-coil material: copper
• voice-coil length: 34mm/1.34"
• number of layers: 2
• layer sort: interior, exterior
• upper plate depth: 15mm (0.59")
• cone design: curved
• surround material: polycotton
• surround design: three-double role
• magnet: ceramic
• air ventilation with double power: yes
• spin: double with silicon based damping treatment

• resonant frequency (Fs): 28 Hz
• DC impedance (Re): 5.40 Ohms
• mechanical factor: 6.90 Qms
• electrical factor: 0.39 Qes
• total factor: 0.37 Qts
• Bl-factor (Bl): 30.50 T x M
• effective moving mass (Mms): 355.0g
• equivalent Cas air-loaded (Vas): 385.0 litres
• effective piston surface (Sd): 0.170 m2
• max. linear excursion (Xmax): 14mm
• voice-coil induction @ 1kHz (Le1k): 2.90 mH
• efficient at half space (Eff): 2.20%

• total diameter: 547mm / 21.54"
• bolt circle diameter: 527mm / 20.75"
• bolt hole diameter: 7mm
• front mount bulkhead recess: 512mm / 20.16"
• rear mount bulkhead recess: 512mm / 20.16"
• driver volume: 6.5 litres / 0.26 ft3

• dimensions (diameter x height): 54.7 x 24.5cm
• weight: 15.5 kg