The LF21N451 is a very high power handling and efficiency transducer specially designed to provide powerful and accurate sub-bass frequencies with low distortion and low power compression.

The height of the voice coil has been specifically designed to improve the excursion and linearity at very low frequencies. The LF21N451 uses a special RCF developed carbon fibre + nylon + cellulose composite pulp which reinforces and improves the rigidity of the cone structure.

The new pulp and the large triple roll surround along double silicon spider system ensure excellent control and makes the cone resistant to deformation caused by very large displacements and pressure created by the transducer’s high excursion behaviour. A fully optimised T-pole design generate the minimum amount of flux modulation. The dual-forced air venting system provides a very efficient voice coil ventilation to minimize the power compression.

Features

4,5 - inch Inside/Outside copper voice coil
3000 Watt continuous program power handling
98.5 dB Sensitivity
30 Hz - 1 kHz Frequency range
Dual-forced air ventilation for minimum power compression
Dual spider designed with silicon based damping control
BL of 34.5 Txm to provide a faster and accurate low frequency

Specifications

Nominal Diameter: 530 / 21 mm/inch
Rated Impedance: 8 Ω
Program Power: 3000 W AES
Power handling capacity: 1500 W AES
Sensitivity: 98.5 dB
Frequency Range: 30 Hz ÷ 1000 Hz
Effective Piston Diameter: 470 / 18.5 mm/inch
Max Excursion Before Damage (peak to peak): 58 / 2.28 mm/inch
Minimum Impedance: 7.1 Ω
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 carbon fiber reinforced
Cone Design: Curved
Surround Material: Polycotton
Surround Design: Triple roll
DC resistance: 5.6Ω
Mechanical factor: 6
Electrical factor: 0.27
Total factor: 0.26
BL Factor: 34.5 T · m
Effective Moving Mass: 315 g
Equivalent Cas air load: 375 liters
Effettive piston area: 0.173 m²
Max. linear excursion (mathematical): 13.2 mm
Voice - coil inductance @ 1kHz: 3.0 mH
Half-space efficiency: 4.0%
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: 250 / 9.8 mm/inch
Volume occupied by the driver: 6.5 / 0.229 liters/ft³
Net Weight: 10.9 / 24 kg/lbs