RCF LF21N451 - 3000W 21-inch Neodymium Low-Frequency Driver with 4.5-inch Voice Coil and 8-Ohm Impedance in Black Finish

The RCF LF21N451 is a high-performance 21-inch neodymium low-frequency driver designed to deliver powerful and precise sub-bass frequencies. With an impressive 3000W continuous power handling, this driver is engineered for demanding professional applications where low distortion and minimal power compression are critical. Its advanced design features a 4.5-inch voice coil that improves excursion and linearity at extremely low frequencies, while the proprietary composite pulp cone structure enhances rigidity and overall performance. The LF21N451 also incorporates a dual-forced air ventilation system for efficient cooling, reducing power compression during high output use. This driver is built for those who require robust and accurate low-end reproduction in a variety of sound reinforcement systems.

Specially designed for optimal control and durability, the LF21N451 uses a carbon fibre, nylon, and cellulose composite pulp cone that ensures the driver can withstand large excursions and high-pressure levels without deformation. The dual spider system, constructed with silicon-based damping control, enhances stability, while the triple roll surround further contributes to a smooth and controlled response. The high BL factor of 34.5 T x m provides fast, accurate low-frequency reproduction, making the LF21N451 an ideal choice for subwoofer applications demanding precision and power handling.

For those looking for a robust, efficient sub-bass solution, the LF21N451 offers unmatched performance, with a sensitivity of 98.5 dB and a frequency range extending from 30 Hz to 1000 Hz. Its 21-inch diameter and 4.5-inch copper voice coil combine to produce high-output performance while maintaining minimal flux modulation thanks to its optimized T-pole design. The LF21N451's neodymium magnet structure also ensures that it delivers exceptional power-to-weight performance, making it an outstanding choice for high-power subwoofer systems.

Features

• 3000W continuous program power handling for high output and durability
• 4.5-inch copper voice coil with inside/outside windings for improved excursion and linearity
• 98.5 dB sensitivity for efficient sound reproduction
• 30 Hz to 1000 Hz frequency range for versatile subwoofer applications
• Dual-forced air ventilation system for minimized power compression
• Dual spider design with silicon-based damping control for superior stability
• BL factor of 34.5 T x m for fast and accurate low-frequency reproduction
• Carbon fibre, nylon, and cellulose composite pulp cone for enhanced rigidity
• Triple roll surround design for excellent control at large excursions
• Neodymium magnet structure for reduced weight and improved power handling
• Resonance frequency of 30 Hz and maximum linear excursion of 13 mm for deep bass response
• Optimized T-pole design for minimal flux modulation
• Standard CE compliance for safety

Specifications

General Specifications

• Nominal Diameter: 21 inch / 533 mm
• Rated Impedance: 8 ohm
• Program Power (watt): 3000 W
• Power handling capacity: 1500 W
• Sensitivity: 98.5 dB
• Frequency range: 30 - 1000 Hz
• Effective piston diameter: 470 mm / 18.5 inch
• Max. Excursion Before Damage: 58 mm / 2.28 inch
• Minimum Impedance (ohm): 7.1 ohm
• Voice Coil Diameter: 4.5 inch / 114 mm
• Voice Coil Winding Material: Copper
• Voice Coil Length: 34 mm / 1.34 inch
• Number of layers: 2
• Kind of layers: inside/outside
• Top Plate Thickness: 15 mm / 0.59 inch
• Cone Design: Curved
• Surround Material: Polycotton
• Surround Design: Triple roll
• Magnets: Neodymium
• Dual-force air ventilation: Yes
• Spider: Dual with silicon based damping control

Thiele (small parameters)

• Resonance frequency (Fs): 30 Hz
• DC resistance (Re) (ohm): 5.60 ohm
• Mechanical factor: 6.10 Qms
• Electrical factor: 0.27 Qes
• Total factor: 0.26 Qts
• Bl factor (Bl) (T x m): 34.50 T x m
• Effective moving mass (Mms): 315.0 g
• Equivalent Cas air loaded (Vas): 375.0 liters
• Effective piston area (Sd): 0.170 m2
• Max. linear excursion (Xmax): 13 mm
• Voice coil inductance @ 1kHz (Le1k): 3.00 mH
• Half-space efficency (Eff): 4.00%

Mounting Information

• Overall diameter: 547 mm / 21.54 inches
• Bolt circle diameter: 527 mm / 20.75 inch
• Bolt hole diameter: 7 mm / 0.28 inch
• Front mount baffle cut-out: 512 mm / 20.16 inch
• Rear mount baffle cut-out: 512 mm / 20.16 inch
• Volume occupied by the driver: 6.5 liters / 0.26 ft3

Standard Compliance

• Safety agency: CE compliant

Size/Weight

• Height: 9.8 inches
• Diameter: 21.54 inches
• Weight: 24.03 lbs

Shipping Information

• Package Height: 11.18 inches
• Package Width: 22.99 inches
• Package Depth: 23.78 inches
• Package Weight: 29.76 lbs