- 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
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.
- General specifications
- Nominal Diameter: 21 inch / 533 mm
- Rated Impedance: 8 ohm
- Program Power: 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
- Minimim Impedance: 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): 5.60 ohm
- Mechanical factor: 6.10 Qms
- Electrical factor (Qes): 0.27 Qes
- Total factor: 0.26 Qts
- BL factor (BL): 34.50 T x m
- Effective moving mass (Mms): 315.0 g
- Equivalent Cas air loaded (Vas): 375.0 liters
- Effettive piston area (Sd): 0.170 m2
- Max. linear excursion (Xmax): 13.0 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
- CE marking: Yes
- Size
- Weight: 10.9 kg / 24.03 lbs
- Height: 249 mm / 9.8 inches
- Diameter: 547 mm / 21.54 inches
- Shipping informations
- Package Width: 584 mm / 22.99 inches
- Package Weight: 13.5 kg / 29.76 lbs
- Package Height: 284 mm / 11.18 inches
- Package Depth: 604 mm / 23.78 inches
