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

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.

Part number:

11100092
LF21X451

Specifications
General specifications
Nominal Diameter
21 inch / 533 mm
Rated Impedance
8 ohm
Program Power (watt)
4000 W
Power handling capacity
2000 W
Sensitivity
97.0 dB
Frequency range
28 - 1000 Hz
Effective piston diameter
470 mm / 18.5 inch
Max. Excursion Before Damage
54 mm / 2.13 inch
Minimum Impedance (ohm)
6.7 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
Ceramic
Dual-force air ventilation
Yes
Spider
03
Thiele - small parameters
Resonance frequency (Fs)
28 Hz
DC resistance (Re) (ohm)
5.40 ohm
Mechanical factor
6.90 Qms
Electrical factor
0.39 Qes
Total factor
0.37 Qts
Bl factor (Bl) (T x m)
30.50 T x m
Effective moving mass (Mms)
355.0 g
Equivalent Cas air loaded (Vas)
385.0 liters
Effective piston area (Sd)
0.170 m2
Max. linear excursion (Xmax)
14 mm
Voice coil inductance @ 1kHz (Le1k)
2.90 mH
Half-space efficency (Eff)
2.20%
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
245 mm / 9.65 inches
Diameter
547 mm / 21.54 inches
Weight
15.5 kg / 34.17 lbs
Shipping information
Package Height
284 mm / 11.18 inches
Package Width
584 mm / 22.99 inches
Package Depth
604 mm / 23.78 inches
Package Weight
18.5 kg / 40.79 lbs
Downloads
SPECIFICATIONS
PDF
462 KB
19-08-2024
PDF
61 KB
11-07-2024
DRAWINGS
PDF
395 KB
21-03-2018
ZIP
3.8 MB
22-01-2024
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