• RCF LF21X451 21" SPEAKER HANDLES A MASSIVE 2,000 WATTS AES, 4,000 WATTS PROGRAM POWER HANDLING
• LARGE 4.5" FIBERGLASS INSIDE/OUTSIDE COPPER VOICE COIL & TRIPLE ROLL SURROUND FOR INCREASED CONTROL
• EXTENDED XMAX OF 13.5MM WITH A HIGH BL FACTOR OF 30.5 TM FOR A FAST TIGHT ACCURATE BASS
• DUAL SPIDER & DUAL FORCED AIR VENTILATION FOR MINIMUM COMPRESSION
• VERY HIGH X DAMAGE OF 54MM
• CARBON FIBER REINFORCED CONE FOR INCREASED DURABILITY IN HORN LOADED CABINETS
• WORKS WELL IN HORN LOADED OR PORTED HIGH POWER SUBWOOFER SPEAKER SYSTEMS

WOOFER MODEL	LF21X451
SPECIFICATIONS
Nominal Basket Diameter	21"
Impedance	8 ohms
AES Power Rating	2,000 Watts
Program Power	4,000 Watts
Frequency Response	28Hz - 1.0kHz
Sensitivity (1W/1m)	97dB
Voice Coil Diameter	4.5" / 5mm
Max. Excursion Before Damage	2.28" / 115mm
Voice Coil Winding Depth	1.3" / 34mm
Number Of Layers	2
Kind Of Layer	Inside/Outside
MATERIALS
Cone Material	No Pressed Pulp-Carbon Fiber Reinforced
Cone Design	Curved
Voice Coil Material	Copper
Diaphragm Material	Paper Pulp
Surround Material	Polycotton
Surround Design	Triple Roll
Magnet	Ferrite
MOUNTING INFORMATION
Overall Diameter	21.5" / 547mm
Bolt Circle Diameter	20.7" / 527mm
Baffle Cutout Diameter	20.1" / 512mm
No. Of Mounting Holes	8
Mounting Hole Diameter	0.25" / 6.5mm
Overall Depth	9.05" / 230mm
Flange Thickness	.6" / 15mm
Volume Displaced By Driver	6.5 Liters / .229ft^3
Net Weight	15.5 kg. / 34 lbs.
Shipping Weight	17.59 kg. / 38.7 lbs.
THIELE-SMALL PARAMETERS
Resonant Frequency (fs)	30 Hz
Impedance (Re)	5.4 ohms
Coil Inductance (Le)	3.0mH
Electromagnetic Q (Qes)	.39
Mechanical Q (Qms)	6.9
Total Q (Qts)	.37
BL Factor	30.5TM
Moving Mass (Mms)	355 grams
Compliance Equivalent Vol. (Vas)	385 liters/13.59cu. ft.
Voice Coil Overhang (Xmax)	13.5mm
Surface Area Of Cone	.173m2
Reference Efficiency	2.2%
FREQUENCY RESPONSE
IMPEDANCE CURVE
MOUNTING INFORMATION

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