Specification :

SPECIFICATION
Nominal Basket Diameter 18 " , 457.2mm
Nominal Impedance* 8 ohms
Power Rating
Watts 1250W
Music Program 2500W
Resonance 32Hz
Usable Frequency Range 33Hz-300Hz
Sensitivity* * * 95.8
Magnet Weight 109 oz.
Gap Height 0.375 " , 9.53mm
Voice Coil Diameter 4 " , 101.6mm

THIELE & SMALL PARAMETERS
Resonant Frequency ( fs) 32Hz
DC Resistance ( Re) 5.07
Coil Inductance ( Le) 1.59mH
Mechanical Q ( Qms) 10.15
Electromagnetic Q ( Qes) .49
Total Q ( Qts) 0.47
Compliance Equivalent Volume ( Vas) 331.5 liters / 11.7 cu.ft.
Peak Diaphragm Displacement Volume ( Vd) 1159cc
Mechanical Compliance of Suspension ( Cms) 0.18mm/ N
BL Product ( BL) 17.2 T-M
Diaphram Mass inc. Airload ( Mms) 143.17 grams
Efficiency Bandwidth Product ( EBP) 64.9
Maximum Linear Excursion ( Xmax) 10.0mm
Surface Area of Cone ( Sd) 1159.0 cm2
Maximum Mechanical Limit ( Xlim) 19.2mm

MOUNTING INFORMATION
Recommended Enclosure
Sealed 104.8-172.7 liters/ 3.7-6.1cu.ft.
Vented 118.9-303 liters/ 4.2-10.7cu.ft.
Overall Diameter 18 " , 457.2mm
Baffle Hole Diameter 16.56 " , 420.6mm
Front Sealing Gasket Fitted as standard
Rear Sealing Gasket Fitted as standard
Mounting Holes Diameter 0.28 " , 7.1mm
Mounting Holes B.C. D. 17.25 " , 438.2mm
Depth 8.15 " , 207mm
Net Weight 27.4 lbs., 12.4 kg
Shipping Weight 30.9 lbs., 14 kg

MATERIALS OF CONSTRUCTION
Coil Construction Copper voice coil
Coil Former Kapton
Magnet Composition Ferrite magnet
Core Details Extended core with Core Periphery Ventilation
Basket Materials Die-cast aluminum basket
Cone Composition Treated Paper-Kevlar
Cone Edge Composition Cloth cone edge
Dustcap Composition Porous cloth top spider/ heatsink