SPCEIFICATINONS   
Nomin diameter :           457mm. 18in
Nomin al impe dance:    8 ohm
Power rating:                500W RMS                                   
Sensitivity (1w/1m) :     99dB±3dB
Frequency range:          37-2.5KHz
Voice Coil diameter :      φ99.3mm
Voice coil length:           25mm
Air gap height:               12mm
magnet dimension :       φ220mm*25mm

THIELE & SMALL PARAMETERS
Resonace frequency,FS:                37Hz
D.C.Resistan ce,Re:                       5.1 ohm
Mechanical quality factor,Qms:      5.22
Electrical quality factor,Qes:          0.43
Total quality factor,Qts:                 0.39
Equivalent air volme to Cms,Vas:  180L
Mechanical compliance,Cms:          0.13mm/N
Bl factor,Bl:                                    23.81N/A
Effective surface area,Sd：            ㎡

MATERIALS
Basket:                     Aluminium
Cone and dust can : Paper
Surround:                 Treated cloth
Voice coil wire:         Copper
Voice coil bobbin:      Glass Fibre
Magnet:                    Ferrite 

MOUNTING INFORMATION
Overall diameter:         φ460mm
Bolt circle diameter:     φ440mm
Baffle cutout diameter:φ420mm
Depth:                         210mm
Net weight:                 12.2kg