SPCEIFICATINONS   
Nomin diameter :           457mm. 18in
Nomin al impe dance:    8 ohm
Power rating:                500W RMS  
Sensitivity (1w/1m) :     98dB±3dB
Frequency range:          40-2KHz
Voice Coil diameter :      φ99.3mm
Voice coil length:           25mm
Air gap height:               15mm

THIELE & SMALL PARAMETERS
Resonace frequency,FS:                40Hz
D.C.Resistan ce,Re:                       6.2 ohm
Mechanical quality factor,Qms:      3.82
Electrical quality factor,Qes:          0.39
Total quality factor,Qts:                 0.35
Equivalent air volme to Cms,Vas:  188L
Mechanical compliance,Cms:          0.08mm/N
Bl factor,Bl:                                    28.16N/A
Effective surface area,Sd：            0.132㎡

MATERIALS
Basket:                     Aluminium
Cone and dust can : Paper
Surround:                 Treated cloth
Voice coil wire:         Al ribbon
Voice coil bobbin:      Aluminium
Magnet:                    Ferrite 

MOUNTING INFORMATION
Overall diameter:         φ474mm
Bolt circle diameter:     φ448mm
Baffle cutout diameter:φ426mm
Depth:                         211mm
Net weight:                 18kg