SPCEIFICATINONS   
Nomin diameter :           457mm. 18in
Nomin al impe dance:    8 ohm
Power rating:                300W RM S                                   
Sensitivity (1w/1m) :     98dB±3dB
Frequency range:          28-200KHz
Voice Coil diameter :      φ75.5mm
Voice coil length:           19mm
Air gap height:               10mm
magnet dimension :       φ190mm*20mm

THIELE & SMALL PARAMETERS
Resonace frequency,FS:                28Hz
D.C.Resistan ce,Re:                       6.5 ohm
Mechanical quality factor,Qms:      13.75
Electrical quality factor,Qes:          0.36
Total quality factor,Qts:                 0.35
Equivalent air volme to Cms,Vas:  391L
Mechanical compliance,Cms:          0.18mm/N
Bl factor,Bl:                                    22.4N/A
Effective surface area,Sd：            0.125㎡

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

MOUNTING INFORMATION
Overall diameter:         φ459mm
Bolt circle diameter:     φ444mm
Baffle cutout diameter:φ419mm
Depth:                         204mm
Net weight:                 8.5kg