Alphard DB 418 D1

 Subwoofer 18 inch , VC Size 4 inch    Cone : Paper , Magnet : Ferrite      Voice coil : Copper Clad Aluminum Wire    Surround Material : Foam , Frame : Alu    RMS Power : 3000 W , MAX Power : 6000 W  Impedance : 1+1 / 2+2 Ohm , Mounting Depth : 307 mmCut-out dimensions : 429 mm      SPL @ 1w/1m 90 dB , Fs : 29.4 Hz , Cms : 0.02 m/N  Mms : 666.35 g , Qes : 0.51 , Qms : 6.49    Qts:0.42, BL:26.3, Vas: 175 l, Xmax: 32 mm, Bass Reflex Box: 160LPort Area : 450cm2 , Port Length : 70cm , 30 Hz