Celestion CF1840JD 18" Subwoofer w/Ferrite Magnet - 8 ohm - Open Box

• Balanced airflow venting provides enhanced cooling
• Twin demodulation rings
• Optimised double suspension
• Nominal diameter : 457mm / 18in
• Power rating : 1200W
• Continuous power rating : 2400W
• Rated impedance : 8Ω
• Sensitivity : 97dB
• Frequency range : 30-2500Hz
• Chassis type : Cast aluminium
• Magnet type : Ferrite
• Magnet weight : 3.18kg / 112oz
• Voice coil diameter : 100mm / 4in
• Voice coil material : Round copper
• Former material : Glass fibre
• Cone material : Kevlar loaded paper
• Surround material : Cloth-sealed
• Suspension : Double
• Gap height (Hg) : 10mm / 0.39in
• VC winding height (Hvc) : 30mm / 1.18in
• Additional impedances : 4Ω

Parameters

• Sd : 1134.12cm2 / 175.79in2
• Fs : 37.00Hz
• Mms : 217.40g / 7.67oz
• Qms : 4.372
• Qes : 0.437
• Qts : 0.397
• Re : 5.29Ω
• Vas : 155l / 5.47ft3
• BI : 24.76Tm
• Cms : 0.09mm/N
• Rms : 11.56kg/s
• Le (at 1kHz) : 1.16mH
• Xmax : 12.5mm / 0.49in

Mounting Information

• Overall diameter : 460mm / 18.11in
• Overall depth : 220mm / 8.7in
• Cut-out diameter : 414mm / 16.24in
• Mounting hole dimensions : 11x7mm / 0.43x0.28in
• Number of mounting holes : 8
• Mounting hole PCD : 441-432mm / 17.36-17.01in

Frequency Response and Impedance Curves

• Power rating : Tested for two hours using a continuous, band-limited pink noise signal as per AES standard. Power calculated on minimum impedance. Loudspeaker tested in free air.
• Continuous power rating : Defined as 3dB greater than the AES rating.
• Sensitivity : Measured on axis at 1W, 1m in 2π anechoic environment.
• Parameters : Measured after unit subjected to pre-conditioning signal.
• Xmax : 0.5*(Hvc-Hg) + 0.25*Hg