Fi Car Audio BTL4 18 D2

2x1Ω
2x2Ω

Subwoofer

Nominal diameter18″ / 470 mm
Resonance25 Hz
Q factor0.52
Sensitivity88.1 dB
Linear excursion± 33 mm
Program Power7000 W
mm05101520101001 00010 000Diaphragm ExcursionMaximum Linear Excursion
m/s0246810101001 00010 000Diaphragm Velocity
dB60708090100110120101001 00010 000SPL (1W, 1m, on axis)Maximum SPL
°-180-120-60060120180101001 00010 000Acoustical phase (1m, on axis)
ms051015202530101001 00010 000Group Delay (1m, on axis)
Driver
Port
Combined
Frequency response
Hz
Impedance
Ω
Impedance Phase
°
Excursion
mm
Velocity
m/s
SPL
dB
Acoustical Phase
°
Group Delay
ms
Transient response
ms
Discard
Apply
  • Sensitivity (1W, 1m, infinite baffle) SPL1W 88.1dB

Thiele & Small parameters

  • Resonance frequency (free air) fS 25Hz
  • Mechanical quality factor QMS 7.59
  • Electrical quality factor QES 0.55
  • Total quality factor QTS 0.52

Large signal parameters

  • Maximum linear excursion xmax 33mm
  • Air volume displaced at xmax VD 3993cm³
  • Power handling P 3500W
  • Program power Pmax 7000W

Voice Coil

  • Nominal impedance Z 2 x 2Ω
  • DC resistance (in series) RE 2.8Ω
  • Inductance (1kHz, in series, estimated) LE 4.16mH

Magnet

  • Force factor (in series) Bl 20.2N/A
  • Motor constant Bl/√RE 12.1N/√W

Diaphragm

  • Effective diameter 393mm
  • Effective area SD 1210cm²
  • Moving mass MMS 554g
  • Moving mass (without air load) MMD 524g

Suspensions

  • Stiffness KMS 13.7N/mm
  • Compliance CMS 73µm/N
  • Equivalent volume to the compliance VAS 151L
  • Mechanical resistance RMS 11.5N·s/m

Dimensions

  • Nominal diameter 18
  • 470mm
  • Overall diameter 470mm
  • Baffle cutout diameter 425mm
  • Mounting depth 241mm
  • Volume occupied by the driver 2.83L
Ω°0102030405060101001 00010 000-180-120-60060120180Electrical ImpedanceElectrical Phase
00.51-205101520Step response
-1-0.500.51-2010203040Response to a tone burst of Hz with cycles


Similar subwoofers to Fi Car Audio BTL4 18 D2

Fi Car Audio BTL4 18 D1 Subwoofer

Fi Car Audio BTL4 18 D1

2 x 1 Ω
18 Subwoofer
fS24.8 Hz
SD1210 cm²
QTS0.53
xmax33 mm
SPL1W88.3 dB
Bl/√RE12.1
Pmax7000 W