B&C 8NDL51 Drive Unit

• 50 mm (2 in) copper voice coil
• 70 – 3000 Hz response
• 94 dB sensitivity
• Neodymium magnet allows a very light yet powerful motor assembly
• Shorting copper cap for extended HF response
• 400 W continuous program power capacity
• Ventilated voice coil gap for reduced power compression

Specifications

• Nominal Diameter
  200 mm (8 in)
• Nominal Impedance
  8 ohm
• Minimum Impedance
  6.6 ohm
• Nominal Power Handling (AES)
  200 W
• Continuous Power Handling
  400 W
• Sensitivity (1W/1m)
  94 dB
• Frequency Range
  65 - 3000 Hz
• Voice Coil Diameter
  51 mm (2 in)
• Winding Material
  Copper
• Former Material
  Glass Fibre
• Magnet Material
  Neodymium Inside Slug
• Winding Depth
  16.5 mm (0.65 in)
• Magnetic Gap Depth
  8 mm (0.31 in)
• Flux Density
  1.05 T

Parameters

• Fs
  66 Hz
• Re
  5.3 ohm
• Qes
  0.41
• Qms
  3.6
• Qts
  0.37
• Vas
  14 dm³ (0.50 ft³)
• Sd
  220 cm² (34.10 in²)
• η₀
  1 %
• Xmax
  ± 7 mm
• Xvar
  ± 7 mm
• Mms
  28 g
• Bl
  12.4 Txm
• Le
  0.5 mH

Mounting and Shipping info

• Overall Diameter
  225 mm (8.8 in)
• Bolt Circle Diameter
  210 mm (8.3 in)
• Baffle Cutout Diameter
  187 mm (7.4 in)
• Depth
  90 mm (3.5 in)
• Flange and Gasket Thickness
  11 mm (0.4 in)
• Net Weight
  1.8 kg (4 lb)
• Shipping Weight
  2.2 kg (4.8 lb)
• Shipping Box
  300x160x180 mm (11.8x6.3x7.1 in)

Design

• Surround Shape
  Double Roll
• Cone Shape
  Exponential
• Magnet Type
  Neodymium Inside Slug
• Spider
  Single
• Pole Design
  Straight Pole
• Waterproof
  TWP
• Ventilation V.C. Gap
  Yes
• Shorting Copper Cap
  Yes