Continuous power handling
Voice coil diameter
Diaphragm material
Throat diameter
The Helical Approach

B&C has a reputation for performance, by turning the limits of traditional compression driver design on their head. HLX™ : Compression driver efficiency in miniature. The HLX™ phase plug (US and EP Patents Pending) has a central channel that is twisted, like DNA, to gain the length required to match the outer channels. This technique works with standard, cost-effective injection mold tooling and plastics by rotating the inner die along a screw profile. The convex dome design, so achieved, has a number of significant cost and performance advantages.

Minimized diameter, weight, and cost
lncreased diaphragm area
 Low, ~1kHz Crossover point
 Reduced distortion, especially intermodulation distortion
 More efficient magnetic flux use



  • Ultra Compact 48mm diameter
  • 40 W continuous program power capacity
  • 1" horn throat diameter
  • 36 mm (1.4 in) aluminium voice coil
  • HT Polymer diaphragm
  • 1000 - 17000 Hz response
  • 108 dB sensitivity


  • Throat Diameter25 mm (1.0 in)
  • Nominal Impedance4 Ω
  • Minimum Impedance4.1 Ω
  • Nominal Power Handling220 W
  • Continuous power handling340 W
  • Sensitivity (1W/1m)4108.0 dB
  • Frequency Range1.0 - 17.0 kHz
  • Recommended Crossover51.0 kHz
  • Voice Coil Diameter36 mm (1.4 in)
  • Winding MaterialAluminium
  • Inductance0.06 mH
  • Diaphragm MaterialHT Polymer
  • Flux Density1.8 T
  • Magnet MaterialNeodymium Inside Slug

Mounting and Shipping Info

  • Two M5 holes 180° on 53 mm (2.09 in) diameter.
  • Diameter is 64mm at widest point (driver rotated, across mounting studs).
  • Overall Diameter48 mm (1.89 in)
  • Depth46 mm (1.81 in)
  • Net Weight0.25 kg (0.56 lb)
  • Other DetailsOne M5 threaded hole on the back of the magnet structure is available for the installation of an optional heat sink. Diameter is 69mm at widest point (driver rotated, across connection tabs).
  • Driver mounted on B&C ME 45 horn.
  • 2 hour test made with continuous pink noise signal within the range from the recommended crossover frequency to 20 kHz. Power calculated on rated minimum impedance.
  • Power on Continuous Program is defined as 3 dB greater than the Nominal rating.
  • Applied RMS Voltage is set to 2 V for 4 ohms Nominal Impedance.
  • 12 dB/oct. or higher slope high-pass filter.