Why these drivers?

Criteria for selecting drivers for current-drive

In principle, no special drivers are needed.

Current-drive gives

  • Lower distortion
  • Wider usable bandwidth of drivers
  • Extra dynamics and no power compression

And to exploit this even more, select drivers for

  • Low distortion
    • Low distortion design
    • Non-conducting voice coil formers
    • No ferro fluids
  • Low frequency output
    • Big displacement (Vd)
      • Big diaphragm area (Sd)
      • Big excursion limits (Xmax)
        • Big diaphragm area (Sd) is more important, bigger excursion limits (Xmax) often means that the cone is more heavy, because the (moving) coil is bigger
  • High frequency output
    • Consistent dispersion
    • Smallest diameter: one single round driver per band
    • Smooth response, no or small peaks (for correction)
  • High efficiency
    • Low resonance frequency (fs)
    • Low moving mass (Mms)
    • Big diaphragm area (Sd)
    • Low nominal impedance

Scan-Speak has several lines.The Discovery line, Scan-Speak’s budget line, has the most and best options (Discovery).

For active currents-drive systems the Q of the driver is not critical. But with a very high Q, the resonance frequency needs to be stable for an accurate damping of the resonance. With a current-drive system the impedance curve is easy to measure at the terminals of the amplifier and so the resonance frequency of the driver. And with a digital crossover it is easy to adjust for a shift in resonance frequency. Even an online correction for a shift in resonance frequency is a possibility.