Impedance Measurement

Impedance Meter

The FX100 Audio Analyzer measures the impedance response of loudspeakers.

This includes small mobile phone transducers, mid-range drivers, tweeters, woofers, large professional audio stacks and distributed audio 70 V / 100 V loudspeaker systems.

At a Glance

  • Short test cycle time
  • Resonance frequency detection
  • Thiele/Small parameters

Loudspeaker Impedance Testing

The tests are executed with a logarithmically swept GlideSweep. This technology ensures very fast, yet precise measurement results. The FX-SIP module with its built-in power amplifier supports the simplest possible wiring.  In order to prevent systematic measurement errors such as cable impedance, a 4-wire connection cable with sense lines is provided.


Measured Parameters

In addition to the impedance response, a wide range of derived or separate results can be calculated or measured, too. Thus, the complete electrical characterization of the device under test (DUT) can be acquired in only one test cycle.

  • Resonance frequencies
  • Thiele/Small parameters
  • DC-resistance

Regular (low impedance) Loudspeakers

Low to medium power devices (mobile phone transducers, consumer audio, multimedia, automotive etc.) are covered by the FX-SIP module. Besides the impedance measurement functionality, it also provides a built-in audio amplifier, thus featuring a very compact and easy-to-use test solution. The FX-SIP module is suitable for speakers up to 30 W into 2 Ω or 4 Ω, or up to 20 W into 8 Ω.

Medium to high power loudspeakers (e.g. Pro-Audio, HiFi) are covered by the FX-SIH module, which can test loudspeakers from 1 W up to >1 kW. The FX-SIH requires an external power amplifier in the test setup.

Example of a mid-range driver impedance response:

70 V /100 V Loudspeakers

Together with the 100 V RT-IB Impedance box, the FX100 can also measure the impedance response of distributed audio 70 V / 100 V loudspeaker systems.

  • For loudspeakers up to 30 kΩ nominal impedance
  • Selectable shunt resistor: 1 Ω, 20 Ω or 400 Ω
  • Impedance response
  • Resonance frequency
  • Impedance at resonance frequency

Example of a 100 V loudspeaker impedance response:


Flexus FX100 Audio Analyzer

Flexus FX100 Audio Analyzer

two channels including FX-Control Suite Software

  • FX-SIP module for < 30 W
  • FX-SIH module for > 30 W
  • 100 V RT-IB impedance box

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