Frequency response describes how a system changes amplitude and phase with frequency. VA coordinates generation and acquisition to produce curves for amplifiers, filters, loudspeakers, microphones and audio chains.

Measurement principle

The system is excited with a known signal and VA compares input with output. Measurements may be performed point by point, with a sweep or using wide-band signals, depending on the method and the device.

  • Amplitude curves in dB
  • Channel comparison
  • Measurement-chain compensation
  • Curve saving and overlay
  • Use with amplifiers, filters and acoustic systems
  • Integration with generator and analyser
Calibration matters Audio interface, cables, attenuators, microphone and room can all modify the curve. Reliable work requires characterising or compensating the chain and separating device response from the test system.

Electro-acoustic measurements

With loudspeakers and microphones, room, distance, reflections and noise become part of the result. Sweeps and time-domain analysis can help distinguish the direct response from room effects.

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Read more in the Visual Analyser Handbook

This page is an operational introduction. Chapter 5 — Frequency response of the forthcoming book covers theory, controls, algorithms, examples and measurement notes in much greater depth.