Amplifier THD+N Sequence
This sequence measures an audio amplifier’s Frequency Response, Gain, THD, THD+Noise, and Self-noise
Introduction
This sequence measures an audio amplifier’s Frequency Response, Gain, THD, THD+Noise, and Self-noise. It accomplishes this by playing a 1/3rd octave sine sweep through the amplifier. A HarmonicTrak™ analysis step calculates the fundamental frequency response curve as well as the distortion plots. The sequence then records and analyzes a spectrum of the amplifier’s self-noise.
Required Software
- 2001 – Spectrum Analyzer (Scope FFT)
Required Hardware
- Audio Interface – Listen AudioConnect or similar
Setup Diagram
Hardware Setup and Calibration
Caution: Before turning on the amplifier make sure that audio interface ground and amplifier ground are connected together or use a balanced connection between the DUT and audio interface.
1. Connect the Output 1 of the audio interface to the left input of the amplifier.
2. Carefully connect the left output of the amplifier to the Input 1 of the audio interface.
3. There is no extra equipment beyond the DUT, so no calibration is required. All input and output calibration values should be set at unity gain for this test (e.g. Direct In 1 and Direct Out 1 Signal Paths).
Get Sequence
This sequence is available in the Sequences folder of your SoundCheck installation.
