The FFT can measure phase angle, but what appears to be a meaningful result might just be the arctangent of a ratio of rounding errors. Throughout this series, we reviewed the fast Fourier transform (FFT) as implemented in Microsoft Excel and investigated windowing functions. In this final part, we’ll cover phase measurements, but first, let’s […]
Audio
Why does the Fourier transform provide apparently inaccurate results, and what can I do about it? part 3
Windowing functions account for mismatches between an input signal and FFT sample size. We concluded part 2 of this series with a look at fast Fourier transforms (FFTs) of 39.1-Hz and 38.12-Hz cosine waves, with our sample size N = 512 and our sample interval Δt = 1 ms (Figure 1). Shouldn’t the amplitudes of […]
Audio analyzer combines analog and digital domains
The APx516B from Audio Precision comes with built-in analog I/O and a slot that adds wired or wireless digital I/O. With so many of today’s devices having audio capabilities, engineeers designing wired or wireless audio into a device need to verify audio quality. Audio Precision, well known for its audio analyzers, has introduced the APx516 […]
