Several of GoldWave's Control visuals convert sounds into a range of frequency bands using a radix-2 fast Fourier transform (FFT) algorithm. When the results are drawn using colours, the graph is referred to as a spectrogram. When the results are drawn with lines, it is often referred to as a frequency spectrum or frequency analysis.

Frequency analysis graphs are displayed in the , , and filter effects. These help you to locate frequencies that you want to remove or enhance.

GoldWave applies a windowing function to the data before performing the FFT (see section). This reduces "discontinuity" errors that occur when dividing data into small chunks. A Kaiser window is used by default.

To make the spectrum more realistic to human hearing, magnitudes are scaled logarithmically. This means that if one frequency "sounds" twice as loud as another, it is graphed with twice the height (or the corresponding colour for the spectrogram).