frequency spectrum


I am plotting a frequency spectrum with Audacity. I have noticed that when I change the Size command, also the spectrum changes. Could you explain me what this option is?

Thank you

“Plot Spectrum” uses FFT analysis to split the sound into lots of frequency bands, and then plots a graph to indicate the amplitude in each frequency band. Points between each of the distinct frequencies are plotted by interpolating between the points on the graph (it draws a smooth curve from one point on the graph to the next. The “Size” setting determines the number of frequency bands. The larger the “size”, the more frequency bands there are, and the narrower each band is. Thus a large “Size” will show more detail, but the level in each band is likely to be lower because each band is catching fewer frequencies.

There is additional information in the manual: