Spek

To tell if downloaded music is truly lossless or frequency-capped, listening isn't enough. Spek shows it: a free acoustic spectrum analyser that draws audio as a spectrogram to reveal bitrate and frequency cutoffs.

Features

Spectrum Analysis: View audio spectrograms.

Quality Check: Spot bitrate and cutoffs.

Many Formats: Broad format support.

Open Source: Cross-platform, free.