How to spot a fake WAV or FLAC with a spectrogram
Updated October 17, 2026
In shortA fake lossless file is an MP3 converted to WAV, AIFF or FLAC. It is big but keeps the original MP3's cutoff. On a spectrogram, a real file reaches 20 to 22 kHz; a fake one stops sharply around 16 kHz (128 kbps), 19 kHz (192 kbps) or 20 kHz (320 kbps).
The landmarks to know
- Sharp cutoff around 16 kHz: 128 kbps MP3 source.
- Around 19 kHz: 192 kbps source; around 20 kHz: 320 kbps.
- A real 44.1 kHz master goes up to about 22 kHz, with an uneven top end.
How to check
- Drop the file in the free DJWavPool analyser: it gives the verdict directly.
- Or open it in Spek, free on Windows and Mac, and see where the spectrum stops.
- Check files found outside stores and official promos first.
Misleading cases
- Some masters are deliberately filtered above 18 kHz: see whether the cutoff is sharp or gradual.
- Old recordings and digitised vinyl naturally have fewer highs.
- When in doubt, ask the artist or label for the file.
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