FAKE: hard cutoff at 16 kHz. The file was encoded as MP3 before being saved as WAV or AIFF.
macOS audio quality workflow
Fake Lossless Checker for Mac
Scan WAV, AIFF, FLAC, and MP3 files in seconds. Spectro highlights fake lossless tracks before they reach your USB exports.
In short
If a file is an MP3 re-encoded as WAV or FLAC, Spectro detects the spectral cutoff and flags it as FAKE. This detection method is backed by peer-reviewed research (ACM MM&Sec 2009) — 99% accuracy across 2,512 songs.
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Who this is for
- - DJs preparing sets with large mixed-source libraries.
- - Collectors migrating old drives and wanting trusted quality tags.
- - Producers checking downloads before archiving into a master collection.
What Spectro does
- - Batch scan entire folders and get verdicts per track.
- - Classify files as FAKE, MEDIUM, or LOSSLESS with cutoff readout.
- - Apply Finder tags automatically for fast visual sorting.
- - Run fully offline; files never leave your Mac.
How to check your files in under 2 minutes
- 1. Download Spectro and open your music folder.
- 2. Drop files or a full crate into Spectro.
- 3. Review FAKE and MEDIUM results first, then clean or replace.
- 4. Use Finder tags to keep your library organized by quality.
What Spectro detects
Fake lossless files have a hard cutoff in the 16–20 kHz range — the fingerprint of MP3 encoding. Spectro reads this pattern automatically.
LOSSLESS: frequency energy extends to near Nyquist with no artificial cutoff.
Frequently asked questions
How does Spectro know a file is fake lossless?
It analyzes the frequency spectrum of the file and looks for the cutoff fingerprint — the point where high-frequency energy disappears. A WAV file converted from a 128 kbps MP3 will show a hard cutoff around 16 kHz. A genuine lossless recording has energy all the way to Nyquist (22 kHz for 44.1 kHz files).
Can Spectro detect fake FLAC files?
Yes. Spectro checks the spectral content, not only the file extension. A FLAC file transcoded from MP3 will have the same frequency cutoff and will be flagged as FAKE regardless of the container.
What does a MEDIUM verdict mean?
MEDIUM means the file has a higher-quality lossy profile — typically a 256–320 kbps MP3 in a lossless container. It's not a clean lossless file, but the quality degradation is less severe. Spectro gives you the cutoff readout so you can decide whether to replace it.
Are there files Spectro can't classify correctly?
The known ambiguous case is 256 kbps CBR vs. high-quality VBR MP3 — both show a cutoff around 19–20 kHz and are spectrally similar. Spectro flags this explicitly in the diagnosis panel so you can make an informed decision.