Typical transcode pattern: hard cutoff around 16 kHz and weak upper band.
Rekordbox workflow
Rekordbox Audio Checker for Mac
Check tracks before USB export. Spectro flags fake lossless files so your Rekordbox sets stay consistent on club systems.
Why this matters for Rekordbox users
- - Catch risky files before exporting playlists to USB.
- - Avoid set-break surprises from tracks that look lossless but are transcodes.
- - Prioritize fixes fast with FAKE / MEDIUM / LOSSLESS filters.
- - Keep your preparation workflow private and local on macOS.
What Rekordbox doesn't tell you
Rekordbox reads file metadata: name, BPM, key, duration, and file type as declared in the header. If a file says WAV, Rekordbox treats it as WAV. It has no mechanism for spectral analysis and won't flag a file that was transcoded from MP3 before being saved as WAV.
Spectro reads the actual frequency content of the file — the same information a trained ear would use to evaluate audio quality on a spectrogram. The detection method is backed by peer-reviewed research (D'Alessandro & Shi, ACM MM&Sec 2009) with 99% accuracy across 2,512 songs in a controlled test.
Real-world signal examples
Spectro highlights obvious cutoff behavior and high-frequency continuity, so you can spot transcodes quickly.
Lossless profile: high-frequency energy remains visible near Nyquist.
4-step Rekordbox prep flow
- 1. Build your next-set folder or export candidate playlist.
- 2. Drop that folder into Spectro and run batch scan.
- 3. Filter FAKE and MEDIUM first; replace suspicious files.
- 4. Export only cleaned tracks from Rekordbox to USB.
FAQ
Is Spectro affiliated with Rekordbox or AlphaTheta?
No. Spectro is an independent macOS app that complements your Rekordbox workflow.
Does Spectro modify Rekordbox metadata?
No. Spectro analyzes files and can write Finder tags; your DJ software database remains separate.
Can I use Spectro even if I also use Serato or Traktor?
Yes. Spectro is source-agnostic and works as a quality gate before any DJ software export.
How accurate is Spectro at detecting fake lossless?
Spectro's spectral analysis is based on peer-reviewed research (ACM MM&Sec 2009) that achieved 99% accuracy on transcoding detection across 2,512 songs. The only known ambiguous case is 256 kbps CBR vs. high-quality VBR MP3, which Spectro flags explicitly in the diagnosis panel.
Next step
Run a free batch on your upcoming set files and check how many tracks need replacement before export.
Rekordbox is a trademark of its respective owner. Spectro is independent and not endorsed by or affiliated with Rekordbox/AlphaTheta.