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Version: v4

STEMS Separation Quality

NUO-STEMS 4 features improved STEMS separation algorithms that deliver higher quality results compared to previous versions.

Screenshot

Metric used is called SDR (Signal-to-Distortion Ratio) - read more about it here. And benchmark run results are available here.

Quality Benchmarks​

AlgorithmSDR (Bass)SDR (Drums)SDR (Other)SDR (Instrumental)SDR (Vocals)
mel_vocals_bs_others 14.4413.968.3417.1910.88
bs_roformer 14.4413.878.5417.4511.14
mel_band_roformer (from NUO-STEMS 3.1) 12.3711.666.9217.1510.85
Traktor Pro 4.0.011.5110.605.43---8.07

NUO-STEMS 4 comes with 2 new algorithms:

  • mel_vocals_bs_others (Recommended)
    • Vocals: Processed with Mel-Band-RoFormer (that was first introduced in NUO-STEMS 3.1)
    • Drums, Bass & Other: Processed with BS-RoFormer
    • Provides amazing quality, especially for vocals
    • Algorithm link
  • bs_roformer
    • New algorithm introduced in NUO-STEMS 4
    • Provides great quality for all stems
    • Vocals quality is similar to 'mel_vocals_bs_others'
    • Feel free to experiment and compare with 'mel_vocals_bs_others' - sometimes one or another brings better results
    • Algorithm link

All the algorithms in NUO-STEMS are open source and available on GitHub (click links above).

Hearing comparisons​

There are a lot of comparisons between different programs (Serato, Traktor Pro, RekordBox, etc.) available in this YouTube playlist