Looks like demucs is using a learned filter bank (so no handling of fft phase), and open umix and spleeter are using spectrogram magnitude masking (just reuse p

Looks like demucs is using a learned filter bank (so no handling of fft phase), and open umix and spleeter are using spectrogram magnitude masking (just reuse phase from original fft in all channels). Can't immediately tell what bytedance is doing.