I wanted to share a simple and effective application of NMF for creating a fake stereo enhancement or up-mix.
My source is a gritty crackle composed from concatenating some raw-data samples together. I wanted to gradually create a separation of the heavily monophonic sound as if it were ‘bisecting’. This was really easy and effective using nmf.
From the command line I nmfed my sound source into two components.
I then replaced the original mono source in my reaper project with my new stereo file. Using the ‘width’ control in reaper I automated this to go from 0 -> 100% over the specified duration for increasing the stereo-ness of the sound.
That’s my kind of music <3 (ah, it seems that discourse does not have the heart emoji shortcut)
To try to tackle the phasiness, have you tried other fft settings? another idea would be to m/s funnel mix, aka low mid in mono, top in stereo, simply done with MS-encode -> high-pass the S -> MS-decode. Playing with the freq of the HP is a fun and creative thing