Divide MP3 into single voices

[SubK]

Have you tried this one already?

https://www.bandlab.com/splitter

Today our conductor demonstrated the abilities of this nice little (free) feature. Really great for listen to certain details, transcribe, reahearse etc.

Cheers

[ryebrye]

I loaded it up but I don't see where it can extract different parts from an mp3

It looks like a decent multi track recording app though

[Matt K]

A lot of times, professionally mixed tracks are, at least, in stereo, so you isolating the tracks is functionally like splitting out the various parts. It looks like they might do some magic ontop of that to isolate the four categories of things they highlight: drums, vocals, bass, and "other". I don't think it gives the ability to say, isolate the individual instruments, etc.

[ghmerrill]

I looked into this sort of thing several years ago because I wanted to separate the high tuba and low tuba parts on the Earl/Fosi "Sears Advanced Duets" CD so I could play one of the parts while the other played on the CD.

Fosi told me this wasn't possible because they hadn't recorded the parts on separate tracks, and that Earl had done all the recording stuff. You can't separate was isn't separable.

On the other hand, pretty much anything is theoretically separable. I can imagine a heavy-duty AI program that would be able to accomplish such a separation. But I don't know if anyone has actually created an application like that at this time. I'm not about to try.

[JohnL]

I'd be curious as to how this works. I know the old way of eliminating vocals was to invert one of the stereo channels and then sum them (this works because the vocal is usually dead center on the stereo "stage". I suppose if you wanted to eliminate everything but the vocal, you could have software that compared the two channels and removed anything that wasn't equal or near equal in both. Once you're got the vocal isolated, you could invert it and add it back into the original stereo tracks.

For drums, I'd look for the sharp peaks. Basically a refinement of depopping software. Once you've eliminated the drums from the original tracks, you invert those tracks and add them back in to cancel out everything but the drums.

With bass, I'd start with whatever was left over after eliminating the vocals and the drums. Run it through a low pass filter and you're most of the way there to isolation. Inverting and adding the isolated tracks back into the original tracks will eliminate it.

Once you've eliminated the vocal, drums, and bass, you've got the "other" signal, which can be inverted and added back in if you want to eliminate those parts.

Now if you want to separate out individual parts played by like instruments? That's way above my pay grade.

[harrisonreed]

A lot of times, professionally mixed tracks are, at least, in stereo, so you isolating the tracks is functionally like splitting out the various parts.

A track being in stereo vs mono doesn't have much to do with isolating the individual instruments or tracks used to make the recording. Once you sum to stereo, the tracks for each instrument are effectively hard coded together into a single stereo (or mono) track.

Stereo tracks might be tricker for different softwares to isolate instruments in if the stereo is from a spaced pair, because you'd effectively have two versions of one instrument offset by a few milliseconds, combined into each of the two channels (assuming it wasn't hard panned, with the left and right channels blended 70/30 30/70 or whatever).

I think the current ways of doing it are like JohnL is describing, where you use phase inversion to isolate stuff, but done automatically in the software. Other plugins like iZotope RX Rebalance use a spectrum analyzer and input from the user to identify each instrument's "spectral signature" and then the software can block out the rest of the track. It's already tuned for pop groups so you can just turn up bass or turn down the drums with sliders without even having to do any thinking.

The Splitter plugin from the OP looks a lot like the iZotope one, but specifically for pop groups only.

[Matt K]

That makes sense, I was under the impression that it was more common to keep the channels isolated in the mix, which is why you can pan "L" and "R" on a lot of albums and totally remove things like vocals. Actually, now that I say that... why does removing one of the channels often do that if the mix is well, more of a mix where voices are blended into both "sides"?

[harrisonreed]

That makes sense, I was under the impression that it was more common to keep the channels isolated in the mix, which is why you can pan "L" and "R" on a lot of albums and totally remove things like vocals. Actually, now that I say that... why does removing one of the channels often do that if the mix is well, more of a mix where voices are blended into both "sides"?

The only thing I've heard of where you can do that is the old piano accompaniment discs, where you would mute either left or right track to isolate the piano from the example solo track. But that was by design.

Vocals are usually dead center in the mix, and the track will be a mono recording. The other instruments are panned 40/60, 20/80, whatever, depending on what side of the stage you want them on. Because you're panning mono signals in a pop track, you get the illusion of stereo, but it's going to be mono compatible, if played on a mall speaker or phone, for example.

It would sound weird if the singer was only on one side of your car!

[robcat2075]

The website says ANY song. Several months I used an online AI tool like that to remove background music from a narration, it was all on one mono track - no stereo tricks possible, and the result was pretty good.

The vocal-only wasn't 100% clean but... 98% maybe. Good enough.

If you solo any of the tracks in the demo at the site the OP listed, you will hear some quiet swish-swish background noise. That suggests to me that it is indeed extracting the tracks as claimed as best it can and that it is not a rigged demo where each track was recorded individually.

Would it be able to pull out each Trombone separately from a big band record?

Probably not... yet.