Another question our users often ask is “how to extract voice from songs ?”, “how can i make an acapella of this song” ? etc.
Vocal isolation is a black science, it’s the voodoo of audio processing… or just a good old spectral substraction !
Free VST Plugins are one of the most exciting things about mixing. In the past it was impossible to imagine that so many quality tools could be available at no cost. Today there are more great free plugins than ever before, but the freeware scene is always changing. The free VST vocal effects plugin gives you the ability to control reverb parameters (pre-delay, space, time, and width), damping (low and high), EQ (lows, mids, and highs), and output gain (both reverb and dry). Ableton Live 9 Intro (VST Plug-Ins) Post by LaunchPON3 » Thu Sep 18, 2014 3:18 am So I bought Intro and upgraded from Lite and I downloaded Launchpad95 and it is the most fun I've had making music.
The principle is basic, find a part of the song without the voice, and substract it from a part with the voice, so you are left with only the voice part. The ideal situation is where you have the normal song (voice + music) and an instrumental version of the same song.
The magic voice isolator plugin exists !! and it’s free.
Kn0ck0ut VST plugin is a free vocal isolation plugin, based on the spectral substracting principle. It takes two inputs : voice+instru on left and instru only on right and it performs a FFT processing for removing the instrumental part. A sort of acapella maker !
Here’s the VST plugin : Best free vst i synthesizers instruments for edm for ableton.
info + download

Now you can download the VST plugin and copy the dll in your VST folder.
If you have the normal song (vocal+instru) and the instumental version :

if you don’t have an instrumental version, you can try to find a part in the song with no vocal, that is similar to the part with vocal.
here’s a test :
voice+instru on left & instru only on right:
https://blog.wavosaur.com/wp-content/uploads/2015/02/feel-the-beat.mp3
after the kn0ck0ut processing for isolating vocal:
https://blog.wavosaur.com/wp-content/uploads/2015/02/feel-the-beat-acapelized.mp3