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 !
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 :
KnockOut VST
Kn0ck0ut VST
Now you can download the VST plugin and copy the dll in your VST folder.
How to isolate vocals / get the vocal out of the song :
If you have the normal song (vocal+instru) and the instumental version :
- 1. open Wavosaur
- 2. menu Files->Open and select the files to load (one song file + instrumental file)
- 3. if the files are stereo, for each file unselect left channel ( press the “1” key), select all (CTRL + A) and use menu -> Process -> Mute : this mutes the right channel
- 4. on the instrumental file, use menu->Process->Swap channels
- 5. use copy / cut / paste to select the part you want to “extract” and try to make the two files “in sync” the best you can (use zoom in in time & amplitude for more precision)
- 6. select all (CTRL + A) the instrumental part and copy (CTRL + C)
- 7. select all the normal part and use menu->Edit->Paste special-> Paste and mix
- 8. open VST rack, load KnockOut VST plugin, and open the plugin UI
- 9. use the “R input gain” to find the right balance between vocal isolation and overall quality : the more you increase the parameter, the more the vocal is isolated, but the effect is more drastic and you can clearly hear the artefacts of the spectral processing
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:
after the kn0ck0ut processing for isolating vocal:
hey, cool article i will try it 😀 do you know the song from the example and the artist maybe ? sounds good! ty
The song in the example is 2 Static Feat. Nasty Cat – Feel That Beat
good old eurodance
Its not working on my adobr audition cc!
Why?
Does this work for mac?
here’s the knockout linux version : https://github.com/jeremysalwen/kn0ck0ut-lv2
it’s open source, you can port it to Mac
Wouldn’t it be enough to just do a phase inversion on one of the audio files and then do a mono mixdown ?
Since the phase inverted signal will cancel the other one out , the vocal is left over .
No need for fft
i haven’t found yet an instrumental that can phase-cancel with the normal version.
even if you find an instrumental with perfect time matching (with one-sample precision!), there are poor chances that it works : the voice is -quasi- never mixed “as is” with the rest of the mixdown, there is dynamic compression involved => the levels does not match
To produce great separation results without instrumental version of the song take a look at Audionamix software. They released Trax and Trax pro standalone software which extraxts automatically vocals from any song. The final quality depends on the source, but in most of the cases is really great! With Trax Pro it is possible to apply spectral edditing if you want to have cleanest track. I am using it in my projects… It is also possible to extract other melodic content, like instrumental parts… Check it out at http://www.audionamix.com
Can not install on ableton live 9 64 bit for windows, the program does not recognize it
The plugin is 32 bit
it may work with a bridge.
But this is not the kind of plugin to use in a sequencer like Ableton Live.
nice
Working on all songs! That’s a good vst plugin! And if vocals in the song is not on the left, follow these steps:
1. Remove Right Channel Of The Song
2. Import Instrumental Version
3. Remove The Left Channel Of The Instrumental
4. Mix and render
why is the kn0ck0ut plugin heard from 1 left side