crazyoval wrote:I don't understand what exactly 'invert' does,
"Invert" does exactly what it says - it turns the waveform upside down (inverts it)
Everything that is on the plus side of the central line becomes negative, and everything on the lower (negative ) side of the line becomes positive.
Here are two mono tracks. The bottom one is an exact copy of the top track, but it has been "inverted".
If you mix these two tracks together, the result will be silence - a flat line - they will cancel each other out.
crazyoval wrote:So, if I was able to extract the vocal, why was I not able to remove the rest of the track ...
Removing the vocal (simplified):
On the Left channel you have "instruments on the left" + "vocals in the middle"
On the Right channel you have "instruments on the right" + "vocals in the middle"
(any sounds that are in the middle of the stereo mix will come equally from both left and right, giving the impression that they are in the middle)
"subtracting" the right channel from the left you will get:
n the L
eft" + "V
n the M
iddle") minus ("I
n the R
ight" + "V
n the M
as an equation this could be written: (IoL + ViM)-(IoR + ViM)
What you are left with is "instruments on the left" minus "instruments on the right"
(the left channel and right channel vocals have cancelled each other out.)
So the result would be the "left channel instruments" and the inverted
"right channel instruments".
Because "instruments on the left" and "instruments on the right" are different, there is no way to cancel them out.
Note 1: The above explanation is much simplified, but will hopefully give you the idea of how it works.
Note 2: The plug-ins suggested in the earlier posts use other more complicated methods to attempt to isolate vocals and remove all other sounds.