someone needs to explain, what is inverting?

Where do we begin…..

U need a decent sample editor, a high quality original of the track (usually CD) and an instrumental of the very same track (usually CD).. I say CD to ensure the best quality acapella produced, although u can use vinyl n MP3s with varying results. I say varying results due to the very nature of electro-mechanical playback of vinyl producing minutely inconsistant speeds (which will make a difference) and the nature of compression of the MP3 format.

So lets assume we’re using CDs.. DO NOT SAMPLE the tracks, digitally extract the audio (nearly all sample editors of decent quality can do that) so u end up with 2 perfect copies of each track.

So u have 2 tracks loaded into a sample editor..

U flip/invert/phase invert the instrumental and MIX it with the original which cancels the music out and leaves the acapella..

I’ll try to explain this in a mathematical sense… imagine music having 16 settings of volume 0-15.. now if your music begins loud at say 12 and dips and i’ll add a few more values… starting at 12 and continuing with 10,9,8,7,4,2,1… to visualise that it would look like something sloping down high to low..

NOW..

If u added those same values to an inverted wave (which would slope upwards), which values would read -12,-10,-9,-8,-7,-4,-2,-1… now lets do the maths (or math)

12,10,9,8,7,4,2,1 (for the original track) and -12,-10,-9,-8,-7,-4,-2,-1 (for the instrumental track)

-12 + 12 = 0
-10 + 10 = 0
-9 + 9 = 0
-8 + 8 = 0
-7 + 7 = 0
-4 + 4 = 0
-2 + 2 = 0
-1 + 1 = 0

The musical values are cancelling each other out..

Now imagine that on a bigger scale 44.1khz 16bit samples (from CD) where the original n INVERTED instrumental have been precisely lined up, ur gonna get music cancelling music with plus and minus values and u get left with a sample where the music is cancelled out to leave u with the vocals (the acapella)

I hope this makes sense to someone and helps someone in their quest for DIY acapellas

DeviantDreamer wrote:

Wow. Impressive. Never seen this method before. I didnt think math could play such a role in audio! So by ‘inverting’ the instrumental, do u mean like, reversing the audio?

Inverting the audio is different to reversing..

REVERSING

Think of it as the word ‘HELLO’, now place a theorectical mirror to the left or right hand side of the word and u get a mirror image of the word spelt ‘OLLEH’ but obviously the letters are the other way around.. this is REVERSING..

INVERTING

Imagine the the word ‘WOW’, place a mirror above or below it and you get the word ‘MOM’… This is INVERTING..

A perfectly lined up Original and INVERTED Instrumental shall cancel out the music and leave you with the acapella..

Hope this has made a little more sense and helped