Open the track you want to extract the acapella from (I picked Everyday People by Sly & the Family Stone ; by the way, don't try to make an acapella out of it, the result is pretty poor although the pictures can't tell you that)
[img]http://frenchpella.free.fr/images/tuto/DIYacap01.png[/img]
Click on "Center Channel Extraction" (the mouse cursor is right on the icon)
Of course, I saved my standard presets (acapella & instrumental), you can use it or get inspired by it or by the Acapella & Vocal Remove original presets.
In the Granularity & Resolution zone, push every parameter at its maximum (even if it's gonna take more time), FFT Size & Inlays. As I got inspired by original presets, I kept the discrimination parameters as such. The central channel can go to 48 dB however, my twisted mind made me stay at 36 dB.
You can also easily create an instrumental by removing the central channel, in fact it's cleaner than acapella extraction (check my boot You Know these Boots are Getting Smaller for a good example) and no treatment is required after that.
Click OK.
It's gonna take some time as you can see.
[img]http://frenchpella.free.fr/images/tuto/DIYacap04.png[/img]
Now you obtain a "thinned down" sound, we got rid of quite a lot of stereo elements.
Except that we still have parasite background sounds, something left from the drums in general.
[img]http://frenchpella.free.fr/images/tuto/DIYacap05.png[/img]
Select the biggest portion you can take from the background noise without vocals (the longer the better) and click on "Reduce Background Noise".
Put the FFT Size at its maximum (24000) as well as the number of "captions" (4000) and click on the "Capture the profile". Close the window, select the part where you want to reduce the noise (normally the all track except if it changes radically).
Click again on "Reduce Background Noise". REduce the noise by 12 dB (not more or you take risk to get important parasite distortions). Put the same values you see on the picture for the other parameters, they're well-tested. You can also read Audition Help Files to use other values or try to understand what you're doing. Click OK. Repeat this step if you need to clean another part of the sound.
After that, choose the channel where the acapella quality is noticeably better (here, the left side but they're pretty close in general, if you're not sure, choose the quieter channel of the two, the one where there were no drums)
[img]http://frenchpella.free.fr/images/tuto/DIYacap07.png[/img]
Click F11 (Convert sample type), Mono, 100% into the channel you chose, and 0% in the other one. Click OK.
Now you can save your dirty pretty acapella and use it into a mashup or whatever you like (you can, before you do that, put it into Ableton Live to set the tempo constant).














