the best method?

First of all, you’re gonna need these 3 programs. Fruity Loops, Zero-X Beatslicer,Knockout (VST Plugin)
along with this template file for fruity loops

This works best with CD rips. Vinyl works sometimes, but not as much as CD and not nearly as clean, It gives off white noise among other unwanted frequencies.

Step 1:

Load wave files (both instrumental and vocal versions) in Zero-X Beatslicer. Zoom in on both files, and find the first downbeat or any other noticeable spot that you can easily match in both files.

Step 2:

Next, you’re going to need cut out the excess audio to the left of the point you want both files to start. Select the excess audio, then go to Edit, and Cut. Do this with both files, so they both start at the exact same point. Afterwards, save both files.

Step 3:

Open the acapella template file in Fruity Loops. Make sure the Knockout VST loads automatically when you open the template file.

Step 4:

Load the vocal version in the top slot, and the instrumental version on the bottom. Click the play button. There should be a significant difference in the volume of the beat. If not, then play with “Input Gain” or either amping up the volume of the instrumental (Channel Settings, Misc tab). Sometimes this causes the vocal level to fluctuate and other times it works smoothly. I guess it all depends on the rip and how the tracks were mastered.

Step 5:

When extracting the acapella pay attention to the length of the wave files. When you go to export audio, the output length may be shorter or longer than the length of the original wave files. To extend the output length or decrease it…adjust the tempo.

WOrd up.

4b) To install the Knockout plugin.

download and unzip the .rar file, then drag the plugin onto the desktop.

Open this folder:

C:\Program Files\Image-Line\FLStudio5\Plugins\VST

drag the file into the folder.

Open fruity loops, Then go to the Channels Menu>Add One>More….

in the box that pops up, you should see a refresh button at the bottom. click it then choose fast scan. Now look for Kn0ck0ut in the VST plugins section and place a check next to it. exit fruity loops and then restart fruity loops.

5) go to File>Templates> acapella_template (or whatever you named it).

You should see boxes that say “vocals” and “instrumental”. A box should also pop up that says “Kn0ck0ut (FX 2)” if you do not see the “kn0ck0ut” box, make sure you did step 4b right.

6) Right Click the red “Vocals” box, and click “load sample”. go to the File of the actual song that you rendered in acid and click open.

then right click the “Instrumental” box and do the same thing except go to the instrumental file you rendered.

Now, Click Play. you should hear some of the beat, but mostly the acapella. play around with the two knobs by the boxes and the knobs on the “kn0ck0ut” plugin until you get the best sound.

7) Go to file>export>MP3 file. name it whatever you wanna name it and then click save. a box should pop up. set the bit rate, then uncheck the boxes in the “options” category. now click start.