REX’ifying loops with Kontakt

This tutorial will show you how to create “REX” type files in Kontakt. Ever since the REX type file was invented, people have used this technique to more easily reorganize and change static drum loops into something more interesting. All you need is a Drum Loop and Kontakt version 3 or higher.


First, choose a nice drum loop with clear beats. This trick can be done with almost any loop, pitched or not, but it is easiest with drum loops.


  1. Create a new instrument in Kontakt.
  2. Edit the Kontakt instrument by pressing the wrench icon. Now choose the Mapping Editor. This should open a screen which allows you to tell Kontakt which key/keys should playback this loop. I like to assign loops to a really low note like C0.
  3. Now drag your loop from the browser to the mapping editor screen just above the note C0. The closer you get your cursor to the keyboard section, the narrower the note gets assigned to. Since we only want it assigned to the one note, drop it as close as you can to the keyboard.
  4. Now double click the loop region that you just dropped in. This opens your wave editor.
  5. In the Wave editor, choose the Sync/Slice tab, and turn the “grid” on. I like to set my grid to “Auto” which will detect each transient (drum hit) and place a slicing marker just before it. Depending on your loop, you may need to adjust the sensitivity until it looks like each drum hit has a transient marker.
  6. Next you need to grab on the box that says “Drag midi to Host”. This will now export a midi region that will re-trigger the individual loop slices in perfect time. Drag and drop it into the midi track assigned to Kontakt. Once you drag and drop this midi region, Kontakt will place each slice on its own midi note. They do not appear until you drag the midi to your DAW.
  7. Your loop should be playing back normally now. Here is where the fun starts. You can play with the attack, decay, filter, effects, or anything else your heart desires.


The example below is:

4 Bars of the plain loop

4 Bars with pitch bend wheel modifying pitch

4 Bars all segments pitched up 1 octave and decay shortened

4 Bars with a resonant low pass filter being modulated randomly in time

4 Bars of the loop’s midi notes randomized to create new beat

2 Bars with everything pitched up and octave, and played randomly twice as fast.

4 Bars with “Time Machine” on stretching it randomly between 15%-45% and some Squarepusher like repeats.