Pseudo-granular synthesis in Reason
Sunday, August 5th, 2007
Granular synthesis is the creation of sound by taking tiny slices of audio from another source and playing them back really quickly. Here’s a handy trick for chopping up samples into pieces without ever leaving Reason. First, create a Redrum drum computer. Next, notice that the function of the bottom left knob in the Redrum varies depending on the channel number. In the third, fourth, and fifth channels, the function is “START”. What this does is alter the starting point in the sound file that you have loaded. So, load up any sound file of your choice (vocal sounds are good) into channel 3, 4 or 5. Then turn Channel 3’s length knob to the left. You want the sound to be just a short burst. Next, while holding Shift, right click (or command click for mac users) on an empty space in the rack. Select “Matrix Pattern Sequencer”. Now, flip the rack around with the Tab key, and then drag a cable from “Gate CV” on the Matrix to “Gate In” on the Redrum. Flip back around again, and then press the Run button on the Matrix. You shuld now hear a stuttering sound. Now play with the Start knob and you will hear the effect we were looking for. Now you can record the automation of the start knob (make sure the Record button next to “Redrum 1″ on the sequencer is lit up red, hit record and then press play). Go wild with the pitch and the start time, and you should get some cool sounds. Even cooler: play with the Resolution knob in the matrix to adjust the speed of gate triggering.

Here’s how to do it in Reason: Create an ECF-42 filter unit, and wire your mixer through the filter into the audio interface. Right click (Ctrl + click for mac) on the device and choose Create Sequencer Track for name of device. When your track is playing, hit record and turn up the FREQ knob to make it sound like you’re going back into the club. Try experimenting with the modes on the filter. BP 12 means band-pass filter. It allows only frequencies a bit lower and a bit higher than the frequency specified by the cutoff point (FREQ knob). The “angle” at which frequency amplitudes drop off is 12dB per octave. The LP filter has two modes: 12 and 24 dB per octave. The 24 cuts off frequencies above the cutoff point much more dramatically then the 12. The 12 leaks more high frequencies than the 24.
In Reason, put a delay device on any drum beat or instrument. Create an automation track for it. Then, make sure that the track’s record toggle button is on. Hit record, and go wild with changing the delay time (the box with numbers in it), feedback, delay unit (ms or steps), etc. If done right, you get a crazy effect because a non-fixed delay time has to compensate for the change by fluctuating the pitch, it’s really weird sounding. Try it!


This involves drawing many sequential ON and OFFs in your volume automation. For an example of this technique, listen to this example from “outer shpongolia” by shpongle. In Reason, there is really simple way to achieve this effect with the matrix pattern sequencer.