As we discussed in last week’s tutorial, granular synthesis is something quite remarkable. In terms of creating a different sound than the original input, it is unmatchable. If you want to create lush textures, soundscapes, mind-bending delays, and more, granular synthesis is capable of delivering all of that and much more.

The previous part of this tutorial was aimed to show you the Portal’s main user interface coupled with some practical audio examples. In this part, we will deal more with what’s “under the hood”. We already made a couple of audio channels in our SoundBridge: DAW – a vocal, drum loop and an electric piano. So let’s begin!



We talked before about the main interface of the Portal. However, by clicking on the icon marked in red in the picture above, a new menu opens with much more sophisticated controls and a lot more things going on.



As you can see, the upper part of the interface we are talking about is offering a variety of controls. So, let’s try to explore it one by one.

In the top left corner, we can see a knob for stretching the audio and just below the retrigger, which can be set to the beat (¼, ⅛. 1/16, and so on). Furthermore, on the right from that, we can see a grain section which contains several parameters essential for the excellent “granular” sound.


Grain controls


The grain controls of Portal are where most of the sound processing happens. Incoming audio is sampled into an audio buffer and is then sliced into tiny pieces called grains. You can stretch, overlap, delay, pan, smooth pr reverse the grains using STRETCH, SPEED, REVERSE, PITCH, PAN, OFFSET, SHAPE, DENSITY, GRAIN SIZE, TIME, and FEEDBACK controls.

Below this, we have the modulation section, which is made up of two assignable clickable envelopes.



You can click to add nodes. Moreover, double click to remove nodes. Additionally, click and drag to move nodes. Finally, click and drag lines between nodes to change curve. Assign MODULATION by dragging and dropping colored MODULATION indicators ( + ) onto a knob. Set MODULATION DEPTH by clicking and dragging on the MODULATION circle beside the assigned knob. Furthermore, right-click on a MODULATION circle to change MODULATION to BIPOLAR, UNIPOLAR, or to REMOVE MODULATION. Also, right-click a knob to RESET to default, and remove all MODULATION. MODULATION takes on the current knob position as the zero points of modulation. Change the zero position for MODULATION DEPTH depth by shift + click and dragging up or down on the assigned MODULATION circle.





Lastly, if we click on the “EFFECTS” section on the bottom right, we can use a variety of different effects such as Bit Crusher, Chorus, Distortion, Filter, Phaser, Reverb, and Stereo delay. The EFFECTS section of Portal consists of two EFFECTS which run in series after the Granulator. The EFFECTS section, therefore, consists of POST GRANULATOR DRY / WET and PRE MASTER DRY / WET. This allows for EFFECTS such as reverb to be applied to both the granulated, and non-granulated signal.


Audio examples


So, let’s hear a couple of audio examples in the end.


~Vocal – Unprocessed

~Vocal – Processed with Portal

~Drum Loop – Unprocessed

~Drum Loop – Processed with Portal

~El. Piano – Unprocessed

~El. Piano – Processed with Portal


Feel free to download the project here.