YouTuber/producer Hainbach and developer Bram Bos have announced the release of Fluss, a granular synthesizer and effects processor for iOS that's said to be inspired by experimental composer Iannis Xenakis.
The app, which runs standalone on iOS or as an AUv3 plugin, enables the user to manipulate tiny grains of audio in a variety of complex ways, using a "kinetic" control interface that's geared towards live performance and realtime sonic manipulation.
Under Fluss's hood is a 3-voice grain engine, which is capable of processing three sound sources independently. Each grain engine can be controlled via its own playhead in the centre of the app's interface, while two XY pads give users control over scan speed, panning, pitch, glide, and more.
Both the XY pads and the three central sliders are powered by a physics model that allows the user to flick and throw them around using the touchscreen. The dots in the XY pads will bounce around like balls, reacting to a degree of virtual friction that the user can dial in themselves. This is a unique alternative to the traditional LFO that opens up some interesting modulation possibilities.
As for sound sources, the user can drag and drop WAV files into Fluss, record audio directly, or process incoming input live. There's an extensive preset library featuring recordings of some rare and unusual instruments from Hainbach's collection, including a "1940s Ondioline, a forgotten East German piano, and Nagra-treated percussion".
Fluss is equipped with a unique multi-mode filter that's been modelled on the Oberheim Xpander, and a Shimmer feedback effect that feeds processed audio back into the grain engine to produce a shimmering reverb-like sound that can be applied with subtlety or pushed into experimental territory to create endless loops.
The app's also capable of some pretty advanced pitch quantization, a feature absent from many popular granular synth plugins. Fluss pitch-shifts its output by default, according to a variety of scales and modes determined by the user, making it easier to integrate the results into a song or composition harmonically.