Stream Pro is Delta Sound Labs' granular synthesizer, the full instrument version of the Stream granular effect the US maker first shipped in 2020. Where most popular granular plugins are effects that process whatever you feed them, Stream Pro wants to be the source and the processor at once: it records its own audio, turns it into playable voices, and places the grains in three-dimensional space.
Two modes define it. Single Mode captures, overdubs or replaces audio into a buffer and lets you scrub through it in real time, with bipolar playback from minus two to plus two times and a freeze control for crawling through a sound grain by grain. Multi Mode promotes the engine to an eight-voice polyphonic instrument with per-voice ADSR and stochastic jitter, so a captured texture becomes something you play from the keyboard. On top sits the headline feature: Steam Audio's HRTF spatialization, with BOIDS-style flocking, ping-pong grain distribution and automatable movement paths that turn a flat pad into something that surrounds the listener on headphones.
Four LFOs with 16 routing slots, a Moog-style filter, saturation and a stereo delay fill out the patch, and the instrument is MPE-ready with profiles for Seaboard, GeoShred and Sensel. The caveats are practical: there is no AAX build listed, so Pro Tools users should check first, and the depth here is more than a producer needs for quick granular colour on a track, where an effect like Output Portal is faster. For ambient, cinematic and game audio, though, the capture-and-spatialise workflow is hard to match at 99 dollars. The full first look at Stream Pro covers every mode in detail.