The modulation matrix is the true brain of version 1.1.15. Where other synths hide routing behind menus, Spire offers a spreadsheet-like grid visible in the lower half of the interface. This transparency allows sound designers to map almost any parameter to an envelope, LFO, or velocity source instantly. The "Random" modulation source, unique to Spire at the time, allowed for unpredictable, living pads that breathed with algorithmic variation.
In v1.1.15, the is particularly snappy. You can route the step sequencer to the filter cutoff to create trance gates directly inside the synth, saving CPU on external volume shapers like LFOTool or Kickstart. Vst Plugin Spire-x64-v1.1.15 -vsti-