Plugin to do stereo widening with decorrelation.
Stereo widening widens the perception of the stereo image by boosting the surrounds and lowering the mid/side ratio. This plugin has controls for the stereo width in lower and higher frequencies, with a controllable cutoff frequency. The filterbank consists of a lowpass and highpass in cascade, which can be energy preserving (Butterworth, default), or amplitude preserving (Linkwitz-Riley). Two options for decorrelation are available -- efficient convolution with velvet noise filters (default), or a cascade of allpass filters with randomised phases. A transient handling block ensures that transients are not smeared by the decorrelating filters.
Use the installer included with the release. The next time you restart your DAW the plugin should show up under the developer name orchi.
The details of this plugin are outlined in the paper An open source stereo widening plugin - Orchisama Das in Proc. of International Conference on Digital Audio Effects, DAFx 2024.