Open Ambience Project has released SHEPPi (Stereo Haas Effect Ping Pong Inverter), a free spatial enhancer effect plug-in for Windows PC.
What SHEPPi describes is this. You set up a ping-pong delay with feedback of around 30mS, which is the sweet spot for the well-known Haas stereo widening effect. Then, in one of the crossfeed delay lines you put an inverter such that the artificial early reflections are bouncing around out of phase (exaggerating the wideness) and out of time with each other. Bob adds some extra control over this effect by determining whether the delay feedback (“Deep” switch) or single-channel crossfeed inverter (“Wide” switch) should be on or off. In addition, the K-Stereo process adds a couple of convenience touches easily simulated with other tools: an M/S matrix processor (also known as a “shuffler”) preceding the effect, and a post-effect EQ module for tailoring the synthetic reflections.
Open Ambience Project’s SHEPPi Spatial Enhancer plugin (VST, Windows) does all of this. You can even use the plugin on an aux bus instead of the more typical track insert because SHEPPi gives you full control over the dry signal that’s usually mixed in.
SHEPPi is available as a free VST effect plug-in for Windows PC, released under the Creative Commons Attribution-Noncommercial-Share Alike 3.0 Unported License.
More information: Open Ambience Project