Four FFGL sources that draw the stereo and surround field as sonar-style displays rather than meters, showing where the energy's pointing, how wide each part of the spectrum is and what the tonal balance looks like. They open their own multichannel capture device, because FFGL gives a plugin nothing but a mono magnitude spectrum and three of the four can't be drawn from that.
This demo runs the plugins' analysis and shaders in your browser, so it needs JavaScript and WebGL2. The plugins themselves, their source and their downloads are on the project page.