Download Gonio3:

Advanced Stero Analysis:

The Gonio3 VST plugin by uk-music is an Audio Vector Oscilloscope (Goniometer), presenting a detailed picture of the stereo output of your audio signal. An Audio Vector Oscilloscope lets you check the mono compatibility of a recordingby displaying how much of the audio signal that passes through the left and right channel, and how much is present in the mid and the side signal respectively. The Gonio3 VST effect also features aphase meter to test for phase differences between the two stereo channels of the audio signal.