Stereo Widening

Although the principle is quite old, ‘widening' of the sound image is still done these days in many portable devices, ghettoblasters and PC loudspeakers, even though it is usually called something else in these applications. To generate the stereo image, the left channel also contains part of the sound from the right channel, shifted a little in phase compared to the right channel. The same is true for the right channel, where the signal from the left channel is slightly shifted in phase. To make the stereo image ‘wider’, you can amplify the difference signals of both channels.