Reduce Vocals
Use this effect to reduce vocals in music. In some stereo recordings it is possible to remove vocals by subtracting the left and right channels. In order for this to work perfectly, vocals must be identical (recorded equally) on both the left and right channels. If there is any stereo echo or reverb applied to the recording, vocals cannot be removed completely.
Note that any instruments recorded equally on both channels will be removed along with the vocals. This is unavoidable.
Usually subtracting the left and right channels destroys the stereo sound, giving mono output. However, by integrating a bandstop filter, GoldWave is able to restore some of the stereo, enhancing the output. Try the Reduced vocals with more stereo preset. Bring the From and To filter values closer together for increased stereo (increases the vocals) or farther apart for reduced stereo (decreases the vocals).