Using Tone on a muddy vocal
When doubling a vocal that is either characteristically thick and intimate or overly boxy and muddy, you may find that the VoxDoubler emphasises the timbre too much. By increasing the Tone control, a subtle EQ is applied to counteract the build-up of low frequencies.
Using Tone on a bright, sibilant vocal
When doubling a vocal that is either characteristically bright and airy or overly harsh and sibilant, you may find that the VoxDoubler emphasises this timbre too much. By decreasing the Tone control, a subtle EQ is applied to counteract the build-up of high frequencies.
Using Tone to change the character of the doubles
As well as using the Tone in a corrective fashion, it's also useful for changing the character of the new voice(s). For example, increasing the Tone setting can increase the clarity and quality of diction, helping your VoxDoubler to cut through the mix without having to raise the overall level.
It is also possible to dull the character of the VoxDoubler by decreasing the Tone setting. Doing this will add an extra depth and warmth to the vocal whilst subduing the clarity, which can help to avoid a cluttered sounding track.