The unison harmony selection is often overlooked, but can be very useful. Adding a unison harmony voice adds more power behind the pitch the singer is using. The extra emphasis to the unison note ends up causing harmony vocals produced by the Vocalist Live 4 in other pitches to create a more subtle effect. Most singers should avoid the pitch corrected unison setting. Listeners are more likely to notice the pitch difference of the singer being slightly off key and a pitch corrected harmony voice than they are to notice the singer and harmony voice both being equally off key.
The first instinct many vocalists have for effects is to set the values so high it is immediately obvious which effects are in use. In some cases, this works for the song, especially for techno, trance and other electronic styles of music. In many cases, subtlety with vocal effects is the best option. The listener may not even pick up on the specific effect in use, but notice the effect adding a little extra to the singer's voice. Try using effects like echo or delay at the lowest settings. You may find it adds a little depth to your voice, even in situations where you normally would not use a vocal effect.
The acoustics in venues can differ substantially from one another. Sound settings that work for an indoor venue might sound odd at an outdoor one. You should test your presets on the Vocalist Live 4 before a show. Have someone stand in the audience and make sure you are getting the intended result. The harmonizer settings should not need to be adjusted. Adjusting the settings on the amplifier it is connected to should fix any issues. Subtle effect usage is most frequently the problem you may have to adjust for. Venues that are purposefully built for music performance allow smaller audio details to reach the audience more easily. Other venues might dampen those details out, requiring you to increase the effects settings until the audience can hear them.