blend in and be less abrupt. To clear up plosive sounds created through vocals a fade-in can be used, but now it has to have a very short time of around 10ms. The fade time can always be adjusted by the engineer in order to locate the best time. It is important that the fade does not change the intelligibility or character of the sound too much. When the crossfade is longer than 10ms the standard linear fades are not always the best choice for music editing. Crossfading A crossfader on a DJ mixer essentially functions like two faders connected side-by-side, but in opposite directions. A crossfader is typically mounted horizontally, so that the DJ can slide the fader from the extreme left (this provides 100% of sound source A) to the extreme right (this provides 100% of sound source B), move the fader to the middle (this is a 50/50 mix of sources A and B), or adjust the fader to any point in between. It allows a DJ to fade one source out while fading another source in at the same time. This is extremely useful when beatmatching two sources of audio (or more, where channels can be mapped to one of the two sides of the crossfader individually) such as phonograph records, compact discs or digital sources. The technique of crossfading is also used in audio engineering as a mixing technique, particularly with instrumental solos. A mix engineer will often record two or more takes of a vocal or instrumental part and create a final version which is a composite of the best passages of these takes by crossfading between each track. In the perfect case, the crossfade would keep a constant output level, an important quality for a club DJ who is creating a seamless mix of dance tracks for dancers or a radio DJ seeking to avoid "dead air" (silence) between songs, an error that can cause listeners to change channels. However, there is no standard on how this should be achieved. There are many software applications that feature virtual crossfades, for instance, burning-software for the recording of audio-CDs. Also many DAW's (Pro Tools, Logic exc.) have this function. Crossfade is normally found on samplers and usually based on velocity. The purpose of a cross-fade it to utilize a smooth changeover between two cut pieces of audio. Velocity crossfading can be incorporated through a MIDI