When Crossfade is selected, SoundReplacer crossfades between replacement audio files in different amplitude zones. This helps smooth the transition between them.When Crossfade is deselected, SoundReplacer hard switches between replacement audio files in different amplitude zones.Crossfading is particularly useful for adding a sense of realism to drum replacement. Crossfading between a straight snare hit and a rim shot, for example, results in a much more “live” feel than simply hard switching between the two samples.