KORG PA4X 76 - Manual (Page 465)

Making new sounds with Sampling |461
Protecting the loop length
▪ Use the Loop Lock to fix the length of the loop being edited. When it is
closed, moving the Loop Start automatically moves the Loop/Sample End
point, or vice versa.
This is convenient when you are creating a rhythm loop to match a specific
tempo.
Using crossfade looping
When looping the pitched sample of a complex sound such as strings or
woodwinds to make the sound sustain, it is necessary to create a long loop
to preserve the rich character of the sound. Crossfade Loop can be used to
minimize the difference in pitch and level between the beginning and ending
of the loop region, to create a natural-sounding loop. In order to solve such
problems, Crossfade Loop causes the sound to change gradually from the
end to the beginning of the loop.
In practice, here is how it works. A specific length (the Crossfade Length
value) of the waveform immediately before the beginning of the loop is taken
and mixed with the end portion. At this time, the waveform level of the por-
tion immediately before the end (the length specified by Crossfade Length)
will gradually decrease, and the waveform level immediately before the be-
ginning of the loop will gradually increase as the two are mixed.
When the
Loop On checkbox is selected, and the Start and Loop S(tart)
parameters have different values, the Crossfade button becomes available.
1 Touch the Crossfade button to open the Crossfade Loop dialog:
2 Use the Crossfade Length parameter to specify the length of the sample
that you wish to crossfade. You can enter it either as the number of samples,
or a percentage (%). If you set this as a percentage, the number of samples
will be calculated automatically.
If you set this to 50%, crossfade will be performed on the second half of the
region between loop start and loop end.
The Crossfade Length cannot be greater than the smaller length between
the Sample Start – Loop Start points, or the Loop Start – Sample End points.