Akai MPC X User Manual page 196

If you set the Assign To field to Make new sample, this
will create a new sample in your project. (The original
sample will remain as it is.)
Use the Pad field to select the desired pad. Alternatively,
press the desired pad.
Check the Crop Sample box to delete the unused
parts from the sample when it's created and assigned.
This feature is destructive, though the project will still
contain your original sample.
Leave this box unchecked to keep the unused parts of
the sample when it is created and assigned. This way,
you will still be able to edit the entire sample further
even though you are using only part of it at the moment.
Use the Program field to specify the program to which
you want to add the slice.
To assign the sample, tap Do It.
To cancel the operation, tap Close, the X, or anywhere
outside the window.
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