Akai MPC 5000 Reference Manual page 126

The larger the value you set, the more drastic a change you can make to a sample by how hard you hit the pad.
Refer to 'Filter Envelope' on page 110 about the other parameters in the Filter Envelope window.
„
You can set any number except OFF.
You must set the same number to activate the mute group.
Hit one pad while playing back another. The first sample will be stopped and only the sample of the pad you hit will by played.
„
The MPC5000 overlaps the sound in the program. (Polyphony)
The MPC5000 does not overlap the sound in the program. (Monophony)
„
The Sample page will be displayed.
The MPC5000 overlaps the sound.
The MPC5000 does not overlap the sound. If you select MONO, when you hit the pad several times, only the last pad that was hit will
be played.