When zones are set up so that their key ranges overlap - completely or partially - you can use velocity switching and crossfading to determine which zones should be played back depending on how hard or soft you play on your MIDI keyboard.
This is done by setting up velocity ranges, with or without crossfading.
Each time you press a key on your MIDI keyboard, a velocity value between 1-127 is sent to Reason. If you press the key softly, a low velocity value is sent and if you press it hard, a high velocity value is sent.
This velocity value determines which samples will be played and which will not.
Let's say for example that you've mapped three different zones across the same key range:
Zone 1 has a velocity range from 1-40.
This means that the sample in it will be triggered by velocity values between 1-40.
Zone 2 has a velocity range of 41-80.
The sample in this zone will be played back by velocity values between 41-80.
Zone 3 has a velocity range of 81-127.
The sample in this zone will be triggered by all velocity values above 80.
Let's change the values above slightly:
Zone 1 has a velocity range from 1-60.
Zone 2 has a velocity range of 41-100.
Zone 3 has a velocity range of 81-127.
Now, velocity values between 41 and 60 will trigger samples from both Zone 1 and Zone 2. Likewise, velocity values between 81 and 100 will trigger sounds from Zone 2 and Zone 3.
You can see which zones have modified velocity ranges in the key map display:
Zones with a full velocity range (0 - 127) are only shown with an outline.
The Edit menu and the NN-XT context menu contain an item called "Sort Zones by Velocity". This option lets you automatically sort the selected zones in the display in descending order according to their set low or high velocity values.
When you invoke this option, the selected zones will be sorted from top to bottom starting with the one with the highest "Lo Vel "value.
Note however, that the sorting is done strictly on a group basis. That is, only zones that belong to the same group can be sorted in relation to each other.
If two zones have the same velocity range, they are sorted by key range.