Using unipolar and bipolar faders

The Electra One fader control has two modes: unipolar and bipolar. These modes determine how negative values are visualized and how the fader behaves when the user interacts with it.

In order to undestand the difference, we need to take a look at how Electra One MIDI and display value ranges work. Detailed info on that can be found at Display and MIDI value ranges.

MIDI values used in MIDI communication are always positive numbers. They range from 0 to 127 for 7-bit messages, or from 0 to 16384 for 14-bit messages. However, the display value range allows us to map these MIDI values to a different range that will be shown on the Electra One screen.

For example, imagine a fader controlling the panning of a sound. The MIDI parameter has a range of 0 to 127, but we might want to display it as -50 to 50. By setting up the fader accordingly, it will appear as a bipolar fader, with -50 on the left, 0 in the center, and 50 on the right. The value indicator will grow either to the left (for negative values) or to the right (for positive values).

However, there are situations where a bipolar fader may not be suitable. Let's say we have a channel fader on a mixing console. The minimum value might be -90, and the maximum value is 4. In this case, using a bipolar fader wouldn't make sense. Instead, we would want an unipolar fader, where the indicator only grows from -90 upwards (to the right).

To summarize, the choice between unipolar and bipolar fader modes depends on the specific scenario. Understanding these modes helps us determine how values are displayed and select the appropriate fader type for different control needs. The preset below demonstrates the differences between the bipolar and unipolar faders. Please note that FADER 1 and FADER 3 operate in the same way, as their value range does not include negative values.