Postfader

Postfader is a term used in audio mixing to describe a routing option for sends and effects where the level sent from a channel to a bus or effect is taken from the signal after the channel’s fader. In practice, this means the send level tracks the fader: lowering the fader also reduces the amount sent to the destination, and raising it increases it. This is in contrast to a pre-fader send, which taps the signal before the fader, so changes to the fader do not affect the sent level.

Postfader routing is commonly used for time-based effects such as reverb and delay on individual channels, so the effect level follows the channel’s overall level as you mix. It is also used for parallel processing paths that should ride with the main mix, such as a compression or ambience bus that needs the same fader response as the source. In contrast, pre-fader sends are preferred for cue monitoring or for feeds that must remain constant regardless of the channel fader position.

In modern digital audio workstations and many hardware consoles, the concept is implemented by configuring a send as post or pre. It is important to understand a specific device’s routing path to know exactly which stage the send taps into, since the practical behavior can vary slightly between systems. Overall, postfader ensures that a channel’s effect or bus level follows the channel’s fader movement, supporting cohesive and responsive mix control.