The purpose of the Auxiliary (or Aux for short) sends and returns is to share real-time effects between several tracks. Output from the tracks is mixed first, then the effect is applied, and the resulting signal is fed into the Master mix. The advantage is that only one calculation has to be done to apply the effect to several tracks. As the Real-Time Effects need a lot of CPU cycles, this makes it possible to apply more effects than would otherwise be possible.

The settings will be the same for all the tracks that share an effect. This could be an advantage or a disadvantage, depending on the project. The proportions of the tracks that go into the Aux mix can be set with the control knobs in the Expansion window, so each track can have a different setting for the strength of the effect.

Bring up the Send controls by clicking on the small Up arrow on a Mixer track.

The four level control knobs allow you to send this track to any of four Aux channels. This route splits off before the main level control slider in the Mixer track module, so this can be set at a very low level if you want the sound to travel mostly or entirely through the effect. Alternatively, you might want just a slight touch of the effect, in which case the main level slider can be left at a high setting, with the send control at a low setting.

Bring up the Return controls by either opening them from the Windows menu or hitting F5 on the keyboard. Click on one of the buttons to select the effect for that channel. The LED acts as a switch to turn the effect on or off. Click the button again to bring up the controls for each effect.

Adjust the level control to decide how much of this channel contributes to the final mix for the song.