This quick walkthrough shows how to assign a MIDI controller knob or slider to a macro dial inside an Ableton Live audio effect rack, so you can tweak effect parameters live from your hardware instead of a mouse. It uses a filter mapped to a macro as the example, but the same steps apply to any device parameter.
The process starts with Live's MIDI Map Mode, which highlights every parameter available for mapping in purple. Select the macro you want to control, move the corresponding control on your MIDI controller, and Live links the two automatically.
Once mapped, the browser panel on the left shows the CC value tied to that parameter, and you can adjust the range there too. That range control matters for performance and mixing alike, letting you fine-tune how much movement on your controller translates to change in the sound, so a full knob turn doesn't overshoot the useful part of the parameter.