> For the complete documentation index, see [llms.txt](https://docs.lmms.io/user-manual/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.lmms.io/user-manual/navigating-lmms/controller-rack.md).

# Controller Rack

Controllers are used to vary the position of a knob or other control over time using another signal such as an LFO waveform. They differ from automation because automation uses a shape drawn manually and usually the shape is not a repeated pattern. In contrast, LFO controllers use waveforms to yield a regular pattern.

![Controller rack](/files/-LuiMmxd0EeEcgji_9Ml)

The Controller Rack displays all the controllers created within this project.

There are 2 types of controllers:

* LFO controller
* Peak controller

The right-click context menu allows you only 1 options: "Remove this controller". You can change the names of the controllers by double-clicking on the current controller name.

## LFO Controller

LFO stands for **Low Frequency Oscillator**.

<img src="/files/-LuiMuj0XvUq_vTRE2MY" alt="" data-size="original">This button is the Controller Rack show/hide toggle button (F11). To add an LFO controller entry to the Controller Rack, click the Add button at the bottom of the window.

To edit the settings for a particular LFO controller entry, click the Controls button on the right side of the entry. The LFO controller settings are:

* 8 waveform option buttons
* 4 knobs
  * BASE: the center (or zero line) around which the wave oscillates
  * SPD: speed is the rate (frequency) of wave oscillation
  * AMP: amount is the size (amplitude) of the wave
  * PHS: phase offset is where in the waveform the wave starts its first oscillation
* 3 speed-multiplier option buttons

## Peak controller

A Peak controller allows you to use the volume peaks from an audio source to automate the values of a control. A Peak controller is similar to Gate, but with greater flexibility. Peak controllers commonly use the output signal of a percussion track to control the volume of a sustained sound on a different track. This results in the sustained sound being chopped up in time with the percussion. In LMMS, when you add a Peak Controller it is visible in the Controller Rack, but it's actually an **effect** applied to an FX-channel. If you click on the "Controls" button you'll get a window telling you to use the FX-channel's controls (magenta arrow). Therefore, to get to the Peak Controller settings, click the "Controls" button on the Peak controller entry in the Effects chain box (yellow arrow). Beware an FX-channel can have more than one Peak controller entry.