> 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/jp_2/3-navigating-lmms/3.13.md). # 3.13 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](https://2299305010-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LRtsae7H2l0Wn3A4biK%2F-LuiMc_cDOc4FMgNEYWm%2F-LuiMmxd0EeEcgji_9Ml%2Fimage.png?alt=media\&token=6c463664-9423-4e61-af19-83d398d52335) 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. ## 3.13.1 LFO Controller LFO stands for **Low Frequency Oscillator**. 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 ## 3.13.2 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.