M9 Docs   Settings & Preferences

Global Preferences

Almost all preferences can be edited via the main menu -> "Edit Preferences".
The "Edit Preferences" dialog panel lists all preferences and shows a description of the preferences.
You can double-click a preferences to edit it, or click the "Edit" button.

You can also tweak many of the used GUI colors.
This can be done via the main menu -> GUI -> Colors.
Several of these color preferences can also be set to "Auto Color" which means that the default color will be used.

User Folder

All preferences and settings are stored in the user settings folder.
By default that's the "User/Settings" sub-folder in the application folder. (the app folder is where the binary is, eg. MuLab.exe on Windows or MuLab.app on MacOS)

You have the option to indicate a different user folder by creating a text file named "UserFolderPath.txt" in the default user folder ie. MuLab/User/Settings
This text file must contain the line UserFolderPath=SomePath where SomePath is the path to the folder you wish to use as user folder.
One special case: When that line says UserFolderPath=@SystemAppData then the default system path for app data will be used.

Note that whenever the user folder doesn't exist or is not writable then also this default system path for app data will be used!
Within this system app data folder a "MuTools" sub-folder will be created and extra sub-folders to distinguish the user settings for the different MuTools apps/plugins per main version.
A typical example of a MuTools system app data folder on Windows is: C:\ProgramData\MuTools\MuLab\M9\User\

Editing Setup Files

Besides all the preferences that can be edited via the GUI, there are also some settings that are more technical and normally don't need to be changed, and so normally you don't need to read the following info. These advanced settings are only editable via the files in the "Settings" sub-folder in the User Folder.

Directly editing these setup files is meant for experienced users only!
If you are not sure about what you're going to do, then don't edit these files and only edit preferences via the GUI.

How to:

  • If you want to change something in these files, then first quit the app, then make the change and then launch the app again. So don't make changes while the app is active.
  • Settings in .txt files are always written on a single line in the format "SettingName=SettingValue". Settings and preferences in .xml files follow the standard XML syntax.


AudioSetup.Txt file contains all settings regarding your audio device. It is only used by stand-alone apps like MuLab, not by plugins like MuLab Plugin. Everything can be edited via the user interface and it's not recommended to edit this file manually.


MidiSetup.Txt file contains all settings regarding your audio device. It is only used by stand-alone apps like MuLab, not by plugins like MuLab Plugin. Almost everything can be edited via the user interface, there only is one extra preference:


It defines the time offset in microsecs to finetune the timing of MIDI output. This can be handy in case there would be a sync problem anywhere in the MIDI chain.


  • Logging : 0=No, 1=Yes.
  • PreferredProjectWindowRectangle : X,Y,W,H. Defines the default project window size when opening a new project window. If this is not defined new project windows are opened full screen.


This file is automatically maintained by the app and contains info regarding your preferred files and folders.


This XML file contains all info regarding your VST / CLAP plugins. Almost everything can be edited via MuLab menu -> Plugin Manager. Directly editing this file is not recommended except for the special cases explained below. Anyway, whenever you would edit (or delete) this file, make sure it is not in use i.e. MuLab App is not launched / MuLab Plugin is not plugged in anywhere.

If you delete this file, then the Plugin Manager database is emptied.

To ignore a plugin: set <Valid> to 0.

To delete a plugin: delete the relevant <plug>...</plug> block.

If you want a VST2 plugin to always receive zeroed output buffers, then set this line in that plugin's xml block:

Normally this is not necessary, but some plugins do not 100% follow the VST2 guidelines and need zeroed output buffers.

About ReGrouping a VST2 plugin's IO pins

Normally, when a VST2 plugin has multiple inputs/outputs, it will properly tell the app how these ins/outs are organized, i.e. whether these are mono or stereo.

Unfortunately there are VST2 plugins that don't properly report this. Technically: They don't support the effGetInputProperties/effGetOutputProperties calls.

In such case the app will default to group the ins/outs as stereo.

If this default behaviour does not match for a certain VST2 plugin, then you can overwrite how its ins/outs should be grouped by adding these lines to the relevant plugin block:

where i1,i2,i3... and o1,o2,o3,... are numbers that indicate the number of VST2 pins per MuTools audio jack. Note that the sum must match the total number of ins/outs for that VST plugin.

For example, if a VST2 plug has 4 input pins, but they should be grouped as 2 stereo jacks, then add this line to that plugin item in User/Settings/VstPlugins.Xml:

Similar story for outputs.

Of course all this is only necessary for VST2 plugins that don't tell the host how its IO pins are to be grouped. Normally a good VST plugin will report that to the host, and so you don't have to take this extra action.


This is an optional text file where you can list the preferred MIDI controller names. The format is: 25=My Controller Name 25

Note that the first controller is controller 0. Controller 1 is the second one.

It's recommended to create / edit this file when MuLab / your MuLab Plugin host is not active. After restart the changes will take effect.

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