General Settings

The General Settings dialog

Buffer Size

This setting is very important. Buffer size determines the latency of the audio coming out of LMMS (lower is better), but values too low for your computer may cause unwanted audio artifacts that render the program unusable. Faster computers will be able to handle smaller buffer sizes. If you experience pops, crackles, or stuttering audio, an insufficient buffer size is likely the culprit (see


  • Enable tooltips: This option enables informational tooltips to appear when hovering over controls. Keep this on.

  • Show restart warning after changing settings: This option enables or disables the warning pop-up window that appears after changing settings.

  • Display volume as dBFS: Typically, LMMS displays volume on a 0-100 range without units. This option changes volume displays to use dBFS, a standard unit across many digital audio workstations.

  • Compress project files per default: This option saves storage space by using the compressed .mmpz save file format rather than the larger .mmp format. Keep this on.

  • One instrument track window mode: This option allows only one open instrument window at a time. LMMS will automatically close the open instrument window when you open another one if this is enabled.

  • HQ-mode for output audio-device: This option improves the quality of playback sound for some output devices.

  • Compact track buttons: This option makes tracks in the Song Editor appear smaller by hiding the name of and rearranging the solo & mute controls for each track.

  • Sync VST plugins to host playback: This option enables VST plugins to utilize the song tempo for certain effects that would synchronize to song rhythm.

  • Enable note labels in piano roll: This option labels notes with their note name in the piano roll when enabled.

  • Enable waveform display by default: This option allows the master output oscilloscope to be enabled rather than disabled by default.

  • Keep effects running even without input: This option prevents effects from sleeping when they don't have input. Keep this on unless you have severe performance issues.

  • Create backup file when saving a project: This option creates a backup save file whenever you save a project when enabled. This can help prevent data loss. Keep this on.

  • Reopen last project file on start: This option opens the last project you worked on when opening LMMS rather than a blank project when enabled.

Plugin Embedding

  • No embedding:

  • Embed using Qt API:

  • Embed using Win32 API*:

* This setting is only available on Windows operating systems.


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The Directories dialog

Working Directory

This is where the user's own samples, projects, presets, etc. are stored.

GIG Directory

SF2 Directory

This is where the user's own .sf2 files are stored. This is typically somewhere in the working directory.

VST Plugin Directory

This is where the user's VST 2.4 plugins are stored. These can be either 32 or 64 bit plugins.

LADSPA Plugin Directories

STK RawWave Directory

Default Soundfont File

This is the location of a .sf2 file. If one is specified, the SF2 Player (see 5.13) will automatically load this file when an instance is created.

Themes Directory

Despite the name, this is actually points to where the current theme is stored. To change themes, set this path to the location of the desired theme itself.

Background Artwork

This is an image used for the background of the main LMMS window. Leave it blank to use the image provided by the current theme.

Performance Settings

The Performance Settings dialog


  • Auto-save interval: This slider determines the time between auto-saves.

  • Enable auto-save: This setting allows LMMS to periodically save a backup of your currently open project to help protect against data loss in the event of power outage, user error, etc.

  • Allow auto-save while playing: This setting allows auto-saving during audio playback.

UI Effects

  • Smooth scroll in Song Editor:

  • Show playback cursor in AudioFileProcessor:

Audio Settings

The Audio Settings dialog

Audio Interface

This option selects how LMMS outputs sound.

On macOS and Windows, SDL is the recommended interface.

  • Dummy (no sound output): This option disables audio output. Don't use this.

  • ALSA (Advanced Linux Sound Architecture)*:

  • JACK (JACK Audio Connection Kit):

    • Client-name:

    • Channels:

  • OSS (the Open Sound System)*:

  • PortAudio: PortAudio has two main configuration options, both of which vary between hardware configurations and operating systems:

    • Backend: This selects the audio driver, or "backend" used. Backends tend to be specific to an operating system, but some backends may be provided by additional audio hardware such as an audio interface.

    • Device: This selects the audio device, or hardware used. If your computer has multiple audio inputs and outputs, they will be visible in this list. If you use PortAudio and cannot hear any sound, you may have the wrong device selected.

  • SDL (Simple DirectMedia Layer): SDL only has one option, a text box where you can specify the device. If you leave this blank, a device will be selected automatically.

* This setting is only available on Linux operating systems.

† This setting is only available on Linux and macOS operating systems.

MIDI Settings

The MIDI settings dialog

MIDI Interface

This option selects how LMMS receives MIDI input.

  • Dummy (no MIDI support): This option disables MIDI support. Don't use this.

  • WinMM MIDI*:

  • Apple MIDI: Apple MIDI has no settings to change and is configured automatically.

  • Jack-MIDI: Jack-MIDI only has one option, a text box where you can specify the device. This is lmms by default.

* This setting is only available on Windows operating systems.

† This setting is only available on macOS operating systems.

‡ This setting is only available on Linux and macOS operating systems.