COMMAND_LINE_OPTIONS.md

FxSound Command Line Options

FxSound accepts a set of command line options that let you configure the app on launch, or push new settings to an already-running instance.

For example, run fxsound.exe --preset="Bass Booster" at any time to switch the running instance's preset without restarting it or affecting any other setting.

Each option's value must be attached directly to the option with = — e.g. --power=1. A space between the option and its value is not supported for these options; --power 1 is parsed as two separate, unrelated arguments and the value is silently ignored.

Options with numeric values that fall outside their valid range are silently reset to their default — no error is shown.

--balance and --master_gain are additionally rounded to the nearest whole number, and --filter_q and --volume_leveling to the nearest 0.5, matching the step size of their equivalent sliders in the Settings dialog.

Values containing spaces (preset names, device names) must be wrapped in double quotes immediately after the =, e.g. --preset="Bass Booster".

Option	Value	Description
--power=<0|1>	0 = off, 1 = on	Turns FxSound's audio processing (DFX) on or off.
--preset=<name>	Preset name (case-sensitive)	Selects the active preset. Only takes effect if power is currently on. Exclusive with the other preset commands below - see Preset commands.
--save_preset=<name>	New preset name	Saves the current (modified) settings as a new user preset and selects it. name is sanitized first - see Preset commands. No-op if power is off, the current preset isn't modified, or name is empty after sanitizing. Exclusive with the other preset commands below.
--overwrite_preset	(flag, no value)	Overwrites the currently selected user preset with its modified settings. No-op if power is off, the preset isn't modified, or the selected preset is a built-in preset. Exclusive with the other preset commands below.
--undo_preset	(flag, no value)	Reverts the currently selected preset's unsaved changes. No-op if power is off or the preset isn't modified. Exclusive with the other preset commands below.
--rename_preset=<name>	New preset name	Renames the currently selected user preset. name is sanitized first - see Preset commands. No-op if power is off, the preset has unsaved changes, the selected preset is a built-in preset, or name is empty after sanitizing. Exclusive with the other preset commands below.
--delete_preset	(flag, no value)	Deletes the currently selected user preset. No-op if power is off or the selected preset is a built-in preset. Exclusive with the other preset commands below.
--output=<device>	Output device's friendly name	Selects the audio output device. Must match a device name returned by Windows exactly.
--view=<1|2>	1 = Lite, 2 = Full	Switches the UI between Lite and Full view.
--language=<code>	Language code, e.g. en, fr, fi	Sets the display language. Falls back to the saved language, then the system display language, if omitted.
--num_bands=<n>	Integer, one of 5, 10, 15, 20, 31	Sets the number of equalizer bands. Default: 10.
--balance=<n>	Decimal, -20.0–+20.0	Sets the left/right stereo balance in dB. Default: 0.
--filter_q=<n>	Decimal, 1.0–3.0	Sets the EQ filter Q factor (controls the bandwidth of each band). Default: 1.0.
--master_gain=<n>	Decimal, -20.0–+20.0	Sets the master gain in dB. Default: 0.
--volume_leveling=<n>	Decimal, 0.0–4.0	Sets the volume leveling amount in dB. Default: 0.
--set_band_freq=<band:freq[,band:freq...]>	band = 0-based band index, freq = frequency in Hz	Sets one or more equalizer band center frequencies on a running instance. band must be less than the current number of bands; freq must fall within that band's allowed range or the pair is ignored. Running instance only.
--set_band_gain=<band:gain[,band:gain...]>	band = 0-based band index, gain = decimal, -12.0–+12.0	Sets one or more equalizer band boost/cut values in dB on a running instance. band must be less than the current number of bands, or the pair is ignored. Running instance only.
--set_effect=<name:value[,name:value...]>	name = one of fidelity/clarity, ambience, surround, dynamicboost/dynamic_boost, bass/bassboost/bass_boost; value = decimal, 0.0–10.0	Sets one or more effect levels on a running instance. Out-of-range values are ignored (left unchanged) rather than reset to a default. Running instance only.
--status	(flag, no value)	Writes the running instance's current state (power, presets, output devices, equalizer, effects) as JSON to %APPDATA%\FxSound\status.json; any other options passed alongside --status are ignored.
--run_minimized	(flag, no value)	Starts FxSound minimized to the system tray without showing the main window. On a running instance, only affects visibility for that launch (hides the main window instead of bringing it to the front).

Preset commands

--preset, --save_preset, --overwrite_preset, --undo_preset, --rename_preset, and --delete_preset are mutually exclusive: only one is processed per invocation, in that priority order, regardless of how many are passed together (any others are silently ignored). Each mirrors the equivalent item in the app's menu (Save New Preset / Overwrite Existing Preset / Undo Preset Changes / Rename Preset / Delete Preset) and the same enabled/disabled conditions apply, as described in the table above.

--save_preset also checks the user preset count against the max user preset limit before saving, and is a no-op once the limit is reached - matching the "Save New Preset" menu item, which disables itself at the same point.

Name sanitizing

Before --save_preset or --rename_preset acts on name, it's sanitized the same way the app's menu text entry sanitizes/validates preset names:

1. The filesystem-reserved characters < > : " / \ | ? * are stripped out.
2. The result is truncated to 64 characters if longer.
3. The final name is checked (case-insensitively) against existing preset names; if it matches one, the command is a no-op.

Each step runs in that order on the result of the previous one, so a name that only collides with an existing preset after character-stripping or truncation is still rejected - e.g. --save_preset="Mu:sic" is a no-op if a preset named "Music" already exists, since stripping the : produces a match.

Examples

Save the current modified settings as a new preset on a running instance:

fxsound.exe --save_preset="My Preset"

Overwrite the currently selected user preset with its unsaved changes:

fxsound.exe --overwrite_preset

Discard unsaved changes to the currently selected preset:

fxsound.exe --undo_preset

Rename the currently selected user preset:

fxsound.exe --rename_preset="New Name"

Delete the currently selected user preset:

fxsound.exe --delete_preset

Note: the preset name in --save_preset and --rename_preset is sanitized before use - see Name sanitizing.

Start FxSound minimized, with a specific preset and output device:

fxsound.exe --preset="Bass Booster" --output="Speakers (Realtek High Definition Audio)" --run_minimized

Switch a running instance to Pro view and turn power on:

fxsound.exe --view=2 --power=1

Tune the equalizer on a running instance:

fxsound.exe --num_bands=15 --filter_q=2.0 --master_gain=3.0 --volume_leveling=2.0

Set individual equalizer band frequencies and gains on a running instance:

fxsound.exe --set_band_freq="0:60,1:150" --set_band_gain="0:3.0,1:-2.5"

Set effect levels on a running instance:

fxsound.exe --set_effect="bass:7.5,ambience:4.0"

Change the display language:

fxsound.exe --language=fr

Print the running instance's current status as JSON:

fxsound.exe --status