Ecasound LADSPA Plugin Environment Variable

This article explains how the Ecasound digital audio workstation locates LADSPA (Linux Audio Developer's Simple Plugin API) plugins on your system. It identifies the specific environment variable required for this process, details how to view and modify its value, and outlines the default directory paths Ecasound searches when the variable is not explicitly defined.

The Environment Variable: LADSPA_PATH

Ecasound checks the LADSPA_PATH environment variable to locate LADSPA plugin binaries (.so files).

Like most Linux audio applications adhering to the LADSPA standard, Ecasound consults this variable at startup to build its list of available audio effects and processing modules. The variable consists of a colon-separated list of directories, similar to the standard system PATH variable.

Default Directory Fallbacks

If LADSPA_PATH is not set or is empty, Ecasound typically falls back to standard system locations. Common default directories include:

If your plugins reside outside these default paths and LADSPA_PATH is unset, Ecasound will not be able to locate or load them.

Viewing the Current Configuration

To check whether LADSPA_PATH is currently defined in your shell session, run:

echo $LADSPA_PATH

If the command returns a blank line, the variable has not been configured, and Ecasound will rely on its internal default paths.

Setting or Modifying LADSPA_PATH

To specify custom directories, you can export LADSPA_PATH in your terminal session or add it to your shell configuration file (such as ~/.bashrc or ~/.zshrc) for persistent access across sessions.

Setting a Single Directory

export LADSPA_PATH="/custom/path/to/ladspa"

Setting Multiple Directories

Separate each path with a colon (:):

export LADSPA_PATH="/usr/lib/ladspa:/usr/local/lib/ladspa:$HOME/.ladspa"

Verifying Plugins in Ecasound

Once LADSPA_PATH is properly set, you can verify that Ecasound successfully detects your installed plugins using the interactive mode or the command-line query options:

ecasound -el

This command prints a complete list of all LADSPA plugins found within the directories specified by LADSPA_PATH. If a plugin does not appear in the output, ensure its .so file has appropriate read permissions and is located within one of the declared paths.