You can add engines by activating the appropriate menu item within the "add" submenu of the "edit" menu item. You may change the properties of an engine by opening the properties dialog from the context menu. From the context menu you may perform some other tasks, too.
To move up or down an engine open context menu and activate "up" respectively "down" entry.
To show or hide an engine open context menu and activate "show" respectively "hide" entry. Note the engines won't be hidden entirely they are just collapsed.
To rename an engine open context menu and activate "rename" entry.
To remove an engine open context menu and activate "destroy" entry.
To open properties dialog open context menu and activate "properties" entry. There you might link, resize or asign LADSPA effects to channels. NOTE for LADSPA sink or generators aren't supported, yet.
Within properties dialog you can link lines or add effects and adjust audio-channels/pads.
The output tab lets you mainly perform linking and adding effects.
The input tab does the same as output tab in view of input lines.
Do linking in batch mode.
Adjust audio channels or input/output pads.
The LADSPA browser gives you choice of available LADSPA plugin. It lets you modify the controls to be used.