Fix an FSX add-on aircraft with no sound by checking sound.cfg, aliases, folder nesting, missing WAV files and Steam Edition install paths.
If an FSX add-on aircraft has no sound, its sound folder is usually missing, nested incorrectly, incomplete, or pointing through sound.cfg to an aircraft that is not installed. Confirm other aircraft have audio, then inspect the add-on’s sound selection, sound.cfg, WAV files and any alias before reinstalling anything.
How do I tell whether FSX or the aircraft is at fault?
Load a default FSX aircraft: if it has normal audio, FSX’s sound system is working and the fault is inside the add-on. If every aircraft, ATC and interface sound is silent, check the master sound toggle, FSX volume settings and Windows playback device instead.
FSX can also retain the playback device that was active when it started, so restart the simulator after changing headphones, speakers or audio outputs. Our guide to repairing simulator-wide FSX sound loss covers that separate problem.
| Symptom | Most likely cause |
|---|---|
| Every aircraft is silent | FSX or Windows audio setting |
| Only one add-on is silent | Missing sound folder, broken configuration or alias |
| Only one variant is silent | Incorrect sound= value in that variant’s [fltsim.x] entry |
| Engines work but warnings or switches are silent | Missing gauge, module, dependency or aircraft electrical power |
Which sound folder should FSX use?
The active folder is selected by the sound= line in the aircraft’s aircraft.cfg, not simply by whichever folder happens to be named sound. Back up aircraft.cfg before changing it.
- Open the aircraft folder. It should be directly under
SimObjects\Airplanesin the FSX installation being used. The folder normally containsaircraft.cfgalongside its model, panel, texture and sound folders. - Find the selected variant. In its
[fltsim.x]section, an emptysound=entry uses the folder namedsound. A value such assound=RRselectssound.RR. - Check the chosen folder. It must contain a valid
sound.cfg, local WAV files or a working alias. A frequent mistake is ending up with an extra level such asAircraftName\sound\sound\sound.cfg. - Check for an incomplete archive. Some downloads separate the aircraft and sound pack, or include support files outside the main aircraft folder. Extract the complete package while preserving its directory structure.
- Reload the aircraft. Restart FSX after correcting folders or configuration files so the aircraft and audio configuration are read again.
Do not place a normal aircraft engine-sound set in FSX’s top-level Sound directory. Standard aircraft sounds belong inside that aircraft’s folder. If the rest of the package structure is uncertain, follow our correct FSX aircraft installation layout.
How do I fix a broken sound.cfg alias?
An alias works only when the aircraft and sound folder named by sound.cfg exist in the same active FSX installation. A typical alias configuration resembles [fltsim] alias=B737_800\sound, which tells FSX to use that aircraft’s sound folder rather than local WAV files.
- Confirm the named donor aircraft is installed under
SimObjects\Airplanes. - Check that the alias uses the donor aircraft’s actual folder name, not its display name in the aircraft menu.
- Restore a removed default aircraft if the add-on expects it.
- If the package came from FS2004, check whether it refers to a donor aircraft that FSX does not include.
Do not point every broken alias at the first sound folder you find. The result may run, but piston, turboprop and jet configurations have different engine stages and sound behaviour. For a replacement set, use the proper FSX custom engine-sound folder and configuration method.
What if sound.cfg exists but the aircraft is still silent?
A non-alias sound.cfg must reference WAV files that are actually present and readable. Enable file-name extensions in Windows and check that the configuration has not become sound.cfg.txt; also verify that the referenced WAV base names correspond to files in the folder.
If only certain sounds are absent, the pattern usually identifies the fault. Missing interior or exterior engine audio suggests incomplete WAV files or entries in sound.cfg. Missing call-outs, warning tones or switch clicks may come from custom gauges or modules instead, and some sounds require electrical power or an engine-running state.
Install any documented gauges, modules or shared files supplied with the aircraft, but do not add unrelated DLL files merely to make the sound work. Complex aircraft may also require their own documented start procedure rather than FSX’s normal automatic engine start.
Does FSX: Steam Edition use a different sound setup?
FSX: Steam Edition uses the same basic aircraft sound-folder and alias system, but installers often write to the wrong FSX installation. Steam libraries may be on another drive, while older installers may detect a boxed-edition path or an installation that no longer exists.
Locate the active folder containing FSX.exe, then verify that the add-on and its sound files are under that installation’s SimObjects\Airplanes directory. Add-ons using custom modules can have separate compatibility requirements, covered in our explanation of FSX add-on compatibility with Steam Edition.