FMOD version

X-Plane 12 runs the FMOD 2.02 engine, but since FMOD provides backwards compatibility, older 1.08 banks will load with no change. Nevertheless, you will NOT be able to use the “live update” feature of FMOD Studio 1.08 with X-Plane 12, because the newer version of the audio engine cannot connect to older Studio versions.

If you’re starting a new project for X-Plane 12…

The “Starter Project” download page now delivers a full FMOD 2.02 version. As you did with X-Plane 11, you must download a fresh “Starter Project” for every new X-Plane 12 project you intend to create.

Download the FMOD Project Template (v2.02 – for XP12)

If you’re upgrading an X-Plane 11 project…

We recommend you open your old 1.08 Studio project using FMOD Studio 2.02 and saving it as a 2.02 project. This will automatically upgrade your sound bank. Then you’ll need to address the following issues for it to work properly on X-Plane 12.

Output speaker format

You should set your output format as “Surround 5.1 on Desktop” because the master bank that lives in X-Plane now outputs this format by default. Your bank’s output will be automatically downmixed/upmixed for users with a different speaker system. Be sure to properly set your buses to this format both on the input and output of each bus to avoid inadvertently downmixing your sounds. The starter project is already set up for Surround 5.1.

Parameter names

As of FMOD Studio 1.9, some characters are no longer allowed in parameter names. So when you use datarefs as parameter names (on events or snapshots), you should replace

  • “/” with “.”
  • “[*]” with “[#]”

Thus, “sim/flightmodel2/engines/engine_rotation_speed_rad_sec[*]” will need to be expressed as “sim.flightmodel2.engines.engine_rotation_speed_rad_sec[#]”. Note that dataref names on the .SND files do not need to be changed, you only need to make this change when they’re used as parameter names inside FMOD Studio.

If you migrated an old 1.08 project to 2.02, you can use this tool to help you bulk convert all the parameter names in your project to the new format so you don’t have to do it manually. Open your 1.08 bank using Studio 2.02, save it, exit Studio and then run the tool.

Live Update

To be able to use “Live Update” you need to use FMOD Studio 2.02. You must enable the “Live Update” connection only after X-Plane has fully loaded your aircraft, or the changes you make to the bank won’t be reflected in the simulator. If you reload your aircraft, be sure to turn off and on “Live Update” again so it picks your external changes.


  • FMOD 2.02 “global parameters” are supported but untested at this time.
  • The “Highpass”, “Highpass simple”, “Lowpass”, “Lowpass simple” and “Parametric EQ” are considered deprecated on FMOD 2.02. All those are now superseded by the new “Multiband EQ” which has better CPU performance and functionality. We recommend you upgrade those effects if you’re using them.

New polyphonic events

When triggering sound events, X-Plane reuses the event instances to save resources, so if you have an event whose start conditions are satisfied several times in succession, the same instance will be stopped and retriggered each time. This might be undesirable under certain circumstances, such as triggering “clicks” for rotary knobs.

X-Plane 12 introduces the “EVENT_POLYPHONIC” directive for events. This forces X-Plane to disable instance reusing for that event and makes it trigger a new, separate instance of the same. Be sure to limit the “max instances” that can be triggered on the event (suggested 2-5) and the “cooldown time” to maintain low CPU usage and to prevent FMOD from triggering too many sounds at the same time, which could mute other sounds playing at that moment.

Environmental sounds

X-Plane now includes ambient sounds that depend on where the camera is placed in the world and its surroundings, as well as new rain, wind, hail and thunder effects. Ground equipment now produces sound too. All these are routed through the “Exterior Processed / Environment” bus, so it should “just work” with your existing banks.

As with X-Plane 11, it’s the responsibility of the aircraft developer to signal process these sounds when the user is located on the interior of the airplane, according to its sound insulation characteristics, and to do so only on the airplane interior, leaving the bus completely unprocessed when the user is outside (i.e. no mixer snapshot active). Be sure to preserve the 5.1 input/output format on that bus too.

The new environmental sounds that replace the old .WAV files in “Resources/sound/weather” don’t include rain or hail hitting the airframe, because it’s impossible for us to determine what material your aircraft is made of. So the developer should add their own sounds for the exterior and interior rain/hail impact on the airframe. You can use the following datarefs to that effect:

  • sim/weather/precipitation_on_aircraft_ratio
  • sim/weather/view/hail_ratio
  • sim/weather/view/snow_ratio

New copilot NAV radio morse datarefs

In addition to the existing datarefs for triggering the morse code / marker sound events tied to the pilot radio, X-Plane 12 now provides datarefs for the copilot side too. They’re named exactly like their pilot counterparts, but suffixed with “_copilot”:

  • sim/cockpit2/radios/indicators/morse_id_tone_nav1_copilot
  • sim/cockpit2/radios/indicators/morse_id_tone_nav2_copilot
  • sim/cockpit2/radios/indicators/morse_id_tone_adf1_copilot
  • sim/cockpit2/radios/indicators/morse_id_tone_adf2_copilot
  • sim/cockpit2/radios/indicators/morse_id_tone_dme_copilot
  • sim/cockpit2/radios/indicators/morse_id_tone_dme1_copilot
  • sim/cockpit2/radios/indicators/morse_id_tone_dme2_copilot
  • sim/cockpit2/radios/indicators/morse_id_tone_nav3_copilot
  • sim/cockpit2/radios/indicators/morse_id_tone_nav4_copilot

And you can modulate their volume based on:

  • sim/cockpit2/radios/actuators/audio_volume_nav1_copilot
  • sim/cockpit2/radios/actuators/audio_volume_nav2_copilot
  • sim/cockpit2/radios/actuators/audio_volume_adf1_copilot
  • sim/cockpit2/radios/actuators/audio_volume_adf2_copilot
  • sim/cockpit2/radios/actuators/audio_volume_dme_copilot
  • sim/cockpit2/radios/actuators/audio_volume_dme1_copilot
  • sim/cockpit2/radios/actuators/audio_volume_dme2_copilot
  • sim/cockpit2/radios/actuators/audio_volume_mark_copilot
  • sim/cockpit2/radios/actuators/audio_volume_nav3_copilot
  • sim/cockpit2/radios/actuators/audio_volume_nav4_copilot

Remember that sound events related to morse and marker should be routed to the Radios bus. You can look into the Airbus A330 implementation for reference.

6 comments on “FMOD 2.0 Upgrade Notes

  1. Hi! Does this mean that parametric EQ, low pass, etc.. no longer work in XP12? Or they work — and not recommended to use it anymore?
    Thanks 🙂

    1. They still work and you can still use them, but since FMOD Studio marks them as “deprecated”, that means they could disappear in future versions, so you should try to replace them with their newer counterpart.

      1. Hello Daniela;
        I have some X-Plane models (that work fine in 11.55) that are being used as AI and hence they are using AI multiplayer specific datarefs for wing and gear movement.
        Does FMOD recognize these, as when we used the FMOD from the actual aircraft, and replaced the datarefs with these, there was no sound.
        sim/multiplayer/position/plane1_gear_deploy float[10] y ratio Plane 1 gear deployment for 6 gear. 0 = up, 1 = down
        sim/multiplayer/position/plane1_flap_ratio float y ratio Plane 1 flap lowering 0 = clean, 1 = max flaps

  2. Ambient sounds? Does this mean we can now add sounds to objs in v12? I have been wanting to do this for years. I have many animated objs that I would love to “bring to life” audibly.

  3. I was wondering if there were any Cold&Dark start up procedures documented? I am specifically looking for the A330’s C&D start up.

  4. Any tips on how to summon hail so I can test hail sounds? I tried setting the precipitation to high and then lowering the temperature but the rain just transitions to snow as I lower the temp. I did see the sim/weather/view/hail_ratio go above zero at one point, but just barely.

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