Creating an connection between parameters that are each automated by 2 parameters

Presently, I’m working on an engine sound mod for a diesel engine.

I have included the engine unloaded and loaded sounds, a turbo sound, and an engine brake sound with the mod being for American Truck sim.

I’ve worked to get a turbo sound working when the engine brake is active the same way I have the turbo work for the load parameter based on automations linked to the rpm and load parameters except in place of load I use brake (0-1 parameter for engine brake application.)

While this is fine and dandy, since I have two separate turbos, it means when I go from a full load to full engine brake, the main turbo is immediately cut out and the engine brake turbo is spooling up as it was at a lower value since the brake value was at zero.

I have the automation curves for RPM identical for each turbo but I’m just needing to know how I can have the turbo that is currently silenced be held at the same value as the one that is audible based on it’s current parameters.

For example, when the engine is at 1600 rpm and full throttle, the turbo connected to the load parameter is at 0.87 while the turbo connected to the brake parameter is only at 0.34. When the situation is flipped to a max engine brake, the turbo connected to the load parameter is at 0.37 while the turbo connected to the brake parameter is at 0.79


I think you are looking for Global Parameters found under FMOD Studio | Parameters. This will keep both the turbo values the same. If that is not what you are looking for could you give me another example?

Hope this helps!

Thanks for responding Connor!

My apologies for my rather delayed response but, the way the entire bank is setup is that there is a folder titled ‘engine’ that the following 3D events are placed in:


While my initial question was with regards to the turbo parameter i figured out how to get it to work with only one turbo audio track in play instead of trying to sync 2. Now my problem is with the engine brake.

The main parameters are rpm, load, play. brake, and the turbo parameter I created that is governed by 3 separate automations effecting its value.

Now, from an example provided by SCS, they have the engine brake audio track on the engine 3D timeline. I would like to place it on the exhaust #D timeline as that sound is heard from the exhaust stacks rather than the engine under the hood. I have my max distance, Panner, and overall volume set up differently between the two timelines so there is further need to move it to the exhaust timeline to create a more authentic sound profile.

In the SCS example, the only parameters that are on the exhaust 3D timeline are rpm, load, and play with these parameters being seperate to the ones on the engine timeline.

So I guess my next questions are;

Does placing a parameter in a folder for a timeline isolate it’s current value to only that timeline

Should I create a separate brake parameter and place it in the exhaust folder as just a local file (the rpm and load parameters seem to be linked on the game’s end as they maintain the same value in game but are not linked in fmod

Should I create the brake parameter for the exhaust folder and have an automation directly linking it to the brake parameter found on the engine 3D timeline

Or should I create a new brake parameter that is outside both folders and use that parameter directly on the exhaust 3D timeline?

Thanks for your assistance



Could you provide a link to the example you are referencing here?

There are two types of parameters: local and global. Local parameters are isolated to that event, while Global parameters will share their value with any event that uses it. Folders don’t have an influence on the reach of a parameter. You can read more about Parameters under FMOD Studio | Parameters.

Folders don’t affect parameter reach, could you elaborate on what you mean by they maintain the same value? Are you changing them via code? If so, how?

You can’t link to parameters together in FMOD, however, you can use a Global parameter which will maintain it’s value across Events.

Folders don’t affect parameter reach. Reading more on Parameters will explain this further.

Here is where an example file can be downloaded, specifically the one for version 1.43 Documentation/Engine/Sound/Downloads - SCS Modding Wiki

“Folders don’t affect parameter reach, could you elaborate on what you mean by they maintain the same value? Are you changing them via code? If so, how?”

The value in question is the turbo parameter which I have on the engine event found in the engine folder.

This value is seperate to the turbo value that has it’s own timeline as I have been unable to determine how that parameter’s value is affected by the game.

So, my turbo parameter is affected by 3 parameters which are RPM, load, and brake.

I figured out how to get the turbo to work while being tied to both the brake and load parameters but setting the root pitch of the turbo at full spool sound to .67 instead of 1.00 as that is the turbo parameter value when the engine is at the governed rpm and when the load is at a full 1.00.

Initially, I had been trying to tie the rpm and load parameters found in the engine event to the turbo event itself.

I was also trying to to tie the brake parameter found on the engine event to a brake parameter I would setup on the exhaust event, that way the engine brake sound can be tied to the exhaust sound spatializer and panner (attenutation, sound size, directional output, etc) instead of the engine sound spartilizer and panner.

Have you had a look at our Example project which is included with the FMOD Studio download? We have set up two events Car Engine and Ride-on Mower which each have two parameters that work in conjunction to modulate the sound.