Explaining how Buttons Influence Sound:
~ The buttons file contains two types of file. One is an FMD file, and the other type is an EMD file.
FMD files are the main aerodynamic FM file of a plane, it in itself does not generate sound, what it does do is POINT to EMD file.
EMD files contain the engine data of a plane. Usualy a family of planes will share the same EMD file, and in that file will be data for many engines. The EMD file tells the game which PRS file to load for that plane's engine sounds.More about PRS files later.
What can go wrong here:
1) The FMD file can point to an EMD file that DOES NOT EXIST. The result of this is that the plane will explode immediately when the mission has finished loading.
2)The FMD points to an EMD file that exists, but does not contain data for THAT PARTICULAR engine. Same as numer 1, plane will explode.
3)The FMD points to a valid EMD file and sub-engine model, but that EMD file points to a PRS file that does not exist. In this case, your plane will have no engine sound. All other sounds will still be there.
FAQ:
What sounds are governed by the buttons file?
1) The internal (inside the cockpit) ENGINE sound
2) The EXTERNAL engine sound
3) The Start-up and shut-down sound of an engine (If it has any...rockets and some jets dont have any)
Does the buttons file influence any other sounds in the game?
No
If my plane loses sound sometimes, like when it idles, or when it revs very high, is the cause of this in buttons?
No, you have the wrong type of data in your PRS file for that plane.
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PRS files:
PRS files are the files that tell the game which sound files (WAV FILES) to use for an engine, and how those sounds should be handled by that game.
There are two places where PRS files can be found. One is in your "FILES" folder (IF YOU HAVE ONE).
you will find those here:
...your Main Game Folder\Files\presets\sounds\...
Or in the Mods folder. those will will be found in this place:
...your Main Game Folder\MODS\WHATEVER_FILENAME_YOU_LIKE\presets\sounds\...
You may see that if you have prs files, you have ones for all kinds of sounds, like guns sounds, bullet wizzes, cockpit sounds ect. Those do not concern buttons. The only PRS files that govern the engine sounds of planes, have names that start with the word "motor"
For example:
motor.BMW_800_Series.prs
or a start up sound looks like:
motor.Rolls-Royce-Merlin.start.begin.prs
and it's associated stop file for engine shut down will look like this:
motor.Rolls-Royce-Merlin.start.end.prs
What are the advantages of having sounds in your mods folder instead of the files folder?
Files in the files folder tend to load a fraction quicker, but this is marginal. It is a good place to have a bunch of files you want out of the way.
However, in your mods folder, you can put every plane's soundfiles in a seperate folder if you want. Easy thus to update or troubleshoot.
When the game loads, it will always give anything contained in your MODS folder priority over anything in the FILES folder. Thus, if you have two identical prs files, one in FILES and one in MODS, the game will ONLY load the one in your mods folder.
Now for the important bit:
The Buttons file only tells the game which PRS file to use. It does not do anything more than that. The prs file reacts to what the motor is doing, revving up, or down, or damaged...whatever it does. But the point is, what goes on INSIDE the PRS file, has nothing to do with buttons.
So I can, for example, take a jet engine's PRS file, and name it "motor.Rolls-Royce-Merlin.prs" , and then my Spitfires will have rocket sounds...it wont work very WELL, but it WILL WORK.
So, what does this tell you?
It means that, if you are missing a sound, or you want to give some aircraft the engine sounds of others, you simply look up the relevant PRS name in the SAS sound Matrix Xcell sheet (included in SAS Buttons downloads). Find the prs file of the sounds you like, make a copy of it, and name the copy for whatever PRS file you want it to represent.
This is also the principle behind the universal soundpatches.
So, enjoy your sounds, our buttons, and if you run into problems, let us know so we can fix them!
Salutes!
The SAS Team.