Windows can have many sound devices. SRA by default, will use the sound device that is the Windows default. If you want SRA to use a different device, like your headphones, then you'll need to know the name of the device so you can change it.
How to find the names of your sound devices.
On the SRA menu, scroll down to the documentation section and you'll find a link to your server log. Withing the first 100 lines, you will find the sound devices listed, like in this example:
20180217210625.058: INFO : Sound Device = [Primary Sound Driver]: com.SIMRacingApps.Util.Sound.loadMixers(Sound.java:320)[main] 20180217210625.059: INFO : Sound Device = [Speakers (4- Logitech G430 Gaming Headset)]: com.SIMRacingApps.Util.Sound.loadMixers(Sound.java:320)[main] 20180217210625.060: INFO : Sound Device = [Headphones (Rift Audio)]: com.SIMRacingApps.Util.Sound.loadMixers(Sound.java:320)[main] 20180217210625.062: INFO : Sound Device = [2757-8 (NVIDIA High Definition Audio)]: com.SIMRacingApps.Util.Sound.loadMixers(Sound.java:320)[main]
The entire name of the device between the brackets, [ ], is what you want to use.
Changing all sounds to the same device
If you want to change all the SRA sounds to go to the same device, then use this setting. If there's a # in front of "sound-device", remove it. You can either map it to the name or the number. Note: Windows can change the number if another sound device is added, but not usually the name.
sound-device = Headphones (Rift Audio) or sound-device = 2
Changing the device for a particular sound.
Each sound can have it's own sound device. Same as above, just put the name of the sound first.
pit-count-down-device = Headphones (Rift Audio) or pit-count-down-device = 2
How to change the volume
Each SRA sound can have it's own volume. Also, there is a master volume to control them all at the same time. These two settings work together.
Volume values should be between 0.00 to 1.00, or between 2 to 100. It represents the percentage of max volume of the device.
sound-volume = 100 pit-count-down-volume = 90 pit-road-speed-volume = 60 shift-volume = 70
How to turn off a sound
Same as volume, sound can be turned on and off completely or by sound.
sound = N sounds-pitcountdown = N sounds-pitroadspeed = N sounds-shift = N
You can also set the volume to zero, to turn off a sound.