When ambient_fmod "Play everywhere" flag is on, the entity will play everywhere, but still have a sound origin. This origin being the entity's origin. It will sound like the audio comes from the ambient_fmod 's origin
With ambient_generic the sound "originates" from everywhere.
When ambient_fmod "Play everywhere" flag is on, the entity will play everywhere, but still have a sound origin. This origin being the entity's origin. It will sound like the audio comes from the ambient_fmod 's origin With ambient_generic the sound "originates" from everywhere.