The interior sounds are too quiet.except if while in the seat you turn and face the either door the sound is at it should be.
Yes in all locos the ambient sound are to quiet, even if you turn the sound up to 400% in the UserSettings.ini its to quiet. You cant hear the engine in the Class 166.
Mine was increased to 100 and still couldn't here the engine, it's not my device as all youtube videos are similar.