I have noticed with the preserved collection, some sounds in some locomotives are not working correctly, example the BR 146.2 br 185.2 and others, sometimes the sound is distorted on acceleration and deceleration, and often in cruise the sound is not fluid, it jumps and sometimes repeats, and when it does happen the Framerate often skips. I have tested this with koln Aachen and the preserved German routes and same result. So in my opinion there is definitely a sound mix problem that needs to be addressed.