Since I don't have this problem I never really understood what people were talking about here until the second last time I visited the system of the friend, who has now caught my disease . The sound of RB was fine until the level dropped to a certain point, and the sound seemed to disappear! I thought, what the hell's going on here, the recording almost sounds like it was a completely different mastering!Clearly the above virtues definitely diminish when we go down towards lower formats. You get more darker passages between the musicians where the definition of space and air in between them starts to go missing. Hence you get this 'sudden leap of sound' from a musician playing on red book which could be misconstrued as dynamics.
Obviously this highlights a fairly typical problem that a lot of listeners seem to have with RB playback: through a combination of engineering and system configuration there is an end result of losing a lot of low level information on playback. And this was the first time I had noticed it so clearly on someone else's system ...
Frank