Can anyone report having adjusted the volume of the PDC or the Gong, so that it is actually quiet in comparison typical human conversation?

FWIW the E70 X5 manuals I've read, indicate that the iDrive volume adjustment for the PDC and Gong is "in comparison to entertainment sound output". IOW it is NOT an absolute volume adjustment; it is a relative volume adjustment. And in my experience, even after setting it to the lowest volume available and having the "entertainment sound output" SILENT, it is still annoyingly LOUD

Talon Dancer