Hi Herry,
 HB> What does XDR stand for and how does it work?
As far as I know, XDR stands for Extra Dynamic Range..not sure about the
way that it works, but apparently it utilises the Dolby HX Pro System which
reduces the amount of the bias signal in relation to the music signal. My
understanding is the higher the level of the music, the Dolby HX Pro bias
signal winds down to squeeze more music signal onto the tape, as on tape
it's a combination of both the bias signal and the music signal. The 
tapes are dubbed in real time, although if they are using high speed you
couldn't tell as the clarity from these cassettes are great. 
Cheers,
Frank
... "Yield to temptation, it may not pass your way again." - L. Long
--- FMail/386 1.0g
---------------