I have Sound Balster Z and SteelSeries Siberia 800 headphones. Both support Dolby Digital Live encoding. I have connected the Siberia's base station using optical cable to the Sound Blaster's S/PDIF output.
I have the option to turn on DDL in the Creative control panel. Sound Blaster Z Control Panel
I also have the option to turn on "Dolby" in the Siberia base station options.
Alternating between the two options produces (subjectively) different sounds. Turning both on at the same time introduces crackling in the background.
I was wondering if anyone could explain whats going on and what are the proper settings for DDL and headphones connected through S/PDIF?