Sound Card Optical Out Why Won't My DVD Sound Play To All 5 Speakers When Plugged Into The Optical Port On My Computer's Sound Card?

Why won't my DVD sound play to all 5 speakers when plugged into the optical port on my computer's sound card? - sound card optical out

I have an external Sound Blaster sound card and a flagship DVD player with optical output, my DVD player to my sound card optical in port, the work seems related at least to some extent - no sound from computer speakers though.

The problem is that the only noise from my front left and front right - nothing from the center or rear speakers left and right at all.

The volume is complete - front, back, and the teacher. Audio settings on my computer, I also whole. Every sound, from my team staged with all the speakers very well, too.

Why not five tones through the speakers?