Just recieved the Logitech z5500 speakers for christmas. Currently on my pc I have a sound blaster Extigy and use a Monster Cable optical cable for output to the speakers. I pass everything straight through to the speaker's decoder since it decodes more than the extigy. Now, my question lies with my xbox, which I have connected through my optical in on my extigy. Whenever I play a game on my xbox, it comes through only as Dolby PLII and nothing more. All the digital and DTS options are enabled on the xbox and, when plugged directly into the speakers decoder, does come out in digital sound, but not when plugged in the extigy. I have tried almost everything and nothing works. Oh, and btw, when I play DVD's in my computer, I get DTS and Digital sound through my speaker decoder. Oh, and also, the Dolby Digital light on the Extigy is lit up when my xbox games are sending digital outputs. I feel that maybe the extigy is down-mixing my xboxes signal, but that doesn't make sense. Any help is appreciated. Thanks.