Auzen Prelude 7.1 + Optical -> Logitech Z-5500 optical in = no rear channels?!

[ranker]

Well, I've run into a problem with one of my PC's. My 2 non-main gaming rigs are are running on the same desk. It's for use for dual boxing MMO games. Both machines have Auzentech Preludes and they're connected to my Logitech Z5500 speaker system.

The one machine that is connected via the analog cables does 5.1 sound just fine. The other machine that is connected via a digital optical cable from the Prelude's optical out to the Z5500's optical in, has a peculiar problem. The rear speakers do not work. I'm not sure why or how that is the reason. On the Logitch LCD speak display it says "Input: Optical || Effect: DTS Digital". I have correctly verified that the the windows vista speaker config is set to 5.1. When I run the individual speaker check, it demonstrates the same thing: no sound from rear speakers. When I click on a rear speaker, it plays it from the front corresponding speaker instead.

If anyone knows a workaround to get full 5.1 on my 2nd machine with the optical cable, please help an XS brother out.

Thanks in advance!

[16floz470ml]

There are two different kinds of dts if you double click your prelude audio icon and go into encoder. You have to enable both of them to get sound out of your rear speakers. This does not seem right to me but it was the only way I could get it to work.

When you use dolby digital you have to turn on xms 3d to get sound out of the rear speakers. That does not seem right either.

[ROBSCIX]

How do you have the control panel and Prelude set up?
If your using Vista and the Digital encoder on the Prelude, You set the Vista Audio control panel to speakers and cofigure it for 5.1. Set the Prelude for digital encoding...
Is this how you have the system set up? Atleast that should be right IIRC.