I'm about to build a new system using Creative Lab's XFI Fatal1ty sound card and Logitech's Z5500 THX certified speakers.
Now, the speakers are high-end and boast Dolby Digital 5.1 THX decoding and have 3 x 3.5mm analogue inputs for front/rear/centre&sub. They also accept digital optical and digital coax inputs.... I assume the Dolby Digital and THX is to with decoding a purely digital signal from a PS2/XBOX/PC.
However, the XFI soundcard's manual states that "digital output is only concerend with 2.1 channel"! According to their manual "all PC soundcards (and other consumer DVD players) are obliged to limit their DVD Audio to 2.1"!
Is this correct?
Do I have to use the XFI's on-board decoder, and not pass the DVD sound to my Z5500?
Are they talking about DVD movies or the new future DVD Audio standard?
Please can someone answer these question!
Thanks in advance.
Sony and Philips, when they were setting up the DVD audio standard, limited DVD-A (DVD Audio, not DVD movie audio) discs to analog only as a copyright protection scheme. This will not affect DVD movie performance, but you cannot use a digital cable, only analogs, for DVD-A playback. This is probably one of the reasons which limited widespread DVD-A use, since it limits your sound quality to multiple DAC-ADC-DAC conversions rather than a single smooth digital transfer.
By the way DVD-A is not the new future DVD audio standard...its been around for ten years. It's going to be replaced by either Blu Ray or HD-DVD at some point (or an entirely new standard that's neither).
Some newer DVD (very expensive) players are cable of digital DVD-A by ripping the optical data to wav files in real time. But that's doesn't change anything for you unfortunately.
I would stick to X-Fi analog all the way anyway. You paid for the superior DACs (superior to your Z-5500 DACs). Might as well use them right? Going digital means you'd by forgoing their use, and probably would have been better off with a cheaper sound card.