Sporting the
CMI 8768+
chip, which provides DDL support, it goes without
saying that this is the main reason you would want to
purchase this version of the Xtreme Sound 7.1 soundcard,
which allows audio output to be converted into a Dolby
Digital 5.1 stream in real-time.
Since the release of
NVIDIA’s nForce motherboard there’s been a lot of talk about
this feature and having it is no doubt perceived to be a
benefit, some of which include (1) Single cable connection
for all multi-channel Output, and (2) S/PDIF output offers
higher quality than Analog Output.
While Dolby Digital
is a ‘lossy’ encoding format, this has generally been offset
by the hardware decoder’s DAC being of better quality than
the soundcards is. S/PDIF output can also offer some quality
improvement as processing will occur outside of the PC
(which should mean less interference). Using only a single
cable minimizes setup time and issues as well. Bear in mind
that 7.1 output is only available using Analog output
though.
As with the NVIDIA
nForce motherboards I have used there seemed to be no
noticeable effect on performance regardless of whether DDL
was enabled or disabled. Similarly 3D positioning remained
unchanged.
Music and DVD
Playback
For testing music
playback I used
foobar2000
(Configured as detailed in our
foobar2000
guide), with only the Advanced Limiter DSP
in use. Resampler was unnecessary given that the
Xtreme Sound 7.1 could play 44.1kHz sources without
resampling. DTS Audio CDs should
also play just fine as a result. DVDs were tested using
WinDVD.
Testing was carried out
using a variety of FLAC (Free
Lossless
Audio
Codec),
LAME VBR and M4A VBR encoded tracks from albums such as E.S.
Posthumus - Unearthed, Dario Marianelli – V For Vendetta,
Rob Dougan – Furious Angels and various film scores from
Hans Zimmer, John Williams, Basil Poledouris and Danny
Elfman. DVD used included The Matrix Reloaded and
Revolutions, Family Guy: Stewie Griffin - The Untold Story,
Batman Begins, and some others.
Output quality was
pleasant enough, not quite as detailed or tight as you would
find with the more expensive soundcards but that is neither
surprisingly nor unreasonable, and in general something you
are less likely to notice depending on the quality of your
speakers. Certainly it’s fair to say that the audio quality
was better than most comparable offerings and integrated
solutions.
As indicated earlier, a
10-band equaliser is available should you wish to tweak
output further.
The Xtreme Sound 7.1
hardware is well suited to DVD Playback, plus 7.1 analog
output and Optical S/PDIF output ensure you will have no
problems connection wise; just switch the S/PDIF output mode
to PCM 2 CH and you should be all set for Dolby
Digital/DTS S/PDIF output.
