SPDIF and bit accurate playback with Creative Sound Cards
The following demonstrates some SPDIF connection details between two different Creative sound cards on
two different computers. These sound cards support SPDIF output for stereo PCM (uncompressed) at up
to 24 bit / 96 kHz. (Although playback of stereo wav content at up to 24 bit / 192 kHz is supported to the ANALOG
outputs, the digital SPDIF output is downsampled from 192 kHz to 96 kHz).
A 24 bit / 96 kHz stereo test file of a 400 Hz single tone at full digital amplitude was created.
A Toslink fibre-optic connection was made between the
SPDIF jacks of a Creative Audigy 2ZS Notebook sound card and a Creative X-Fi Elite Pro sound card.
The 24/96 stereo wav file was played back using MediaSource 3.30.21 on the Audigy 2ZS Notebook card
and the audio was received and monitored using the Creative X-Fi Elite Pro card with the X-Fi Creative Volume Panel
in Audio Creation Mode.
To show the effect of SPDIF received signal on the settings of the playback card settings, two configurations are demonstrated.
The first settings shown below are for the Audigy 2ZS playback sound card. The only difference in settings
for the two tests is the Enable Bit Accurate Playback setting for the Audigy 2ZS card is set to enabled
for the first test and then disabled for the second test.
In both tests below, all the settings for the X_Fi Elite Pro card in the Audio Creation Mode console and the
associated Audio Console are held fixed.
The screen shot below shows the X-Fi Elite Pro settings and SPDIF-in monitor (recording) level when the Audigy 2ZS card is set to ENABLE Bit
Accurate Playback. In this mode, both the Master Volume and WAV mixer sliders of the Audigy 2ZS transmitting card are inactive and the transmitted SPDIF
signal represents the full "bit accurate" wav data of the 24/96 file. However, it was noticed that the Audigy 2ZS WAV mixer level MUST be set
at any level greater than the minimum for a SPDIF signal to be sent.
The screen shot below shows the X-Fi Elite Pro with IDENTICAL settings and SPDIF-in monitor (recording) when the Audigy 2ZS card is set to DISABLE Bit
Accurate Playback. In this case, both the Master Volume and WAV mixer sliders of the Audigy 2ZS transmitting card are available to control the
send level over SPDIF and the received level, for the WAV level shown (~ 50%) is correspondingly lower:
