24bit/192 kHz X-Fi Elite Pro Playback

The Xi-Fi Elite Pro sound card is capable of sampling inputs at up to 24 bit/96 kHz resolution. However, with 192 kHz D/A converters, playback is supported for digital data at up to 24 bit/192 kHz (although the actual digital data stream at 192 kHz is not available at the digital output for copyright protection reasons).
To demonstrate this, a simple DVD-Audio test disk was compiled with programatically synthesized pure sine waves with stereo 24bit/192 kHz sine data. The DVD-Audio disk was played using Creative's DVD-Audio Player. The line-out response for playback of an 80 kHz sine wave is shown below using a suitable oscilloscope, clearly showing a bandwidth consistent with about half the digital data sampled rate of 192 kHz (96 kHz). Both channels are shown. Identical results are obtained if the basic 24bit/192 kHz wav file used to create the DVD-Audio disk is played back using MediaSource 3.x Player. For comparison, a 10 kHz sine wave of identical digital amplitude played back using the same DVD-Audio player configuration is shown. The 80 kHz line-out response is down from the 10 kHz "mid band" line-out response by about 1.5 dB, i.e. 20log(2.6/3.08)