Hi Ecleamus,
Thanks for your reply. I did make my Xtreme Sound 7.1 as Windows default. When I did, the sound then came out of the new default sound card. In fact, I was working with one of your Support engineers (Ken or Kent) But what really wanted to accomplish was to make Sound Player.vi play wave file on the second sound card by changing the Device ID to 1, which didn't seem to work. Do you have any suggestions? By the way, I noticed there was a message in the forum from Juan Carlos (NI) saying that there was a work-around using Snd Write Waveform VI. If you search by typing "multiple sound cards", you can see it.
Mike Wu
LACMTA