First off, some more test results - the routing is as described, and I am now monitoring 16 FxBus'es at the same time using the Peak plugin in the DSP. I test both six channel-audio and stereo audio and see which FxBus it goes to (consult my earlier posts as to which device connects to which FxBus). 1. With SPDIF/AC3 as default both stereo and 6-channel go to FxBus 0/1 2. With Master Mixer, stereo goes to FxBus 2/3 and 6-channel to FxBus 2/3/4/5/6/7. 3. With Wave 2/3 as default, all audio goes to FxBus 2/3 (including all 6 channels of multichannel file) 4. With Wave 4/5 as default, same as over on FxBus 4/5 5. With Wave 6/7 as default, stereo sound goes to FxBus 6/7, multichannel sound does not show up on FxBus 0-15) [I have no idea why] Conclusion is that changing the "default" in Vista sound panel affects which Wave Device sound is routed to. For me this was important learning, because when I started using kX I set "default" to 6/7 and got great stereo sound, but when I (as this thread emerged) wanted to get 5.1 sound I could not get Vista to give me that. Only when I changed the "default" to Master Mixer did I get the 5.1 sound I wanted. If there are some other experiments I could do to help figure out what Vista is doing, let me know. I like playing around with things.