Hi, I have made an implementation based on the msvad pcmex example that downmixes from 1-8 audio channels to 2 channels. In pcmex.h MIN_CHANNELS is set to 1 and MAX_CHANNELS_PCM to 8. After installing the driver on Win7, I have set the loudspeaker setup to 7.1. Now when I playback some stereo, 5.1 or 7.1 audio material the driver always receives 8 audio channels in CMiniportWaveCyclicStreamMSVAD::Init (pWfx->nChannels=8), and the channel mask received in CMiniportWaveCyclic::ValidateFormat is always 0x63f (the standard 7.1 setup). The behaviour I need is stereo->2 channels, 5.1->6 channels, and 7.1->8 channels. Actually I need to know the original format (the channel mask) of the audio material inside the driver so I can perform a proper downmix. How do I acquire the needed information about the audio material? Best regards, Kim