I.e. if you start Chrome and play something like:

http://storage.googleapis.com/dalecurtis/buck720.webm

You won't hear sound for a few seconds. While in Edge the sound will start instantly. More interestingly, if you keep Edge running in the background and then retest in Chrome, Chrome will also play the sound instantly.

Looking at my receiver the reason seems to be that Edge keeps the audio rendering to your selected spatial setting (Dolby Atmos in my case), while Chrome alone ends up rendering 8-channel PCM. This triggers a mode switch on the receiver which is partially (possibly even largely) responsible for the audio gap.

It'd be nice to figure out what settings we need to apply to the audio endpoint to achieve audio playback without any gaps; since the delay is long enough that short sounds are completely missed.

Possibly we need to create a ISpatialAudioClient instead of an IAudioClient?

https://github.com/Microsoft/Xbox-ATG-Samples/tree/master/Samples/Audio
https://msdn.microsoft.com/en-us/library/windows/desktop/mt807491(v=vs.85).aspx