Measured with the new pitch probe: 440 Hz into the minted mic render came
back as 220 Hz off its capture side. The driver forwards the render
stream RAW into its mono capture, so a stereo-declared render (the
driver-default we inherited) turns every stereo frame into two mono
samples — half speed, octave down, exactly the field report. The mic
render now gets a coherent MONO 48 kHz format set stamped alongside its
name (PCM16 device format + float mix/host formats), making the engine
downmix before the driver crossing. The mic pump keeps pushing stereo;
shared-mode autoconvert handles the rest.