Recent versions of Windows 10 have made changes to some audio input processing.
Above is a screenshot of a Microphone Properties window, and attention is drawn to the section highlighted in pink which may appear in some devices.
The Signal Enhancements would appear to introduce certain non-linear behaviour.
I preface this with saying the ‘enhancements’ are probably hardware dependent (ie the chipset used and driver capability) but may also include Windows core, and this report applies to my specific configuration but hints issues that may be systemic.
That said, I performed a simple test switching an audio sine generator between two close frequencies and observed the level vs time in SpectrumLab.
The lower part of the screen is with ‘enhancement’ ON, the only change in the upper part is with ‘enhancement’ OFF. Continue reading Windows 10 – sound device Signal Enhancements