Some useful notes on fixing audio problems with SDR receivers

In Windows 10 the sound system can decide it knows what you want better than you do and makes assignments of device to application behind your back. This may need to be cleared for some SDR purposes. Here are some ideas.

Bote Man on groups.io:Create a shortcut on your Windows Desktop to
C:\Windows\System32\mmsys.cpl
which brings up the Windows Sound control panel. This bypasses the ridiculously huge and unhelpful management windows introduced in Win11 and later versions of Win10.

Check what your default audio output device is.
That is where all sound will go without further action.
Sound Mapper often does exactly what you want: it sends sound to the default audio device selected in Sound Control Panel. So when you unplug your headphones it reroutes audio to the speakers, for example.

Also check Windows Mixer
C:\Windows\System32\SndVol.exe
to ensure that your particular sound subsystem doesn’t have the desired output device muted or turned all the way down to zero.
It’s worth playing around with these settings to familiarize yourself with how the operate.

There are also 3 different Windows “Port Class” audio interfaces available under the hood. Don’t ask me why or what each does, I just learned this stuff from Eugene Muzychenko in the help file for Virtual Audio Cable:
WaveCyclic – “most simple and reliable”
WavePCI – “less latency than WaveCyclic”
WaveRT – “newest and most efficient”

He did a hell of a lot of research on Windows audio and it sounds like a wee bit short of a nightmare to sort out, so just figure out what works for you and go with it.
Just remember to check your settings after a Windows Update or other change to your applications. Don’t assume that it will work in the future just because it worked in the past.