I agree with you for the Windows sound mapper (which is used by Windows
Recorder.
But if you have many audio devices, (onboard, HDMI, integrated in speakers,
etc), any decent audio application (Audacity is one) should allow you to
choose which device to use for recording and it doesn't have to be the same
than the one choosen in the Windows sound control panel; you might even be
able to use more than one device simultaneously.
I'd agree that what should be isn't always the case. I managed to get
into a major hassle/conflict. (Realtec drivers vs. AMD/ATI drivers.
The motherboard's a bit long in the tooth (DDR2 memory, for example).
Asus used a fairly obscure version of a Realtec sound chip, just to make
matters worse.
As a result, the mixer functionality does not work properly, with either
the AMD/ATI or the Realtec mixer setup not working properly.
The Windows version also might work, if the driver install process did
not muck with the registry entries quite so much. The bit about
OEM's rolling the driver modules into one package for install purposes
really made things much more difficult to deal with.
It is possible with a lot of hassle, to get the realtec drivers and
mixer to work, if the AMD drivers and mixer are disabled. This obviously
kills the HDMI output from the video card.
What I eventually decided to do involves using a much newer desktop
running Win 8 and a more conventional realtec sound chip. The newer
system also used speaker outputs for audio, not the HDMI video card outputs.
Audacity is also involved on both, and is used to modify special purpose
sound clips. Those are then used to simulate sounds from
Engines and other sound effects on electric motor powered models.
Sadly, this is actually a secondary issue. The primary one involves
cramming the sound card, it's speakers, and power source into RC Model
Aircraft. Space, CG, and weight are the main issues, followed by
locating the speakers such that the sound is projected properly.
If that isn't enough, any aircraft structural mods must preserve
strength, without significant additional weight.