How do I enable Stereo Mix when my headphones are plugged it?

I do not use USB headphones. My headphones are plugged into the stereo audio jack in my laptop. My laptop is a Dell, and it is running Windows 10.

Usually using Stereo Mix (which appears as an entry in the "recording" tab in the Windows audio control panel), I'm able to have sound recording software monitor and record the output to the speakers. This is useful when running software that produces sound, but has no feature to save the sound to a file. Stereo Mix allows me to run separate software to record the sound, as it plays from the first piece of software, so I can save the sound to a WAV file.

Unfortunately. This seems to only work when my headphones aren't plugged in. As soon as I plug in headphones, Stereo Mix stops recording the audio signal coming out of the speakers. How does Stereo Mix work? Does it work digitally to record the data being sent to the audio hardware? Or is it actually an analog-to-digital-converter that measures the analog voltage being sent to the speakers? Is Stereo Mix simply incapable of measuring the analog signal that goes to the headphones, because headphones use different wires to carry the signal than is used by the internal speaker (thus preventing Stereo Mix from being able to even see the signal)?

If it's not a problem with diffferent wires being used in the hardware for the headphones, then it must be a problem with how the sound drivers are programmed, as if it's not a hardware defect, then it should be able to record the digital data being sent to the audio hardware (regardless of whether the final destination of the signal is the headphones or the internal speakers).

I hope somebody can solve this, and recommend a way to enable Stereo Mix to be used, even when the headphones are plugged in.

Thank you, I had the same problem and the video was very helpful.

Let me write down my specific settings, for those who are not able to watch the video.

Code:

== Playback ==

Speakers
>> Default device
>> Level: 50%

Headphones
>> Default communication device
>> Level: 22%


== Recording ==

Microphone
>> Default device
>> Default communication device
>> Listen
>>>> Listen to this device > ON, through Speakers
>> Level: 84% +20dB

Stereo Mix
>> Listen
>>>> Listen to this device > ON, through Headphones
>> Level: 100%