Jack:
What version of Audacity are you using?
Can you post a screen shots of Audacity Edit/Preferences....."Devices" and "Recording" sections?
I'm using "Windows Wasapi" as host in Devices section and "overdub" in the recording section.
Devices/recording and Devices/playback both set to my monitor speakers. The only other choice is Realtek and that may work just as well.
I used 2.1.0. Its an old version I downloaded but never installed. Maybe I need to download the latest version and try it.
Here's the screenshot.
UPDATE: I downloaded and installed Audacity 3.0.2 (latest version). It works and records the same way as the older version with Stereo Mix.
Now, back to getting the user's working. I don't know if you have done this, and I know its a hassle, but have you tried a clean install? If you have a spare drive that you can use that would be the best way to clean install as that wouldn't mess up your system drive, in case things don't change (but if Stereo Mix records with the clean install then you know what is needed). Just install Windows and needed drivers including the Gigabyte Realtek driver and Audacity - nothing else.
Thank you Jack for the screenshot
I am talking from the perspective of a laptop user , the majority of laptops do not even show you have stereo mix , not even if you show disabled devices in sound properties .
But once you find the registry hack for your brand and model of card it starts appearing in your recording devices and activates .
Now desktop's stereo mix is 50/50 chance that the driver has stereo mix taken care of , however if not , registry hacks can be applied as well to enable it .
As for Audacity and other audio editing apps , they all take advantage of stereo mixing if present , however if not , such as the case of laptops there is still alternatives they manage to implement to take care of that such as the one i discussed earlier .
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This link demonstrates few things to try in case of stereo mix absence or failure and list few of the common registry hacks that helps integrating them if not present :
How to Enable Stereo Mix in Windows 10
Problem is they manage to inject those hacks in the inf files of the audio driver rather than adding them via .reg files .
I see this is marked as "solved" but nothing about what solved the problem.
I too had same problem. From reading this thread, I looked into few things and tried to solve my problem, and I have somewhat got it to work.
This is what I did.
From Win 10 Search field: Open 'Sound Mixer Options'
On Output I had 3 options, VA2459 Series(NVIDIA HD Audio), Speakers, and again VA2459.
I chose 3rd option
Lowered Master Volume to 50
Open Audacity
Under the pause, play, record buttons, there are 4 selectable thingees.
I selected Windows WASAPI on left.
For Mic I selected VA2459 Series (NVIDIA HD Audio (loopback) & 2(stereo) Recording Channel.
For Speakers on the right, I chose Speakers (2-HD Audio device).
Now it's all set.
Push record on Audacity. Audacity won't record til sound is detected.
Open up a website that plays an audio, or play a sound file from your computer.
And my Audacity recorded the audio playing thru my sound card.
You can stop and replay the sound in Audacity and the audio will come out thru your speakers, but other sounds from other applications will not, so go back to Sound Mixer Options (App volume and device preferences), and change back your output to speakers, and adjust back your master volume.
Now it's back to way it was.
So every time you want to record some sounds, you have to do these steps. Which isn't optimal, but it works.
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