noise from stereo mix

Windows 7; Audacity 2.0.5; .exe installer
I am trying to record audio from my computer. I am getting sound just as I hear it when I record, however I noticed when I turn on the level monitors they are picking up audio even when no sound is playing. To test I made a 1 minute recording and for the first 30 seconds I left it as is and for the last 30 seconds I muted the stereo mix. Initially I couldn’t really hear anything but I amplified the recording and I was able to hear noise for the first 30 seconds and complete silence for the last 30 seconds. Is there something I can do to stop this noise from being produced?

Recording what’s playing on the computer – assuming you’re doing it right – is not a standard process. That will never appear on the list of features when you buy a computer.

Some computers do this by bringing the sound all the way out to the analog parts of the sound card and then turn it around and bring it back. You can usually tell those because the Speaker Volume Control affects your recording. Those machines will always add soundcard noise to the show.


You can sometimes get around that by adding software. I think Total Recorder can do that with almost all versions of Windows.


alright, so I guess it seems like a hardware limitation. considering I’m using the built in sound card on a consumer laptop that is understandable. I’ll try out your suggested workaround and see if I get any different results.

The latest version of Audacity (2.0.5) has a new host added WASPI for loopback recording which should enable you to do this - see this page in the manual:

Works well on my W7 laptop - I don’t get control of the signal level, that has to be controlled in the application supplying the signal (webstream or whatever).


And see this tutorial from the manual:

which is part of this tutorial set:


Yes, it works great for me too. The sound is even better than the one returned by the sound card’s stereomix in that silence is really silence. Furthermore, it can record at 24 bit (normal is 16 bit).
The annoying is only that playback works only proper with a 0 ms audio buffer - a bad thing for other source/host recordings.