Stereo recording disappeared

I have been using Audacity 2.3.2 to record from a stereo USB mixer. Yesterday (2/11/20) I installed an update to Windows 10 and now stereo recording is not possible. I suspect the problem is related to the Windows 10 update, as problems with sound functions have been reported. Has anyone else encountered this, and are there any workarounds to allow stereo recording?

Check that the USB device is set to record 2 channels (stereo) in the Windows Sound control panel (in the “Recording” tab).

Check. USB device set to 2 channel stereo.

Is it working now? I can’t see your computer, so I only know as much about what’s happening as you tell me.

Stereo is still disabled even though sound is set to 2 channel stereo. Windows reports “device working properly”. Called Microsoft support and they couldn’t resolve it, but the external hardware and Audacity are working properly. This problem emerged right after the Windows update and nothing else has changed, so…

Where are you seeing that?

The stereo signal from my stereo mixer is being recorded by Audacity as pure mono.

What makes you think that?

Past recordings have used a wide left/right pan to separate two distinct instruments in the recorded track, with an appropriate and significant difference in the waveforms for left and right channels in Audacity. Using exactly the same settings Audacity now records exactly the same wave form on both sides and no stereo separation in the output. There is no mistaking the difference.

What mixer are you using?

If it has pan pots are the channels panned left & right or to the center?

What are you recording? How many channels/inputs are you using?

Mixer: Mackey ProFX16 USB. Regarding pan pots, please see previous post - I typically use a wide pan (L/R) for some of the instruments, basically center pan for others (I’m very familiar with pan functions). Typically 5-6 channels/instruments/mics into mixer, mixed down to 2 channel stereo output, ported to computer over USB. I’ve used this approach successfully in the past (as recently as 2/9/20) to get stereo tracks with excellent channel separation where desired. Now, using the same setup the signal going into both channels of the stereo recording track in Audacity is mono.

Audacity and Windows are set to record 2-channel stereo. Mixer is creating a verified stereo output. Yes, I’m sure it’s a mono signal into Audacity. Audacity not getting a stereo input signal, as witnessed by the lack of separation indicated on the record meter in Audacity; channels panned completely to one side show up equally on both meters (L/R), and the recorded output is clearly mono.

So that we can see what’s happening in Audacity, please save an “Audio device info” file ( and attach the file to your reply (

I have another possibility. Since this all happened at the Windows Update, what’s the possibility you’re really recording the room with your laptop built-in microphone instead of the mixer? That will give you a mono signal no matter what your settings say.

My laptop microphone will record in either mono or stereo, but only give me one single “show” no matter what the settings are. If I record stereo, I will get two tracks with exactly the same show on both.

Windows security updates are famous for blocking external devices and connections.


Audio device info file attached:
deviceinfo_mdobbs.txt (7.74 KB)
Regarding the laptop mic topic: Default to the laptop mic happens occasionally (e.g., if Audacity is started before USB is connected), but I’m aware of that and always verify the input and output devices before moving on.

channels panned completely to one side show up equally on both meters (L/R), and the recorded output is clearly mono.

That’s almost a clue. If you take one instrument or sound channel and pan it all the way left to all the way right, the Audacity recording signal more or less doesn’t change right? If it’s a single Audacity track, the soundmeter just sits there and if it’s two Audacity tracks, both meters track each other and never go away? That’s a mixdown and something in the system has to be performing that task. That’s not an accident of routing. That’s a job.

My favorite “hidden in the background” gremlin is Skype. Do you use Skype or any of the other Chat applications? I personally have had Skype sneak around while I was making coffee and change audio connections and configs. If you really offended the sound deities, the change will get stuck there whether Skype is running or not.


There’s something peculiar there.
The recording device is set to “Microphone (2- USB Audio CODEC) Host name: MME”.
The playback device is set to “Device name: Speakers (2- USB Audio CODEC ) Host name: Windows WASAPI”.

That shouldn’t be possible.
What is “host” set to in the Device Toolbar (Device Toolbar - Audacity Manual)

Host is set to MME.
Playback device set to “2-USB Audio CODEC” sends the output back to the mixer which is monitored (in stereo) at one of the mixer channels. This allows me to playback through the studio monitor system. Works great.

I don’t use Skype and, as I said before, I verify settings in Audacity and Windows prior to any session.

Did you do a Deep Shutdown after your update? Shift + Shutdown? Not regular Shutdown and not Restart.

Playback device set to “2-USB Audio CODEC” sends the output back to the mixer which is monitored (in stereo) at one of the mixer channels.

There’s also one other oddity. I don’t see any stereo channels on that mixer. How are you monitoring the stereo work through one of the mixer channels?


If you plug your headphones into the desk and change the pan on an input channel, can you hear it panning hard right / left through the headphones?

Koz: There are 4 true stereo channels on the mixer (9/10, 11/12, 13/14, 15/16), the rest are mono input but all can be panned left or right in the stereo signal that is ported to all the stereo outputs including XLR balanced L/R, TRS bal/unbal L/R, USB. There is a stereo headphone output that is used to monitor. Never heard of a “Deep Shutdown” so no, I did not. What’s the difference?