Stereo Mix is a hidden recording device that captures whatever your PC is playing. People turn it on for two reasons: to record system sound (in Audacity, OBS or a call), or to copy sound to a second pair of headphones or speakers with “Listen to this device”. This guide covers enabling it on Windows 11 and 10, using it for two outputs, and what to do when it’s missing or misbehaving.

What Stereo Mix is (and why some PCs don’t have it)

Stereo Mix is sometimes called “What U Hear” or “Wave Out Mix”. It isn’t a Windows feature: it comes from your audio driver, most often Realtek’s. If your PC uses a different chip, a USB audio device, or Microsoft’s generic driver, Stereo Mix usually doesn’t exist, and no setting will make it appear. Checking takes two minutes.

How to enable Stereo Mix on Windows 11

  1. Open Settings → System → Sound.
  2. Scroll down and click More sound settings. The classic Sound window opens.
  3. Go to the Recording tab.
  4. Right-click an empty area and tick Show Disabled Devices and Show Disconnected Devices.
  5. Right-click Stereo Mix and choose Enable.

You can also reach the classic window by pressing Win + R, typing mmsys.cpl and pressing Enter.

How to enable Stereo Mix on Windows 10

  1. Right-click the speaker icon in the taskbar and choose Sounds (or Open Sound settings → Sound Control Panel).
  2. Open the Recording tab.
  3. Right-click → Show Disabled Devices.
  4. Right-click Stereo Mix → Enable.

Play sound on a second device with “Listen to this device”

  1. Make sure your first headphones or speakers are the default playback device.
  2. In the Recording tab, double-click Stereo Mix and open the Listen tab.
  3. Tick Listen to this device.
  4. Under Playback through this device, pick your second headphones or speakers.
  5. Click Apply.

To change the second device’s volume, use Stereo Mix’s Levels tab. The first device keeps its normal volume control.

Never pick your default device under “Playback through this device”. You’ll feed the sound back into itself, which sounds like an echo or a howl.

Stereo Mix is missing: what to try

  1. Show disabled and disconnected devices. It’s hidden more often than it’s absent.
  2. Check which driver you’re running. Open Device Manager → Sound, video and game controllers. “High Definition Audio Device” means Microsoft’s generic driver, which has no Stereo Mix.
  3. Install your PC maker’s audio driver. Download the Realtek driver from your laptop or motherboard maker’s support page (not a random driver site), install it and restart. This often brings Stereo Mix back.
  4. Check it isn’t disabled in Device Manager under Audio inputs and outputs.
  5. Accept that some PCs don’t have it. Many modern laptops, and anything using USB or Bluetooth audio as the main device, simply don’t offer it.

No Stereo Mix? The two alternatives that work on any PC are Voicemeeter (free, more setup) and a dedicated app (below).

Stereo Mix shows no sound (flat green bar)

  • Play something and watch the level meter next to Stereo Mix in the Recording tab. If it doesn’t move, Stereo Mix is listening to the wrong output. It only captures the Realtek device it belongs to, so the default output must be a Realtek output (speakers or the headphone jack), not USB or Bluetooth.
  • Check Stereo Mix isn’t muted in its Levels tab.
  • Untick Allow applications to take exclusive control in your playback device’s Properties → Advanced. Exclusive-mode audio skips the mix.

How to record your PC’s sound with Stereo Mix

The other big reason to enable Stereo Mix is recording what your PC plays: a stream, a game clip, or both sides of a call.

Audacity

  1. Enable Stereo Mix as above.
  2. In Audacity’s toolbar, set the Recording Device to Stereo Mix.
  3. Click Record, play the sound, then Stop and export.

No Stereo Mix? Audacity can record without it. Set the Audio Host to Windows WASAPI and choose your speakers or headphones marked (loopback) as the recording device. This works on almost every PC, including with USB and Bluetooth outputs.

OBS Studio

OBS doesn’t need Stereo Mix at all. Its Desktop Audio source captures whatever your PC plays. If you also enable Stereo Mix as a microphone source in OBS, you’ll record everything twice and hear an echo, so use one or the other.

Recording calls

Stereo Mix captures what you hear, not your microphone. To record both sides, add your microphone as a second track (Audacity, OBS) or use the call app’s own recording feature, and always tell the other person you’re recording.

The limits of Stereo Mix for two outputs

  • Two devices maximum: one default plus one “listen” target.
  • Built-in lag on the second device that you can’t adjust. With Bluetooth, the gap can be very noticeable.
  • Drift: over a long film the two devices can slowly fall apart.
  • Fragile: driver updates and device changes can quietly reset it.

If those get in the way, here’s the one-click option: