Casting from youtube on a Surface pro to a projector and the sound doesnt turn off the laptop

[RebeccaCl]

Normally when you cast (you have to cast the whole screen as the cast tab doesnt work at all), the sound mutes on the laptop but then you can hear the sound on the projector.  In this case on the Surface Pro, the sounds mutes on the laptop and the projector when you cast and then when you unmute the sound, the sound is on both the projector and the laptop.  I have tried every single variation of sound settings that I can try but nothing works.  I logged a ticket with Microsoft but they are saying is a problem with the Chromecast and they can't do anything!

[kcruzgonzalez]

Hello @RebeccaCl,

Thank you for posting in the community. I understand you are running into an audio issue where casting your entire screen from a Surface Pro to a projector results in the sound being played simultaneously on both the Surface Pro and the projector, even after manually unmuting. I apologize that you are experiencing this, especially since you confirmed the issue is specific to the Surface Pro and you've already tried various sound setting combinations.

You are correct: when using screen mirroring (casting the entire desktop), the sound should be rerouted entirely to the Cast receiving device (the projector's audio input), and the laptop should mute or at least offer a simple way to mute its output.

Step 1: Test Casting from a Different Computer Application

Since you mentioned you are casting your entire desktop (screen mirroring), let's try casting content that is supposed to reroute audio cleanly, which might give us better control over the audio mixer.

• On your Surface Pro, open a different application that supports casting (e.g., Netflix, Spotify, or Hulu within the Chrome browser, but use the app's internal Cast button, not the "Cast entire screen" function).
• Start casting this content.
• Check the Audio: Does the sound successfully mute on the Surface Pro and play only on the projector?
  • If the audio works correctly: The issue is specifically related to how the Surface Pro handles audio routing when performing a full desktop screen mirror.
  • If the audio still plays on both: The issue is deeper within the Surface Pro's audio configuration or the Chrome browser itself.

Step 2: Test Casting from a Mobile Phone

This step completely bypasses the Surface Pro and its Windows operating system.

• Use a mobile phone or tablet (iOS or Android).
• Open an app like YouTube or YouTube Music.
• Tap the Cast icon and select the Chromecast device connected to your projector.
• Check the Audio: Does the audio play only on the projector, and is the phone's speaker silent?
  • If the audio works correctly: This confirms the Chromecast and projector setup is functioning properly, and the issue is definitively located on the Surface Pro computer.
  • If the audio plays on both: This would indicate a problem with the Chromecast device or the projector's audio input settings (less likely).

Please perform both tests and let me know the results for each one. This will guide our next steps toward a resolution.

Regards,

Kevin

[RebeccaCl]

Hi Kevin thanks for your reply, I've done some testing as follows:-

1. Youtube on a browser - cast tab - it says failed and so doesnt work

                                               - cast screen - sound issue as described above whereby sound does not get muted on                                                      surface pro

2. BBC iplayer on a browser - casting both screen and tab works completely fine in that sound is muted on Surface Pro

3. Installed Netflix app on Surface pro - cast tab DOES work and sound is muted on Surface Pro

                                                                         - cast screen - same issue as above

4.  Tested all of these on Dell laptop and all variations of casting either tab or screen from any of these sites works correctly in that sound is muted on laptop and casted to projector.

5.  I have downloaded Netflix app and Youtube app onto my iphone.  I was able to cast successfully using Netflix, no sound on iphone.  For some reason casting wouldn't work from youtube app, it just said connecting but then never actually connected.

Regards

Rebecca