I-Firefox Community Forum

Hello. On/about 25jun2025 the sound on my Firefox videos stopped working from any source. I know enough to determine the problem is on Firefox. Videos on MS Edge worked fine. Sound works form VLC songs, etc. Sound does work with earplugs. Wondering if that could have caused the loss of speaker sounds. You think I could delete my current firefox and reinstall it. That would be a pain (an hour or so to set it up again.) Thanks, Bill

[Audio Issue] Firefox Causes Background App Volume Drop on Tab Focus — All Volumes at 100%, Issue Not Present in Portable

Issue Summary: Whenever I focus a Firefox tab (even a blank or safe mode one), the audio volume of background applications (e.g., Spotify) drops or changes audibly. It’s not a ducking effect (as all ducking settings are disabled), and Windows volume mixer shows all apps still at 100%. The issue happens only while Firefox is focused — not minimized, not unfocused.

Reproduction Steps:

Play music using Spotify or another app.

Focus any Firefox window or tab.

Background audio becomes quieter or altered — then returns to normal once Firefox is unfocused. Specifically on focus it will change system volume to 58, then return to what it was previously when unfocused.

System Info:

OS: Windows 11 (fully updated)

Firefox Version: 128.0.2 (issue present since at least 127)

Audio Output: Realtek and NVIDIA High Definition Audio (same issue on both)

Spotify Version: Latest Windows Store version

Windows Sound Settings:

Communications tab: "Do nothing"

All app volumes: 100%

No enhancements or spatial effects enabled

Troubleshooting Already Tried (No Success):

Step Result ✅ Disabled audio ducking in Windows No effect ✅ Disabled audio enhancements No effect ✅ Ran Firefox in Troubleshoot Mode (Safe Mode) Issue persists ✅ Changed Firefox audio backend to winmm via about:config No improvement ✅ Fully reset Firefox profile (about:support → Refresh) Issue persists ✅ Verified with Process Explorer (audiodg.exe shows activity on tab focus) Confirms session change ✅ Ensured all apps in volume mixer show 100% No volume mismatch ✅ Rebooted and tested cleanly Still occurs ✅ Tested Firefox Portable (fresh instance) Issue does NOT occur (portable version behaves as expected)

Additional Notes:

The issue appears to be triggered by the main installed version of Firefox only.

A completely clean portable version does not cause the volume change, suggesting something related to the system-wide install, global config, or registry entries is affecting it.

Even without extensions, without playing any video/audio in Firefox, just focusing the window causes this volume behavior.

What I Plan to Try Next:

Fully uninstall Firefox (including deleting AppData and registry leftovers), then reinstall cleanly to see if that resolves it.

Possibly test Firefox ESR if needed.

Request for Help:

Has anyone experienced Firefox causing audio session or DSP changes on focus, especially with audiodg.exe activity?

Could there be a hidden system-level or registry config that ties Firefox to a shared exclusive audio session?

Any way to trace which audio sessions Firefox creates and how Windows handles them?

Let me know if you'd like logs, about:support data, Process Explorer thread captures, or a video of the issue. I’d appreciate any help from the community in narrowing this down.

Thanks! —Justin

Hi,

I have been having this weird issue that I believe is being caused by firefox as no other internet browser has the same issue. When I'm playing music on spotify and I open firefox the sound goes quite bu the audio is still playing on spotify . One work around I have found is to take on of the tabs and use it to open a new window and the put it back with the others and the sound comes back again. I lost and need help as this is making it hard to want to use firefox which I have been a user of since it first came out.

Hello Team, I am having issues with Mozilla Firefox and Nightly Browser sound. If I use another browser, the sound is perfect. I have been using Firefox for years now and am accustomed to it, as well as Nighty, for all browsing needs.

Regards, Roopesh

I´m currently working on some courses in Udemy and all of a sudden the videos are not loading, is not my internet connection I deactivated all the extension to see if it was the case but nothing seems to be working

No matter what settings I change, I still can't get audio to play from Firefox. I can use other browsers and get audio so I know it’s not my computer. I’ve even tried to uninstall firefox and install the newest version with no luck on getting my audio issue resolved. If anyone has any advice for me, it’d be greatly appreciated

I take guitar lessons on line and the audio for the lessons has suddenly defaulted to muted and I can't unmute it even with repeated attempts. The speaker icon is x-d out. I've rebooted, gone out and back in to the site and tried it on another browser where it worked fine. Firefox is my preferred. What can I do?

Each time a video call comes in, the message on messenger, says Video calling is not supported on this browser. I've gone to the browser settings and cannot find anything that would change this. Help.

Bug in FireFox ... gives me a blank screen when trying to access this link : https://harrisonburg.org/music_scene/song_list/songs/Werwolves_studio.mp3

Has worked well for years, but with updates you broke it.

-(

I cannot play embedded Youtube videos, but they work when I open them in Youtube.

When embedded, after starting the video, I only see the circle animation (loading), but the video never starts.

Example: https://telex.hu/video/2025/07/30/gazdagret-plebania-katolikus-egyhaz-lidl-zoldterulet-lakossagi-forum

What I tried so far: 1. turning off hardware acceleration 2. private window 3. troubleshoot mode

The issue has been going on since a long time already, and present on both Windows and Linux Ubuntu.