HI, Please work through these : VIDEO AUDIO

• https://support.google.com/youtube/topic/3014746
• https://support.mozilla.org/en-US/kb/fix-common-audio-and-video-issues
• https://support.mozilla.org/en-US/kb/html5-audio-and-video-firefox
• https://support.mozilla.org/en-US/kb/fix-video-audio-problems-firefox-windows

If still have issues and no information was provided when you created the question please : Try Firefox Safe Mode to TEST and see if the problem goes away. Firefox Safe Mode is a troubleshooting mode that temporarily turns off hardware acceleration, resets some settings, and disables add-ons (extensions and themes).

If Firefox is open, you can restart in Firefox Safe Mode from the Help menu:

• Click the menu button , click Help and select Restart with Add-ons Disabled.

If Firefox is not running, you can start Firefox in Safe Mode as follows:

• On Windows: Hold the Shift key when you open the Firefox desktop or Start menu shortcut.
• On Mac: Hold the option key while starting Firefox.
• On Linux: Quit Firefox, go to your Terminal and run firefox -safe-mode
  (you may need to specify the Firefox installation path e.g. /usr/lib/firefox)

When the Firefox Safe Mode window appears, select "Start in Safe Mode".

If the issue is not present in Firefox Safe Mode, your problem is probably caused by an extension, theme, or hardware acceleration. Please follow the steps in the Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems article to find the cause.

To exit Firefox Safe Mode, just close Firefox and wait a few seconds before opening Firefox for normal use again.

When you figure out what's causing your issues, please let us know. It might help others with the same problem.

Try to set this pref to true on the about:config page.

• media.forcestereo.enabled = true

You can open the about:config page via the location/address bar. You can accept the warning and click "I accept the risk!" to continue.

• https://support.mozilla.org/en-US/kb/about-config-editor-firefox

Pkshadow said

HI, Please work through these : VIDEO AUDIO

• https://support.google.com/youtube/topic/3014746
• https://support.mozilla.org/en-US/kb/fix-common-audio-and-video-issues
• https://support.mozilla.org/en-US/kb/html5-audio-and-video-firefox
• https://support.mozilla.org/en-US/kb/fix-video-audio-problems-firefox-windows

If still have issues and no information was provided when you created the question please : Try Firefox Safe Mode to TEST and see if the problem goes away. Firefox Safe Mode is a troubleshooting mode that temporarily turns off hardware acceleration, resets some settings, and disables add-ons (extensions and themes). If Firefox is open, you can restart in Firefox Safe Mode from the Help menu:

• Click the menu button , click Help and select Restart with Add-ons Disabled.

If Firefox is not running, you can start Firefox in Safe Mode as follows:

• On Windows: Hold the Shift key when you open the Firefox desktop or Start menu shortcut.
• On Mac: Hold the option key while starting Firefox.
• On Linux: Quit Firefox, go to your Terminal and run firefox -safe-mode
  (you may need to specify the Firefox installation path e.g. /usr/lib/firefox)

When the Firefox Safe Mode window appears, select "Start in Safe Mode".

If the issue is not present in Firefox Safe Mode, your problem is probably caused by an extension, theme, or hardware acceleration. Please follow the steps in the Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems article to find the cause. To exit Firefox Safe Mode, just close Firefox and wait a few seconds before opening Firefox for normal use again. When you figure out what's causing your issues, please let us know. It might help others with the same problem.

Terrific. I'll start cranking through that tomorrow. It's such an odd duck nobody could figure out troubleshooting techniques. I know we're all going to laugh when I sort why only some MP3's do it. Koz

cor-el said

Try to set this pref to true on the about:config page.

• media.forcestereo.enabled = true

You can open the about:config page via the location/address bar. You can accept the warning and click "I accept the risk!" to continue.

• http://kb.mozillazine.org/about:config

Thank you for your response. I didn't post a goal [slapping wrist]. Goal number 2 is to get everything working. I will check that setting. Goal number 1 is to see why that's happening. The answer to that is going to spill over on to the other forums. Why only some MP3's and only on one machine?

As we go.

Thanks again.

Koz

There is currently a problem with the mozillaZine website.

• https://support.mozilla.org/en-US/kb/about-config-editor-firefox

There has been a bug reported that affects some when playing some media files.

• bug 1461131 - Mono sounds play through left speaker only on multi-channel speakers

(please do not comment in bug reports
https://bugzilla.mozilla.org/page.cgi?id=etiquette.html)

I have a Left-Only problem and I'm using the plain stereo Headphone Out connection of a Mac Mini to drive a speaker power amplifier and separate speakers. No Sound Blaster.

Last two Firefox versions 61.0.1 and 61.0.0 both do it. So the version before that was OK? I don't use these sound files very often, so this is rough to nail down. I could just blow it all away and start over, but can I assume y'all want me to keep it going for testing?

Koz