How do I force single (only) channel audio in youtube/flash videos to play in both (left/right) channels?

Question

Occasionally, I find Youtube videos that have only one audio channel (only left or only right); example video (left channel only).

This is quite annoying, especially with headphones on, as I hear sound in one ear, and no sound in the other.

So, I want to be able to easily force dual mono (Left+Left or Right+Right) when I find that kind of video, and switch to normal stereo after I finish watching it.

• I have my headphones plugged well / I don't create audio/video - I want it for real-time playback only,
• In Windows audio config, setting balance 100% to Left / Right doesn't help (I have either still only left when moved to left, and no sound at all when moved to right), I've checked all the configurations in Control Panel > Sounds and Audio Devices > Audio > Sound Playback > Advanced like suggested in this post, in conjunction with moving balance left/right, and it doesn't seem to have any impact on actual sound I hear in headphones,
• No need to mix L with R, I just want L+L or R+R,
• I prefer software solutions to buying a stereo-to-mono adapter,
• Free solutions please, no $$$ ones, neither trials etc.,

• In Control Panel > Realtek HD Sound Effect Manager I can turn on various mumbo-jumbo effects like: Concert Hall / Hangar / Bathroom / whatever environment (and in fact it makes the sound appear in two ears, but well, it's ridiculous to do this;), but there is no Dual Mono option.

• Finally, I know I can force L+L or R+R in VLC Player which supports Youtube (well, a little hack is needed, because Youtube internals change from time to time) but it is not very convenient to launch VLC just to play Youtube video - I want to keep it in the browser, I use Firefox generally (but well, if I don't find easier way, I will launch it in VLC).

Answer 1

I just accidentally found a lame and hacky but working way to solve the issue - plug the headphones halfway, instead of fully, to the port :)

Answer 2

Windows 10:

Windows Settings > Ease of access > Audio, and on the right panel just toggle "Turn mono audio" to "ON".

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Original answer now obsolete in updated Windows 10: Windows Settings>Ease of access> Other options> Audio options: Turn mono audio "ON".

Answer 3

Free, no additional software required for most: Use any basic "vocal cancellation" or "Headphone Virtualization" feature. It is offered by many audio drivers, e.g. with the standard Realtek driver, presents in most Windows systems:

Right click on the loadspeaker symbol in taskbar, click "Playback devices". Right click on the active audio device, go to the tab "Enhancements". Check "Immediate Mode", uncheck "Disable all sound effects" (Already default). Check "Vocal cancellation" or "Headphone Virtualization".

(Works for all audio with sound only on the right or left channel. Reason: Simple voice cancellation works by duplicating and inverting the audio of one channel and adding it to the other channel, resulting in a cancellation of the central audio. If only one channel has sound, we just get the desired duplication.)

Answer 4

Right click on sound volume in taskbar, playback devices.

Right click on active audio device.

Properties -> Levels

Balance, set left / right till it sounds ok.

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Remember to reset after the one video, or you'll then be deaf in that ear.

Answer 5

To fix one ear problem:

1. Open Start menu
2. type mono
3. enable mono :]

edit: works in windows 10. (one solution. not the ultimate solution. if there is one)

Answer 6

Firefox implements advanced config (about:config in addressbar) called accessibility.monoaudio.enable

Answer 7

When having the same problem, I use 2 programs.

The first one is Soundflower. You can do some routing with that, but it's not as practically as one would like. The important thing is that it creates a virtual input and output interface. So you can direct the output of your system to this virtual inout and then reroute it back to your interface. In order to do that, I use LineIn. This programs has the feature of selecting the routing of each channel (left and right) for the input AND the output. You can simply route the active channel to both left(1) and right(2) channels.

I am not sure I explained it so well, so here it goes again:

• Install Soundflower & LineIn.
• Soundflower creates a virtual Interface (actually 2 but anyway), which you can choose as system output. But of course if you do it, without rerouting the Soundflower out, you won't hear a thing.
• You launch LineIn and you choose Soundflower as input and your physical interface as output. If you press "Pass Thru" then you hear the same thing (only one channel). That's solved easily: You click "Advanced" and under Input Device Settings, you choose Left Channel:1, if the video only has left or 2 otherwise. Then you choose the same for the Right channel. You click Ok and then Pass Thru.
• You got it! You have the same audio in both channels.

Answer 8

I was also looking for this exact same solution and could not find a complete answer anywhere, but through a combination of solutions I solved my issue. It's a bit hacky (like the accepted answer) but it worked well enough for me.

I used the VLC solution, right clicking on the video then choosing 'Audio --> Stereo Mode --> Left' so that it was only playing the audio from the LEFT channel (the only channel my video had audio on).

HOWEVER! Like the original poster I was attempting to play a YouTube/Flash video that had this problem. So my added solution was to implement one of the YouTube video Download hacks/extensions to allow the option of downloading the video to an .MP4 which I was then able to play with VLC.

Good YouTube Download Methods: Download YouTube Videos as MP4 https://addons.mozilla.org/en-US/firefox/addon/download-youtube/?src=search Video DownloadHelper http://www.downloadhelper.net SaveMedia/KickYouTube http://kickyoutube.com etc.

EDIT: Even though the OP and I were personally looking for software solutions, I see others attempted and incorrectly offered cable/adapter solutions (the picture below is a stereo to dual stero adapter). So I will add a correct adapter solution for those so inclined, as it's really not that expensive: You're going to want to split the stereo to each channel Left/Right using something like this: https://www.amazon.com/Hosa-YMM-261-Stereo-Breakout-Cable/dp/B000068O5H/ And depending on whether the internals of those two separate channel plugs are mono or stereo, you may need to buy a mono BACK to stereo adapter that you'll use on the one plug the single channel of audio is coming out of, like so: https://www.amazon.com/C2G-Cables-03174-Stereo-Adapter/dp/B0002EOHX0/

$10 hardware solution, you could probably even find cheaper options if you spend the time.

Answer 9

I found a solution (if u have this right ear/left ear problem), go to recording devices - from there your microphone (or line) from there advanced and 1 channel 16 bit 48000 hz (dvd quality) <3

Answer 10

If you're using Google Chrome, there is an extension that allows you to switch sound to mono (as well as control EQ, which is helpful if there is high pitched buzz or anything like that).

http://lab.ejci.net/Chrome-Audio-EQ/

once you install the extension, you have to reload the page, then it will be in mono!

Answer 11

On Mac OS Sonoma 14.5,

System Settings > Accessibility > Audio > "Play stereo audio as mono"

Answer 12

I have a solution for you but this is a paid software

This software might will be a sure fix: http://www.fxsound.com/dfx/index.php

I've used the software for a year now and has made my audio experience with my headphones waaaaaaaaay better. I'd say it's worth the 30$. Don't use this on games though, there's a configurable delay on the sound but the minimum delay you can get is 10ms and you might get clicking issues with that delay.

I just tested the video you are referring to without and with DFX and it do apply the sound in both channels.

Just turn 3D surround on and the sound will play on both left and right

Answer 13

A 2 dollar jack splitter solved this problem for me.

Answer 14

Here is a simple foolproof way to resolve that.

1. Right click on in task bar.
2. Right click on active audio device and click on
3. Click on tab
4. In the tab, in the drop down menu choose <1 channel, 16 bit,....>
5. Click

Done

Change it back when you are done :-)