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).

  • Does it make a difference when you set the speaker setup to "Laptop mono speakers" in this screen: worldwide.bose.com/productsupport/assets/images/articles/… (Control Panel -> Sounds and Audio Devices)? May 6, 2013 at 8:14
  • @StefanSeidel no change.
    – jakub.g
    May 6, 2013 at 20:07
  • On Android, go to setting, accessibility, mono audio. Exact path may vary depending on Android version, but it is there in recent ones. On ipados 13, go to setting, accessibility, audio/visual, mono audio
    – Prem
    Sep 28, 2020 at 12:52
  • Old question but if it's only for youtube the modern & fastest way is to install a browser extension like audio equalizer for firefox.
    – Hulkiorra
    Jun 13, 2021 at 20:03

14 Answers 14


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 :)

  • 11
    Can't use with bluetooth headset.
    – rr-
    Oct 28, 2015 at 11:35
  • 3
    @rr- ... or with USB headsets. Jun 1, 2016 at 12:50
  • Works for Macbook Pro (Youtube) Mar 31 at 14:54

Windows 10:

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

ease of access audio windows settings enable mono audio windows 10

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

  • @user26398 That's how music has been normally done for the last 60 years: "stereo" Sep 9, 2020 at 18:57
  • en.wikipedia.org/wiki/The_Beatles_in_Mono The Beatles in Mono was released to reflect the fact that most of the Beatles' catalogue was originally mixed and released in the monophonic format. Stereo recordings were a fairly new concept for pop music in the 1960s and did not become standard until late in that decade. This explains why the Beatles' initial album releases were mixed for mono.
    – user26398
    Sep 11, 2020 at 2:02

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".

enter image description here

(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.)


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.

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


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)

  • 2
    I'll very formally and happily explain. Because mono sound is only 1 sound stream. only surround sound (stereo) can output two different streams of audio. stereo mode is exactly how it's possible to get one sound in one ear, no sound in the other. by selecting mono, all the audio has to output in mono. in one stream. so that gets sent to both speakers. you didn't think they designed an audio output entirely to disregard one of the headphone speakers did you? did you try my solution? at least try first before you complain that i'm wrong. it absolutely does work. trust me.
    – MammaBear
    Jan 1, 2018 at 16:20
  • 2
    >Turn mono audio on or off >Mono audio >On >listen to youtube.com/watch?v=CBbYIY6FKKM
    – MammaBear
    Jan 1, 2018 at 16:22
  • On Windows 7, when I go to the Start Menu and type mono, I get the “Manage audio devices” control panel, and a bunch of unrelated things (e.g., files with “monogram” or “monologue” in their names).  When I go into the “Manage audio devices” control panel, I don’t see any option to enable mono.  Are you describing a Windows XP interface that no longer exists? or a Windows 10 interface that’s new?  Exactly how does a user “enable mono”? Please do not respond in comments; edit your answer to make it clearer and more complete. Jan 1, 2018 at 23:05
  • 2
    this appears to be a duplicate answer of superuser.com/a/1242781/26398 Windows Settings>Ease of access> Other options> Audio options: Turn mono audio "ON".
    – user26398
    Jun 5, 2019 at 22:32

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.

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


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.


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


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).


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


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


A 2 dollar jack splitter solved this problem for me.

enter image description here

  • I have one, still no change for me (maybe I have a wrong type, don't know).
    – jakub.g
    May 8, 2013 at 10:02
  • You would need to get a stereo to mono splitter for this to work Oct 19, 2016 at 4:02

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


Change it back when you are done :-)

  • Makes no sense?
    – Reado
    Nov 13, 2017 at 15:06

I wrote a program for this. It uses Equalizer APO library. https://www.faizamer.my/audio-channel-changer/

  • 2
    If you are going to promote your own product here please provide a link to a page that is in English.
    – DavidPostill
    Feb 20, 2017 at 11:04

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