So you been using Linux and changed hardware or have decided to make the jump and try out Linux on hardware directly. Everything is working great, but sound is only coming from one speaker. What gives? Don’t worry, there is an easy fix for that.
This issue is caused by a bug in the sound software Alsa which is part of the Linux kernel. There are some specific set ups that cause the sound levels to be improperly set depending on your sound card. I discovered it by running an old Sound Blaster Audigy SE card in my machine. Ok, so how to fix it? Easy:
Open up a terminal and run the following command:
This will open up the terminal mixer application where you can set the levels for each output on the card. These options may be available in some GUI apps, however I am not aware of any myself and this is generally a one time set up so I have only used the terminal method.
In the terminal app, you can see it is a basic keyboard GUI app.
Now use F6 to find your sound card that you are using. This should open a window listing all available sound devices. Use the arrow keys to select your card.
Don’t see your device? It may be named differently than expected. So if you don’t see it you can open another terminal and type the following command:
This command will list your PCI hardware information (ls like the list command, PCI for PCI devices is how to remember it) and somewhere in the list will show you the name or part of the name that is used in AlsaMixer. Below you can see that my sound card name contains the CA0106 that is shown in the drop down list in the mixer.
If you still don’t see your sound card or it’s name, unfortunately that means there is a bigger problem than what this article will cover.
Ok, now back to AlsaMixer and having selected your sound card you will see something like whats shown below. Where only half of the colored bars are shown at volume.
Now you will want to use the arrow keys to select the affected levels and you can then set them using the arrow keys or by pressing any number key. If you use the arrow keys you will need to drop the bars all the way to 0 or 100 and then back down to get them equal and using the number keys will set both to the same level immediately. So to do this the fastest just press the right arrow key and then something like 6 to put the level at 60%. Why 60? I picked that mainly because 63 was set as the default level for my left speaker in Alsa. Once done you can then press ESC to quit.
That’s it! You should now be able to go into your sound manager app and test that it is now indeed working.
This issue is really an easy thing to fix, but one that isn’t exactly straight forward for those who aren’t in the know. So hopefully you found this helpful. At least you may have learned some new Linux commands 😉 . If this article helped you, I would love to hear about it in the comments below! If you have any questions, feel free to drop them below as well.