I had exactly the same problem, it seems the channels twisted, at least somewhere in the automatic presets.
I have this for month… and try a lot of things with pulseaudio till i go back to what i would have tried in times prior pulseaudio ;)
Ha ha! It’s a bit confusing that some channels would be muted by default. Thanks for sharing your solutions! :D
First check that no output channels for your sound card are muted with alsamixer. https://wiki.archlinux.org/index.php/Advanced_Linux_Sound_Architecture
There were some that were muted but I unmuted and rebooted and it’s still not working. I also tried to change default soundcard using asoundconf-gtk (there’s an HDMI one on my system as well) but that didn’t work either.
This is my first time experimenting with Antergos, I used to use Ubuntu before.
I have a strange bug. Usually speakers work well and issues happen with earphones but now it’s the opposite. I have no sound in speakers but when I plug my earphones in, they work fine.
Stranger than that, the only audio output on my system is for the headphones. (I took a screenshot but I don’t have enough privilege to upload it so you’ll have to take my word for it).
I haven’t found an answer yet (as it’s usually the opposite that happens).
What can I do?
I also noticed that, in Volume Control the Speakers are listed as “Speakers (Unavailable)”.
The system was installed this morning and uses pulseaudio (I haven’t installed anything else).