[nmglug] Fixed the mic

Akkana Peck akkana at shallowsky.com
Sat Jul 4 08:42:45 PDT 2020

Ted Pomeroy writes:
> NMGLugers, I had trouble with my mic in Xubuntu 20.04 during our July 2nd
> meeting. I have resolved this today, but the route was convoluted so I
> cannot be sure which step was the most likely single solution. My first

Audio has gotten insanely complicated lately -- I feel your pain
and I'm glad you got it working.

> choice for the solution is the Pulseaudio mixer where I found the "Input
> Devices" tab and un-checked the "Set as fallback" choice. As this was the

I found the "Set as fallback" buttons unhelpful in pavucontrol
(probably the same app you're using as Pulseaudio mixer) because
it doesn't give you any way of finding out what the current fallback is.
Did I press the button, or not? Which one did I make the fallback?
Did it remember it from last time? (Sometimes it does, other times not.)

I got so frustrated that I ended up writing a web page where I
collected what I'd learned about pulseaudio, pacmd and pactl:
and I wrote a script called pulsehelper to list audio source/sink
status and set fallbacks:

Setting the fallbacks right doesn't always help with Zoom or Jitsi,
though, because pulse also keeps a memory of which app uses which
device, so even if I set the default mic to be the GoPro, pulse may
decide that chromium should be using the built-in mic even though
it's muted. So I always have to check the audio prefs immediately
after starting zoom, jitsi or discord to make sure it's using
"System default" instead of some specific device.

> install the gui for the Alsamixer and to adjust the "Capture" level. It
> took a few tries in  the Alsamixergui to get the Alsamixer to respond, but
> this is simpler than manually adjusting the /usr/share/alsa/alsa.conf.d

Adding to the complication, it varies with every release. Under
Ubuntu 19.10, I couldn't adjust volume in pavucontrol at all. I used
use pavucontrol to set which speakers (sinks) and which microphone
(source) was active, but the volume sliders did nothing, and I had
to run alsamixer (or amixer from the commandline) to adjust volume.
I bound my laptop's Vol+ key to "amixer sset PCM 4%+ unmute" and
similarly for Vol- and mute. Now, in 20.04, alsamixer/amixer don't
change the volume at all; I still need to find pulse commands that I
can bind to my laptop's volume buttons.


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