Why does my microphone max out at 50% volume?

EDIT: I believe the problem is that my mic is a mono input and it is being treated as stereo, so it is only 50% volume because of this.

I am running Ubuntu 22.04.

I have a Blue enCORE 100i plugged into a Presonus AudioBox USB.

My Microphone volume never exceeds 50% at the OS. In the following screenshot you can see this is the maximum that the volume of the mic will go. The screenshot was taken while sound input was maximum at the mic (shouting "Why won't this work!!" lol).

On the AudioBox USB device, there is a clipping indicator light that indicates when the mic input exceeds max level. My clipping indicator light is going off, indicating that at the Audio interface, the microphone volume is max. But at the OS level it is only at 50%.

If I increase the gain in pavucontrol over 100% (as depicted) the max volume still stays at 50%. If I reduce the gain back down to 100%, the max volume is still 50%.

The output of pactl info is...

Server String: /run/user/1000/pulse/native 
Library Protocol Version: 35 
Server Protocol Version: 35
Is Local: yes
Client Index: 30 
Tile Size: 65472
User Name: scott
Host Name: main-desktop
Server Name: pulseaudio Server
Version: 15.99.1
Default Sample Specification: s16le 2ch 48000Hz
Default Channel Map: front-left,front-right
Default Sink: alsa_output.usb-PreSonus_Audio_AudioBox_USB-01.iec958-stereo
Default Source: alsa_input.usb-PreSonus_Audio_AudioBox_USB-01.analog-stereo
Cookie: 8641:298c

Help on troubleshooting/diagnose of the problem

I'm on Ubuntu 22.04 Jammy Jellyfish (x86-64) with Cinnamon 5.2.7

When I do:

• ps -e | grep pipewire

  2640 ?        00:00:00 pipewire
  2641 ?        00:00:00 pipewire-media-
  

• ps -e | grep audio

  2642 ?        00:17:13 pulseaudio
  

• ps -e | grep alsa

  nothing
  

Could you compare?

I presume sor far you use pulsaudio principaly, and think this might help:

If you experience low volume on your microphone try setting: nano /etc/pulse/default.pa

with: set-source-volume 1 300000

Reference: https://wiki.archlinux.org/title/PulseAudio/Troubleshooting

You could also check the setting in:

/usr/share/pulseaudio/alsa-mixer/paths/analog-output.conf.common

Look for volume = merge or ignore on your system ?

After changing it you should killall pulseaudio

Pulsaudio will restart on its own and you'll be able to try.

Normally it's advised to set ignore because the volume output of the microsophone is too high.

(Reference in french)

If you try to make the input stereo instead of mono, I've found this post about adding a channel to an audio input.

Microphones convert sound waves to audio signals via mic capsules. Most mics have one capsule that outputs one signal, making them mono devices. Some mics have multiple capsules and output multiple mono signals (which could be mixed in stereo). However, “stereo mics” are truly multiple-mono devices. Source