Quake 3 Mixer Settings
If you do not need to use TeamSpeak or Ventrilo while you are playing Quake 3, then you probably do not need to adjust your mixer settings - in which case you can ignore this page.
This page will help setup your sound mixer so that you can play Quake 3 and use voice communication programs (TeamSpeak/Ventrilo) at the same time.
All this page is concerned with is what the most important mixer settings are, and which tool to use to get the job done.
KMix Screenshots:  /  / 
If your KMix shows most or all of the same settings that are shown in the above screenshots, then you can keep using KMix and avoid ALSA Mixer completely.
Output Tab: "Mic" must be completely off,
Input Tab: "PCM" must be completely off, "Mic" should be 90% or so.
Switches Tab: "Mic Boost +20dB" might need to be enabled if people can't hear you very well.
KMix Important Settings Screenshots:  /  / 
If you can make all of these adjustments, please skip all of the ALSA Mixer section below.
If your KMix doesn't include all of the settings mentioned, please read the ALSA Mixer section below.
To use ALSA Mixer you will need to temporarily close KMix. After everything is working and continues to work properly you can start using KMix again, if you want to.
A text based mixer lol. I know it sux. You might want to maximize the terminal window to have a better view of everything in ALSA Mixer.
IMPORTANT: To exit ALSA Mixer correctly, you always have to hit the ESCAPE key. If you click the X button to close the terminal window you will end up with a "stuck" alsamixer process running hidden. You can use ksysguard to check for stuck processes.
Basic usage tips...
TAB switches mixer "modes" between Playback, Capture and ALL (up at the top).
The left and right arrow keys navigate the controls.
The up and down arrow keys adjust the control levels.
Playback Settings: "Mic Playback" should be 0% (off) and "Mic Boost" will probably need to be set to "00" (on) which is +20dB (hit M to toggle on/off)
Capture Settings: "PCM Capture" should be 0% (off) and Mic Capture should be 90% or so.
Here are some screenshots that show the settings mentioned above:
Playback Screenshots:  / 
Capture Screenshots: 
ALL (Payback + Capture):  /  /