I wrote this when I was new to Ubuntu. Most of the time people are having microphone problems it is from driver problems and not just the sound settings as described in this guide. I'm leaving the guide up because it contains some potentially useful information for a small minority of newcomers.
A big thanks to pppoe_dude who initially helped me get my microphone working on IRC when I didn't know what I was doing.
This Guide is specifically for Ubuntu (GNOME).If you have a problem then say what steps you tried and what didn't work about it. For instance, you should make your post as specific as possible: "I tried enabling all of the check boxes in the preferences but after I raised the volume and turned the "Capture on" for the "Capture Control" I still don't have my mic working!". Without such information it is impossible to diagnose anything. Finally, you can attach a screenshot if you're confused (Alt+PrintScreen).
Overall Objective: Explain how to enable and configure the microphone capture for a sound card.
Specific Objective: Enable hidden sound channels, raise the volume and enable the capture for them, and test the microphone.
If all else fails, use alsamixer (console) to select which channels to capture from.
Finally, "Common Fixes" are listed at the bottom.
Before you do this, you'll want to make sure your Sound Capture in System-->Preferences-->Sound is set to ALSA (or OSS if you know ALSA doesn't work for some reason).
Goto your Volume Control
Goto Edit-->Preferences inside the volume control and check every check box.
(The controls you need to enable may be named something such as "Microphone", "Mix Capture", "Capture", or "Front Mic". If you are unsure then just enable everything.)
(For instance, if you hear yourself echoing when you have a playback control called "Analog Mix" enabled, the control that needs to be enabled will be named something like "Analog Mix Capture" or "Analog Mix Mic".)
Now, click on the Capture tab and you should see a few (or a lot!) of controls here. Make sure every control on the Capture tab doesn't have an
"X" on the microphone icon. Now, raise the volume of each control to maximum.
[Sidenote: On one of my sound cards I have the PCM's Capture (the microphone icon) turned off because that Captures (records) anything that
is playing on my speakers.]
My Audigy 4 Non-Pro's Capture settings:
My nForce2 sound card's Capture settings:
Now, on the Switches tab you'll want to make sure "Mic Boost (+20dB)" and "Microphone Capture" are checked (if you have them).
My Audigy 4 Switches Tab:
My nForce2 Switches Tab:
Hopefully, now your microphone works! You can test your settings by running
on the shell. You should see vumeter light up while you tap on the microphone (I recommend tapping in case there is a temporary problem with the capture volume being too low). If you change your sound settings correctly, you should immediately be able to see your microphone activity on the vumeter (without restarting vumeter, that is).Code:vumeter -r &
Finally, if you are still having problems, your capture may be set on the wrong channels.
Originally Posted by danielph
Here are screenshots from alsamixer for each of my soundcards.
List of other common fixes:
Enable "Full Duplex" for your sound card.
Disabling "IEC958" on the capture tab.
In Volume Control, when you goto File-->Change Device.. make sure your (Alsa mixer) is the device enabled.
If anyone has criticisms or additions to this post I'll update it.