Microphone

From openSUSE

Microphone Settings in openSuse

With openSUSE 11.1, KDE4 started to use the Phonon backend for handling interactions between the sound devices such as the microphone and the applications. However, it is still possible to have a look around at the internals of your installation and find out what kind of mic you have installed. This is the first step to discovering how to set it up.

 lspci

This command will indicate which PCI based devices you have installed. This will likely include a graphics card, usb hubs and so on. You are looking for something that indicates the entry for the microphone controller.

For a more verbose output, one can also use:

 lspci -v

or for more

 lspci -vv

or for more

 lspci -vvv

If you are using a usb based microphone then it may not show up here. You will have to type in

 lsusb

in order to see what is the name of the usb device that is controlling your microphone. This will help you identify the chip name of your microphone device. You can use this to find the appropriate drivers.

For more verbose output, one can also use:

 lsusb -v

Kmix settings

Open the Kmix program and press the mixer button at the bottom. This will open a new and more detailed mixer. In this dialogue it will be possible to play around with the settings. In most installs the microphone is muted by default. Make sure that you select the radio button to undo this. If you find the microphone is still quiet then select the Mic Boost radio button to increase the volume of the microphone. You should also ensure that no other line in has the capture radio button selected, as this will at the very least interfere with your microphones quality.

Note the mixer (kmix) in kde4 has a menu item where one can add additional channels, providing additional mixer controls.

KRecord and testing the input levels

KRecord is a KDE3 based program that allows users to record from the capture stream and therefore can be used to test the microphone on your openSuSE linux computer. Once you have opened KRecord select the input level and freq spectrum buttons in the main interface. Now when you click record you should see if the microphone is having any effect on the spectrum and therefore whether or not your microphone is working. This tool, KRecord is great for testing microphone set ups and configuration under linux.

arecord and testing the input levels

Often it is useful to use a program that is desktop and application independant, when testing the microphone's basic functionality. A good program for this is the terminal arecord. Open a konsole or terminal, and type:

  arecord -vv -fdat foo.wav

where "foo.wav" is a file that will be recorded in the directory in which you were located at the command prompt of the terminal/konsole. The -vv option means the verbose output just like aplay, -fdat means 48kHz, 2-channel, 16bit format. It shows a VU-peak meter, so you will see usually what is being recorded. Push Ctrl-C to quit the recording; otherwise it'll continue endlessly. After finishing the recording, try to play back the file via aplay again. The reference for this is the alsa sound card testing page

Improving the quality of Microphone Capture under Linux

Text TBD.