Sound problem: Microphone input gives low quality output

[Joel Hammer]

I am trying to get clear sound coming from a microphone, connected to my
sound card, and playing through speakers connected to the sound card. I have
tried two different computers with different sound cards and
speakers  and two different  microphones (cheap pc microphones) and
the result is the same.  I have to hold my mouth right up against the
microphone to get any output from the speakers. This is associated with
considerable distortion of the sound (words). I have played with
every knob in kmixer, but nothing changes for the better.

Audio files (mp3's, really) play on both these computers with no garbled
sounds.

Any suggestions appreciated,

Joel