Foolestroupe, if you're using a computer mic, the quality will be such that the effects of the MP3 conversion are utterly insignificant. Computer mics are acceptable quality for voice, but you wouldn't use them for proper music recording. And at 56Kb, the "lossyness" of the MP3 format will be a fart in a hurricane compared to the effects of the microphone.

Also there's the size issue. 400K will give you a recording time measured in seconds not minutes.

Graham.