Step 2. Click "Music" at the bottom bar and choose "MP3" among these audio formats. Step 3. Double-click on the MP3 format icon to open Codec options. Set the sample rate, bit rate, and audio channel the same as the source M4A file. Also, you can drag the slider under "Quality" to improve the sound quality. 5nvCr.

how to convert wav to mp3 in windows media player