That last comment really has me quite confused. What burning program do you use? Does your burning program automatically convert your mp3 file into the necessary .wav file format so you can play the CD in a regular CD player?
From what I know, mp3 format is your data format. It is a compressed format that only your computer or mp3 players can play. All CDs you buy at the store have the songs in .wav format. This format is must larger, usually about 32 MB in size or so for a song and this allows you to play your CD in a regular CD player. Your mp3s must be converted at some point if you are burning them onto a CD as an audio CD. An interesting note to make is that when you convert an mp3 to .wav format, it doesn't matter what the quality of the mp3 is. The size of the .wav file will always be the same. An mp3 with a bitrate of 128 will produce the same sized .wav file as an mp3 with a bitrate of 256. The quality of the playback of a .wav file will vary, but the size of the .wav file will not. That is why CDRs are labeled 80 Minute, .wav format has a ratio directly with time. A certain sized .wav file will also be the same length, unlike a mp3 file which can vary in size depending on the quality, but still have the same time length.
I will ask you to do one thing. The CD that you burned 32 songs on that had only 52.2 MB on it. Can this CD be played in a regular CD player. If so, flip the CD over and look at how much of the CD was actually burned. A CD starts burning from the center to the outside. I bet you most, if not all of the CD is used up. Meaning, the format was changed from mp3 to .wav and you actually did use up almost 700MB.
I will frequently use a CDR as storage for my mp3s. I can fit roughly 150 mp3's on a CD. But I cannot play this CD in a regular CD player. If I burn .wav formated song files onto a CD so I can play the CD in a regular CD player, and I can only fit about 20 songs, depending on the size or length of each song.
If you have any other questions just let me know.
Barryna