I encode my sets as wave format, but this isn't practical for sharing my sets with people across the internet. Would you rather have to dl a 700MB set or a 100MB set?

The way that MP3 encoding works is by eliminating all the sounds that you can't hear. So all sounds below 20Hz and above 20,000Hz are eliminated. Also, let's say there is a flute playing and a very heavy bass beat hits. There will be a time in which you won't be able to hear the flute playing, so the encoding eliminates it. It does this more and more at lower bitrates, hence creating a smaller size file, but with less quality.