Cd audio does not relate to bitrates used for compression methods. It is basically stored in wav format at a sample rate of 44100, and a bit depth of 16. If your relating this to how it sounds, its about the same quality you would get from 192kb mp3, (most people say 128, but i beg to differ).

Best thing to do is record your mix of whatever going onto cd as a 16 bit, 44100 wav, and that way you wont lose any quality through needless compression..