Hmm, I am no true CD-freak, but I do know a lot about this. Howcome four CDs? That would hold true if you tried to burn the waves back to disc as a mode 1 data discs with error correction or as roadworker correctly mentions forget to set the pre track gaps to 00:00 apart from on the first track (that should always be 02:00 according to the Red book standard).
I am a bit puzzled as to what you're referring to I must say... Are you referring to the file size? We all know that it reads 650 or for the most, 700MB for CD-R these days, but it is simply not the case when it comes to Audio. 650 and 700MB refers to burning as Mode 1 data recording with error correction. CD-DA does not include error correction, it is simply a raw stream referring to the next sector of audio data without any error correction at all.
I choose to give you the facts pure and simple as I am not quite sure I understand your question, but for the record:
(650MB) 74 minutes (CD-DA) = 746.9 MB
(700MB) 80 minutes (CD-DA) = 807.5 MB
Hopefully the above is able to guide you as to what is possible on a CD-R (it is the absolute maximum), I would of course on a general level advice you to stop a tad before the absolute maximum if you want it to last (finger marks and all, but please note that the Wave header is stripped upon burning). :flower: