Hi all! I became a member of What.CD and as you probably know it's not easy to get a good ratio there, and they are very strict with what you may upload. Since I have no unique music content I thought I'd upload my audiobook collection. I was a member of Audible for several years and have plenty of ripped material from there. The problem is, I ripped everything to 48 kbps m4b files which in my opinion is the optimal format for audiobooks. But What.CD accepts only flac mp3 and aac ! So what should I do? Of course, I could convert everything to mp3 but I use very long files. A book that is 12 hour long would then consist of two six hour mp3. Very odd, I think! What do you think? Or is .aac the best choice? I don't know anything about aac. Is it perhaps eaiser to convert from .m4b to .aac than to mp3. What are the pros and cons of aac? What would you recommend me to do? I don't have the original .aa files anymore - no need to hang on to them after a successful rip. Advice gratefully recieved! Hope you can think of what would be the best option.