With 6 disks, you may also have an issue with the tracks playing in the correct order, so I’ll offer another suggestion: download mp3tag(Mp3tag - the universal Tag Editor (ID3v2, MP4, OGG, FLAC, ...)) to edit id3 tags to get track numbers, etc, in the right order spanning multiple CDs. (Thanks, TomJensen, for this solution.)
Make a folder for your book. Rip each CD into subfolders called CD01, CD02, CD03, etc (if you have 100+ CDs, use enough leading zeros: CD001, CD002). How you do this depends on your Rip software. You may have to rename the folders after you rip the CDs.
In MP3Tag, open all of the folders (File | Change Directory to your book’s folder - all tracks in the subfolders will be opened), and Select all files (Ctrl-A).
On the menu, select Convert | Tag - Filename (Alt-1). Enter %_directory% %_filename% . Click OK. The filenames should now be prepended with the directory name so the tracks can sort properly in order of CD number. Click on the Filename bar twice to reorder the files to ascending order.
With all files selected, you can now use the Tools | Auto-numbering Wizard (Ctrl-K) to set the track numbers appropriately (use leading zeros).
While you’re at it, set author/Artist & book/Album name tags if they’re not correctly set, as well as genre to “Audiobook”, by changing the appropriate fields on the left side. Don’t forget to Save your changes.
Now drop & drag your audiobook folders & files into the Clip’s \Audiobooks folder. The Clip will now be able to properly identify each track by the id3 tags.
